ISO 19694-6:2023

Stationary source emissions — Determination of greenhouse gas emissions in energy-intensive industries — Part 6: Ferroalloys and silicon industry

This document provides a harmonized methodology for calculating GHG emissions from the ferro-alloys industry based on the mass balance approach. This document also provides key performance indicators over time for ferro-alloys plants. This document covers the following direct and indirect sources of GHG: — direct GHG emissions [see ISO 14064-1:2018, 5.2.4 a)] from sources that are owned or controlled by the company, such as emissions resulting from the following sources: — smelting (reduction) process; — decomposition of carbonates inside the furnace; — auxiliaries operation related to the smelting operation (i.e. aggregates, drying processes, heating of ladles, etc.); — indirect GHG emissions [see ISO 14064-1:2018, 5.2.4 b)] from the generation of purchased electricity consumed in the company’s owned or controlled equipment.

Émissions de sources fixes — Détermination des émissions des gaz à effet de serre dans les industries à forte intensité énergétique — Partie 6: Industrie des ferro-alliages et du silicium

General Information

• Status: Published
• Publication Date: 28-Feb-2023
• ICS: 13.020.40 - Pollution, pollution control and conservation
• ICS: 13.040.40 - Stationary source emissions
• Technical Committee: ISO/TC 146/SC 1 - Stationary source emissions
• Drafting Committee: ISO/TC 146/SC 1/WG 30 - GHG energy-intensive industries – Specific sectors
• Current Stage: 6060 - International Standard published
• Start Date: 01-Mar-2023
• Due Date: 16-Feb-2022
• Completion Date: 01-Mar-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 19694-6
First edition
2023-03
Stationary source emissions —
Determination of greenhouse gas
emissions in energy-intensive
industries —
Part 6:
Ferroalloys and silicon industry
Émissions de sources fixes — Détermination des émissions des gaz à
effet de serre dans les industries à forte intensité énergétique —
Partie 6: Industrie des ferro-alliages et du silicium
Reference number
ISO 19694-6:2023(E)
© ISO 2023
---------------------- Page: 1 ----------------------
ISO 19694-6:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
© ISO 2023 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 19694-6:2023(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 S c op e ................................................................................................................................................................................................................................. 1

2 Nor m at i ve r ef er enc e s ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Abbreviated terms ............................................................................................................................................................................................. 3

5 D etermination of GHGs — Principles ............................................................................................................................................. 4

5 .1 I nt r o duc t ion .............................................................................................................................................................................................. 4

5.2 General ........................................................................................................................................................................................................... 4

5.3 D etermination based on mass balance ............................................................................................................................. 4

5.4 U se of waste gas/heat recovery .............................................................................................................................................. 4

6 B ou nd a r ie s ................................................................................................................................................................................................................. 4

6.1 General ........................................................................................................................................................................................................... 4

6 . 2 O p er at ion a l b ou nd a r ie s ........................................................................................................................................... ....................... 5

6 . 3 O r g a n i z at ion a l b ou nd a r ie s .......................................................................................................................................................... 5

7 D irect emissions and their determination............................................................................................................................... 6

7.1 G eneral ........................................................................................................................................................................................................... 6

7.2 M ass balance approach ................................................................................................................................................................... 6

7.2.1 G eneric approach ............................................................................................................................................................... 6

7. 2 . 2 S a mpl in g .................................................................................................................................................................................... 7

7. 2 . 3 A lt er n at e appr o ac h........................................................................................................................................................... 7

7. 3 P r o c e s s em i s s ion s ................................................................................................................................................................................ 9

7. 3 .1 O ver v iew ................................................................................................................................................................................... 9

7. 3 . 2 Me t ho d s ...................................................................................................................................................................................... 9

7.4 C ombu s t ion em i s s ion s .................................................................................................................................................................. 10

7.4 .1 O ver v iew ................................................................................................................................................................................ 10

7.4 . 2 Me t ho d s ................................................................................................................................................................................... 10

7.4.3 Calculation of the quantity of fuel .................................................................................................................... 11

7.4.4 D etermination of the lower calorific value and the emission factor .................................12

7.4.5 D etermination of the oxidation factor .........................................................................................................12

7.5 Combustion of biomass fuels ..................................................................................................................................................12

8 I ndi r e c t emi s s ions ...........................................................................................................................................................................................12

8.1 General ........................................................................................................................................................................................................12

8 . 2 CO from external electricity production ....................................................................................................................12

8.2.1 General .....................................................................................................................................................................................12

8.2.2 G HG from heat transfer .............................................................................................................................................13

9 B aselines, acquisitions and disinvestments ........................................................................................................................13

10 R ep or t i n g ..................................................................................................................................................................................................................13

10.1 G eneral ........................................................................................................................................................................................................13

10 . 2 R epor t i ng per io d s ............................................................................................................................................................................. 14

10 . 3 Per f or m a nc e i nd ic at or s ............................................................................................................................................................... 14

10.3.1 General ..................................................................................................................................................................................... 14

10.3.2 Denominator for specific, unit-based emissions .................................................................................15

10.3.3 Denominator for other ratio indicators ...................................................................................................... 15

10.3.4 Key performance indicators .................................................................................................................................. 15

10.3.5 Recovery of waste gas and waste heat ........................................................................................................ 15

11 Uncertainty of GHG inventories ........................................................................................................................................................16

11.1 I ntroduction to uncertainty assessment ...................................................................................................................... 16

11.1.1 B a s ic c on s ider at ion s .................................................................................................................................................... 16

11.1.2 Materiality thresholds ................................................................................................................................................ 17

iii
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ISO 19694-6:2023(E)

11.2 U ncertainty of activity data ..................................................................................................................................................... 17

11.2.1 Measuring instruments for the determination of fuel and material

quantities ............................................................................................................................................................................... 17

11.2.2 Aggregated uncertainties in case of mass balances ........................................................................ 17

11.3 U ncertainties of fuel and material parameters ...................................................................................................... 18

11.4 E valuation of the overall uncertainty of an GHG inventory ........................................................................ 18

Annex A (normative) Tier 1 emission factors .........................................................................................................................................19

Annex B (normative) Minimum frequency of analyses.................................................................................................................21

Annex C (normative) Country-wise emission factors for electricity ..............................................................................22

Bibliography .............................................................................................................................................................................................................................26

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ISO 19694-6:2023(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,

Stationary source emissions.
A list of all parts in the ISO 19694 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2023 – All rights reserved
---------------------- Page: 5 ----------------------
ISO 19694-6:2023(E)
Introduction
0.1 Overview of the ferro-alloy manufacturing process

Ferroalloy production involves a metallurgical reduction process that results in significant carbon

dioxide emissions. These emissions are the results of a carbothermic reaction which is intrinsic to

the process. In ferroalloy production, ore, carbon materials and slag forming materials are mixed and

heated to high temperatures for smelting.

Smelting in an electric arc furnace is accomplished by conversion of electrical energy to heat. An

alternating current applied to the electrodes creates current to flow through the charge between the

electrode tips. The heat is produced by the electric arcs and by the resistance in the charge materials.

Emissions from the smelting process are therefore not to combustion emissions. The furnaces can be

open, semi-closed or closed. Submerged electric arc furnaces with graphite electrodes or self-baking

Søderberg electrodes are used (see Figure 1).

The reduction process is the main source of direct CO emissions. Other CO sources include direct

2 2

emissions from calcination of calcium, magnesium and other carbonates (e.g. limestone) in some

processes and from non-smelting fuels (e.g. dryers for ladles and refractory linings), room heating and

indirect emissions from, for example, external power production.
Figure 1 — Submerged electric arc furnace
0.2 CO from the smelting of raw materials

In the smelting process, CO is released due to the carbothermic reduction of the metallic oxides

occurring with the consumption of both carbonaceous reductants and carbon-based electrodes. The

carbon in the reductants reacts with oxygen from the metal oxides to form CO and then CO (in different

ways depending on the process), and the ores are reduced to molten base metals. For the calculation,

the assumption is that all CO is assumed to be converted in the furnace to CO .
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ISO 19694-6:2023(E)

The reductant carbon is used in the form of coke, coal, pet coke, anthracite, charcoal and wood chips.

The first four are fossil-based and the charcoal and wood chips are bio-carbon.

In the carbothermic process, only the fixed carbon content is used as a reducing agent, which means

that volatile matter, ashes and moisture mostly leave the furnace with the off-gas and slag.

The nature of reducing agents, price and electrodes depends on the localization of the plant, the raw

material availability and it is presented in Table 1. It is variable from one site to another and from one

year to another and also from one ferro-alloy to another.

Table 1 — Type of reducing agents and electrodes used in the electrometallurgy sector

Reducing agents Electrodes
Crude petroleum coke Graphite electrode
Calcinated petroleum coke Prebaked electrodes
Coal coke Søderberg paste
Coke from coal Composite electrode
Wood —
Calcinated wood —
Charcoal —
Graphite powder —
Anthracite —

CO emissions are estimated with and calculated from the consumption of the reducing agents and

electrodes, their carbon content, and the carbon content of the final products.

NOTE The basic calculation methods used in this document are compatible with the 2006 IPCC Guidelines

[1]

for National Greenhouse Gas Inventories issued by the Intergovernmental Panel on Climate Change (IPCC) .

Ores and reducing agent react to form ferro-alloys or metal, CO and dust and other by-product (i.e.

slags); amount of carbon can be found in the products

Default emission factors suggested in these documents are used, except where more recent, industry-

specific data has become available.
vii
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INTERNATIONAL STANDARD ISO 19694-6:2023(E)
Stationary source emissions — Determination of
greenhouse gas emissions in energy-intensive industries —
Part 6:
Ferroalloys and silicon industry
1 S cope

This document provides a harmonized methodology for calculating GHG emissions from the ferro-

alloys industry based on the mass balance approach. This document also provides key performance

indicators over time for ferro-alloys plants. This document covers the following direct and indirect

sources of GHG:

— direct GHG emissions [see ISO 14064-1:2018, 5.2.4 a)] from sources that are owned or controlled by

the company, such as emissions resulting from the following sources:
— smelting (reduction) process;
— decomposition of carbonates inside the furnace;

— auxiliaries operation related to the smelting operation (i.e. aggregates, drying processes,

heating of ladles, etc.);

— indirect GHG emissions [see ISO 14064-1:2018, 5.2.4 b)] from the generation of purchased electricity

consumed in the company’s owned or controlled equipment.
2 Normat ive references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 14064-1:2018, Greenhouse gases — Part 1: Specification with guidance at the organization level for

quantification and reporting of greenhouse gas emissions and removals

ISO/IEC 17025, 2005, General requirements for the competence of testing and calibration laboratories

ISO 19694-1:2021, Stationary source emissions — Determination of greenhouse gas emissions in energy-

intensive industries — Part 1: General aspects
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 19694-1:2021 and the

following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

For the purposes of this document, the terms and definitions in and the following apply.

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ISO 19694-6:2023(E)

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
auxiliary
equipment consuming electricity/power related to the smelting (3.5) process

EXAMPLE Fans, pumps, gas abatement systems (filter bags, venture scrubbers, etc.).

3.2
silica fume

amorphous silicon dioxide particles from the volatilization and vaporization of furnace feed materials

in the manufacture of ferrosilicon and silicon (3.4)

Note 1 to entry: The process off-gas that contains silica fumes beings cleaned in a baghouse using fabric filters of

the open or semi-closed SEAF (3.8).
3.3
ferro-alloy

alloy of iron and one or more metals such as silicon (3.4), manganese, chromium, molybdenum,

vanadium and tungsten
3.4
silicon

metalloid produced by carbo-thermic reduction of quartz in an electric submerged arc furnace

3.5
smelting

industrial process where one or more ores or ore concentrates are heated and reduced (i.e. chemically

modified) by, for example, aluminino-carbo-silico thermic reduction, to manufacture and mix the

metals in one step
Note 1 to entry: Examples of smelted alloys are ferro-alloys (3.3).
3.6
gross GHG emission

absolute fossil direct GHG emission excluding GHG emissions from on-site power production

3.7
absolute gross GHG emission

total direct emission of GHGs within the boundaries excluding GHG emissions from biogenic CO from

biomass (i.e. wood chips and charcoal)
3.8
submerged electric arc furnace
SEAF

electric arc-heating furnace in which the arcs are completely submerged under the charge

Note 1 to entry: The arc forms between the electrode [graphite electrodes or self-baking Søderberg electrodes

(3.12)] and metal surface or bottom lining. The heat being produced by the electric arcs and by the resistance in

the charge materials initiates the reduction process. The furnaces can be open, semi-closed or closed, which can

depend upon the ferro-alloy (3.3) to be produced.
3.9
biomass fuel
fuel with only biogenic carbon
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ISO 19694-6:2023(E)
3.10
petroleum coke
petcoke
carbon-based solid fuel derived from oil refineries
3.11
sinter
sintering
process to form a coherent mass by heating without melting
3.12
Søderberg electrode

continuously self-baking carbon electrode used in electro-metallurgical furnaces for production of

ferroalloys and silicon (3.4)

Note 1 to entry: The “Søderberg paste” is a preparation of coal tar pitch and carbonaceous dry aggregate.

3.13
composite electrode

electrode where the core is composed of graphite while the exterior is a self-baking carbon paste (which

is a “Søderberg paste”)
3.14
prebaked electrode

carbonaceous paste baked so as to carbonize coal tar pitch in order to form a solid pitch coke binder

phase

Note 1 to entry: A carbonaceous paste is a mixing of coal tar pitch with a dry carbonaceous aggregate.

4 Abbreviated terms
For the purposes of this document, the following abbreviations apply.
CO Carbon monoxide
CO Carbon dioxide
EF Emission factor
FA Ferro-alloys
GHG Greenhouse gases
HCV High calorific value
IEA International Energy Agency
IPCC Intergovernmental Panel on Climate Change
KPI Key performance indicator
SEAF Submerged electric arc furnace
UNFCCC United Nations Framework Convention on Climate Change
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ISO 19694-6:2023(E)
5 De termination of GHGs — Principles
5.1 Introduction

This document shall be used in conjunction with ISO 19694-1:2021 which contains generic, overall

requirements, definitions and rules applicable to the determination of GHG emissions for all energy-

intensive sectors, provides common methodological issues and specifies the details for applying the

rules. The application of this document to the sector-specific standards ensures accuracy, precision and

reproducibility of the results and is for this reason a normative reference standard.

5.2 General

The determination of CO emissions can be in principle done either through calculation (mass balance

method) or through stack emission measurement.

The methodology described in this document for GHG emissions determination is based on the mass

balance method (see 7.1).

CO is the only GHG relevant for the ferro-alloys industry. The emissions of CH and of N O are extremely

2 4 2
low. Therefore, they are both neglected in the calculation of carbon emissions.

The measurements of the concentrations of CH and N O have been demonstrated to be near or below

4 2

the detection limits during the field tests performed to develop this document with independent

[7]
laboratories .
5.3 Det ermination based on mass balance

In installations where carbon stemming from input materials used remains in the products or other

outputs of the production, for example, for the reduction of metal ores, a mass balance approach is

applied. In installations where this is not the case, combustion emissions and process emissions are

calculated separately.

Emissions from source streams are calculated from input or production data, obtained by means of

measurement systems and additional parameters from laboratory analyses including calorific factor,

carbon content and biomass content. Standard factors can also be used; references to these factors are

provided in ISO 19694-1:2021.
5.4 Use of w aste gas/heat recovery

GHG emissions related to waste gas and heat recovery are reported as direct GHG emissions. Waste

gas including CO and CO can be subtracted from the direct emission, when exported outside the

boundaries of the location, as a negative carbon flow in the mass balance (e.g. when exporting waste

gas to another installation).
6 Bo undaries
6.1 General

Drawing appropriate boundaries is one of the key tasks in an emissions inventory process.

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ISO 19694-6:2023(E)
6.2 Operational boundaries

Operational boundaries refer to the types of sources covered by an inventory. A key distinction between

direct and indirect emissions is the following.

a) Direct emissions [see ISO 14064-1:2018, 5.2.4 a)] are emissions from sources that are owned or

controlled by the reporting company. For example, emissions from smelting are direct emissions of

the company owning (or controlling) the furnace.

b) Indirect emissions [see ISO 14064-1:2018, 5.2.4 b) to f)] are emissions that result as a consequence

of the activities of the reporting company but occur at sources owned or controlled by another

company. For example, emissions from the generation of grid electricity consumed by a ferro-alloy

company qualify as indirect.

Clause 7 provides detailed guidance on the different sources of direct emissions occurring in ferro-

alloys plants. Indirect emissions are addressed in Clause 8.

Companies shall use the operational boundaries outlined in Table 2 and the relevant process steps

in Table 3, for the determination of the GHG emissions for the smelting/carbo-thermic reduction

operations part of the ferro-alloy plant. Any deviation from these boundaries shall be reported and

explained.
Table 2 — Operational boundaries
Included within boundaries Excluded
Smelting (carbo-thermic reduction): Mobile transport
— electrodes
— reducing agents
— non-furnace fuels

Electricity consumption for whole production process Room heating / cooling (negligible)

Onsite power production: waste heat recovery Mobile transport in plant
Stock inventories carbon materials —
Table 3 — Process steps
Process step Scope Inclusion GHG emission category
ISO 14064-1:2018, 5.2.4 a)
Smelting Scope 1 Yes a
Electricity consumption for whole
Scope 2 Yes b
production process
Onsite power production Scope 1 Yes a
Waste heat recovery Scope 1 Yes a
Room heating / cooling Scope 1 Yes, but negligible a
Stock changes Scope 1 Yes a
6.3 Organizational bou ndaries

The major source of GHG emissions in the ferroalloys sector is the process-related emissions from the

submerged electric arc furnaces operations, the reduction of the metallic oxides and the consumption of

the electrodes during the process. There are practically no fuel related process emissions and heat is a

negligible input factor in the production. The operational boundaries for this document GHG emissions

cover only the smelting/carbo-thermic reduction op
...

TC /SC
Date: 2022-01-20
TC /SC ISO/FDIS 19694-6:2022(E)
ISO/TC 146/SC 1
Secretariat: BIS
Stationary source emissions — Determination of greenhouse gas emissions in
energy-intensive industries — Part 6: Ferroalloys and silicon industry
First edition
Date: 2022-08-16
---------------------- Page: 1 ----------------------
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of

this publication may be reproduced or utilized otherwise in any form or by any means, electronic or

mechanical, including photocopying, or posting on the internet or an intranet, without prior written

permission. Permission can be requested from either ISO at the address below or ISO's member body in the

country of the requester.
ISO Copyright Office
CP 401 • CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: [e-mail]
Website: www.iso.org
Published in Switzerland.
---------------------- Page: 2 ----------------------
Contents Page

Foreword ...................................................................................................................................................................... 5

Introduction ................................................................................................................................................................ 6

1 Scope ................................................................................................................................................................ 1

2 Normative references ................................................................................................................................ 1

3 Terms and definitions ................................................................................................................................ 2

4 Symbols and abbreviated terms ............................................................................................................. 4

5 Determination of GHGs — Principles .................................................................................................... 4

5.1 General ............................................................................................................................................................ 4

5.2 Determination based on mass balance ................................................................................................. 5

5.3 Use of waste gas/heat recovery .............................................................................................................. 5

6 Boundaries .................................................................................................................................................... 5

6.1 General ............................................................................................................................................................ 5

6.2 Operational boundaries ............................................................................................................................ 5

6.3 Organizational boundaries ....................................................................................................................... 6

7 Direct emissions and their determination .......................................................................................... 6

7.1 General ............................................................................................................................................................ 6

7.2 Mass balance approach .............................................................................................................................. 7

7.2.1 Generic approach ........................................................................................................................................ 7

7.2.2 Sampling ......................................................................................................................................................... 8

7.2.3 Alternate approach ..................................................................................................................................... 8

7.3 Process emissions ..................................................................................................................................... 10

7.3.1 Overview ...................................................................................................................................................... 10

7.3.2 Methods ........................................................................................................................................................ 11

7.4 Combustion emissions ............................................................................................................................. 13

7.4.1 Overview ...................................................................................................................................................... 13

7.4.2 Methods ........................................................................................................................................................ 14

7.4.3 Calculation of the quantity of fuel ........................................................................................................ 15

7.4.4 Determination of the lower calorific value and the emission factor ........................................ 15

7.4.5 Determination of the oxidation factor ................................................................................................ 15

7.5 Combustion of biomass fuels ................................................................................................................. 15

8 Indirect emissions ..................................................................................................................................... 16

8.1 General .......................................................................................................................................................... 16

8.2 CO2 from external electricity production .......................................................................................... 16

8.2.1 General .......................................................................................................................................................... 16

8.2.2 GHG from heat transfer............................................................................................................................ 16

9 Baselines, acquisitions and disinvestments ..................................................................................... 17

10 Reporting ..................................................................................................................................................... 17

10.1 General .......................................................................................................................................................... 17

10.2 Reporting periods ..................................................................................................................................... 18

10.3 Performance indicators ........................................................................................................................... 18

10.3.1 Denominator for specific, unit-based emissions ............................................................................. 18

10.3.2 Denominator for other ratio indicators ............................................................................................. 19

10.3.3 key performance indicators ................................................................................................................... 19

iii
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10.3.4 Recovery of waste gas and waste heat ................................................................................................ 19

11 Uncertainty of GHG inventories ............................................................................................................ 20

11.1 Introduction to uncertainty assessment ............................................................................................ 20

11.1.1 Basic considerations ................................................................................................................................. 20

11.1.2 Materiality thresholds ............................................................................................................................. 22

11.2 Uncertainty of activity data .................................................................................................................... 22

11.2.1 Measuring instruments for the determination of fuel and material quantities .................... 22

11.2.2 Aggregated uncertainties in case of mass balances ........................................................................ 22

11.3 Uncertainties of fuel and material parameters ................................................................................ 22

11.4 Evaluation of the overall uncertainty of an GHG inventory ......................................................... 23

Annex A (normative) Tier 1 emission factors ............................................................................................... 24

Annex B (normative) Minimum frequency of analyses ............................................................................. 26

Annex C (normative) Country-wise emission factors for electricity ..................................................... 27

Bibliography .............................................................................................................................................................. 34

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Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national

standards bodies (ISO member bodies). The work of preparing International Standards is normally

carried out through ISO technical committees. Each member body interested in a subject for which a

technical committee has been established has the right to be represented on that committee.

International organizations, governmental and non-governmental, in liaison with ISO, also take part in

the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all

matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,

Stationary source emissions.
A list of all parts in the ISO 19694 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
---------------------- Page: 5 ----------------------
Introduction
0.1 Overview of the ferro-alloy manufacturing process

Ferroalloy production involves a metallurgical reduction process that results in significant carbon

dioxide emissions. These emissions are the results of a carbothermic reaction which is intrinsic to the

process. In ferroalloy production, ore, carbon materials and slag forming materials are mixed and

heated to high temperatures for smelting.

Smelting in an electric arc furnace is accomplished by conversion of electrical energy to heat. An

alternating current applied to the electrodes creates current to flow through the charge between the

electrode tips. The heat is produced by the electric arcs and by the resistance in the charge materials.

Emissions from the smelting process are therefore not to combustion emissions. The furnaces maycan

be open, semi-closed or closed. Submerged electric arc furnaces with graphite electrodes or self-baking

Søderberg electrodes are used (see Figure 1).

Submerged Electric Arc Furnaces (SEAF) with graphite electrodes or self- baking Søderberg electrodes

are used (see Figure 1).

The reduction process is the main source of direct CO emissions. Other CO sources include direct

2 2

emissions from calcination of calcium, magnesium and other carbonates (e.g. limestone) in some

processes and from non-smelting fuels (e.g. dryers for ladles and refractory linings), room heating, and

indirect emissions from e.g., for example, external power production.

The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location.

---------------------- Page: 6 ----------------------
Figure 1 — Submerged electric arc furnace (SEAF)
0.2 CO2 from the smelting of raw materials

In the smelting process, CO2 is released due to the carbothermic reduction of the metallic oxides

occurring with the consumption of both carbonaceous reductants and carbon-based electrodes. The

carbon in the reductants reacts with oxygen from the metal oxides to form CO and then CO (in different

ways depending on the process), and the ores are reduced to molten base metals. For calculation the

assumption is that all CO is assumed to be converted in the furnace to CO2.

The reductant carbon is used in the form of coke, coal, pet coke, anthracite, charcoal and wood chips.

The first four are fossil-based and the charcoal and wood chips are bio-carbon.

In the carbothermic process, only the fixed carbon content is used as a reducing agent, which means

that volatile matter, ashes and moisture mostly leave the furnace with the off-gas and slag.

The nature of reducing agents, price and electrodes is depending ofdepends on the localization of the

plant, the raw material availability and it is presented in Table 1. It is variable from one site to another

and from one year to another and also from one ferro-alloy to another.

Table 1 — Type of reducing agents and electrodes used in the electrometallurgy sector

Reducing agents Electrodes
Crude petroleum coke Graphite electrode
Calcinated petroleum coke Prebaked electrodes
Coal coke Søderberg paste
Coke from coal Composite electrode
Wood —
vii
---------------------- Page: 7 ----------------------
Calcinated wood —
Charcoal —
Graphite powder —
Anthracite —

CO emissions are estimated with/ and calculated from the consumption of the reducing agents and

electrodes, their carbon content and the carbon content of the final products.

ores +NOTE The basic calculation methods used in this document are compatible with the 2006 IPCC Guidelines

[1]

for National Greenhouse Gas Inventories issued by the Intergovernmental Panel on Climate Change (IPCC) .

Ores and reducing agent →react to form ferro-alloys/ or metal* +, CO +and dust/ and other by-product

(i.e. slags)*
*); amount of carbon can be found in the products

Default emission factors suggested in these documents are used, except where more recent, industry-

specific data has become available.
viii
---------------------- Page: 8 ----------------------
Stationary source emissions — Determination of greenhouse
gas emissions in energy-intensive industries — Part 6:
Ferroalloys and silicon industry
1 Scope

This document provides a harmonisedharmonized methodology for calculating GHG emissions from the

ferro-alloys industry based on the mass balance approach. ItThis document also provides key

performance indicators over time offor ferro-alloys plants. It addressesThis document covers the

following direct and indirect sources of GHG:

— (direct GHG emissions ([see ISO 14064-1:2018, 5.2.4 a – former Scope 1 -))] from sources that are

owned or controlled by the company, such as emissions resulting from the following sources:

— smelting (reduction) process;
— decomposition of carbonates inside the furnace;

— auxiliaries operation related to the smelting operation (i.e. aggregates, drying processes,

heating of ladles, etc.)..);

— indirect GHG emissions from ([see ISO 14064-1:2018, 5.2.4 b – former Scope 2 -):

— )] from the generation of purchased electricity consumed in the company’s owned or controlled

equipment.

This document shall be used in conjunction with ISO 19694-1:2021 which contains generic, overall

requirements, definitions and rules applicable to the determination of GHG emissions for all energy-

intensive sectors, provides common methodological issues and specifies the details for applying the

rules. The application of this standard to the sector-specific standards ensures accuracy, precision and

reproducibility of the results and is for this reason a normative reference standard. The requirements of

these standards do not supersede legislative requirements.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 19694-1:2021, Stationary source emissions — Determination of Greenhouse Gas (GHG) emissions in

energy intensive industries — Part 1: General aspects

ISO 14064--1:2018, Greenhouse gases — Part 1: Specification with guidance at the organization level for

quantification and reporting of greenhouse gas emissions and removals

ISO 17025, 2005, General requirements for the competence of testing and calibration laboratories

---------------------- Page: 9 ----------------------

ISO 19694-1:2021, Stationary source emissions — Determination of greenhouse gas emissions in energy-

intensive industries — Part 1: General aspects
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 19694--1:2021 and the

following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/

For the purposes of this document, the terms and definitions in and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
auxiliaries
auxiliary
equipment consuming electricity/power related to the smelting (3.5) process:

EXAMPLE Fans, pumps, gas abatement systems (filter bags, venture scrubbers …), etc.).

3.2
silica fume

amorphous silicon dioxide particles from the volatilization and vaporization of furnace feed materials in

the manufacture of ferrosilicon and silicon, (3.4)

Note 1 to entry: The process off-gas that contains silica fumes beings cleaned in a baghouse using fabric filters of

the open or semi-closed SEAF (3.8).
3.3
ferro-alloy

ferroalloy is the term used to describe concentrated alloysalloy of iron and one or more metals such as

silicon, (3.4), manganese, chromium, molybdenum, vanadium and tungsten
3.4
silicon

silicon is a metalloid produced by carbo-thermic reduction of quartz in an electric submerged arc

furnace
3.5
smelting

industrial process where one or more ores or ore concentrates are heated and reduced (i.e. chemically

modified) by e.g., for example, aluminino-carbo-silico thermic reduction –, to manufacture and mix the

metals in one step. Examples of smelted alloys are ferro-alloys
Note 1 to entry: Examples of smelted alloys are ferro-alloys (3.3).
3.6
---------------------- Page: 10 ----------------------
gross GHG emissionsemission

absolute gross fossil direct GHG emissionsemission excluding GHG emissions from on-site power

production
3.7
absolute gross GHG emissionsemission

total direct emissionsemission of GHGs within the boundaries excluding GHG emissions from biogenic

CO from biomass (i.e. wood chips and charcoal)
3.8
submerged electric arc furnace
SEAF

an electric arc-heating furnace in which the arcs are completely submerged under the charge.

Note 1 to entry: The arc forms between the electrode ([graphite electrodes or self-baking Søderberg electrodes)

(3.12)] and metal surface or bottom lining. The heat being produced by the electric arcs and by the resistance in

the charge materials initiates the reduction process. The furnaces maycan be open, semi-closed or closed, which

can depend upon the ferro-alloy (3.3) to be produced. A commonly used technology is the Submerged Electric Arc

Furnace (SEAF)
3.9
fossil fuels

all fossil fuels listed by IPCC or any fuel which contains organic and inorganic carbon that is not biomass

3.10
biomass fuels
fuelsbiomass fuel
fuel with only biogenic carbon
3.1110
petroleum coke
petcoke
petroleum coke, a carbon-based solid fuel derived from oil refineries
3.1211
sinter
sintering
Sinter
process to form a coherent mass by heating without melting
3.1312
Søderberg electrodeselectrode

a continuously self-baking carbon electrode used in electro-metallurgical furnaces for production of

ferroalloys and silicon (the “Søderberg paste” is a preparation of coal tar pitch and carbonaceous dry

aggregate)3.4)

Note 1 to entry: The “Søderberg paste” is a preparation of coal tar pitch and carbonaceous dry aggregate.

3.1413
composite electrodeselectrode

in composite electrodeselectrode where the core is composed of graphite while the exterior is a self-

baking carbon paste (which is a “Søderberg paste”)
3.1514
---------------------- Page: 11 ----------------------
pre-baked electrodes
the prebaked electrode

carbonaceous paste (a mixing of coal tar pitch with a dry carbonaceous aggregate) is baked so as to

carbonize coal tar pitch in order to form a solid pitch coke binder phase

Note 1 to entry: A carbonaceous paste is a mixing of coal tar pitch with a dry carbonaceous aggregate.

4 Symbols and abbreviated terms

For the purposes of this document, the following symbols and abbreviations apply.

AF Alternative fuels
CO carbon monoxide
CO2 carbon dioxide
EF Emission factor
FA Ferro-alloys
FABP Ferro-alloys and related by-products
GHG Greenhouse gases
GJ Giga Joule
IPCC Intergovernmental Panel on Climate Change
KPI Key Performance Indicator
LHV Lower heat value (synonym for net calorific value)
3 3
Nm normal m (at 0 °C and at a pressure of 1 atmosphere)
MIC Mineral components
SEAF Submerged electric arc furnace
TC Total Carbon (the sum of TOC and TIC)
TIC Total Inorganic Carbon
TOC Total Organic Carbon
t tonne (1,000 kg)
UNFCCC United Nations Framework Convention on Climate Change
5 Determination of GHGs –— Principles
5.1 Introduction

This document shall be used in conjunction with ISO 19694-1:2021 which contains generic, overall

requirements, definitions and rules applicable to the determination of GHG emissions for all energy-

intensive sectors, provides common methodological issues and specifies the details for applying the

rules. The application of this document to the sector-specific standards ensures accuracy, precision and

reproducibility of the results and is for this reason a normative reference standard.

5.15.2 General

The determination of CO emissions can be in principle done either through calculation (mass balance

method) or through stack emission measurement.
---------------------- Page: 12 ----------------------

The methodology described in this standarddocument for GHG emissions determination is based on the

mass balance method (7.1)).

CO2 is the only GHG relevant for the ferro-alloys industry. The emissions of CH4 and of N2O are

extremely low. Therefore, the they are both neglected in the calculation of the carbon emissions.

It has been demonstrated that The measurements of the concentrations of CH and N O arehave been

4 2

demonstrated to be near or below the detection limits during the field tests performed to develop this

[87]
standarddocument with independent laboratories .
5.25.3 Determination based on mass balance

In installations where carbon stemming from input materials used remains in the products or other

outputs of the production, e.g.for example, for the reduction of metal ores, a mass balance approach is

applied. In installations where this is not the case, combustion emissions and process emissions are

calculated separately.

Emissions from source streams are calculated from input or production data, obtained by means of

measurement systems, and additional parameters from laboratory analyses including calorific factor,

carbon content and biomass content. Standard factors maycan also be used; references to these factors

are provided in the General Aspects Standard (see normative references).ISO 19694-1:2021.

5.35.4 Use of waste gas/heat recovery

Direct GHG emissions related to waste gas and heat recovery will beare reported as scope 1direct GHG

emissions. Waste gas including CO and CO2 can be subtracted from the direct emission, when exported

outside the boundaries of the location, as a negative carbon flow in the mass balance (for examplee.g.

when exporting waste gas to another installation).
6 Boundaries
6.1 General

Drawing appropriate boundaries is one of the key tasks in an emissions inventory process.

6.2 Operational boundaries

Operational boundaries refer to the types of sources covered by an inventory. A key distinction is

between direct and indirect emissions:

a) direct emissions ([see ISO 14064-1:2018, 5.2.4 a))] are emissions from sources that are owned or

controlled by the reporting company. For example, emissions from smelting are direct emissions of

the company owning (or controlling) the furnace.

b) indirect emissions ([see ISO 14064-1:2018, 5.2.4 b -) to f))] are emissions that result as a

consequence of the activities of the reporting company but occur at sources owned or controlled by

another company. For example, emissions from the generation of grid electricity consumed by a

ferro-alloy company will qualify as indirect.

Chapter 7 of this standardClause 7 provides detailed guidance on the different sources of direct

emissions occurring in ferro-alloys plants. Indirect emissions are addressed in Chapter Clause 8.

Companies shall use the operational boundaries outlined in Table 2 and the relevant process steps in

Table 3, for the determination of the GHG emissions for the smelting/carbo-thermic reduction

operations part of the ferro-alloy plant. Any deviation from these boundaries shall be reported and

explained.
Table 2 — Operational boundaries
---------------------- Page: 13 ----------------------
Included within boundaries Excluded
Smelting (carbo-thermic reduction)): Mobile transport
Electrodes
— electrodes
— reducing agents
— non-furnace fuels
Electricity consumption for whole production Room heating / cooling (negligible)
process
Mobile transport in plant
Onsite power production: waste heat recovery
Stock inventories carbon materials —
Table 3 — Process steps
Process step Scope Inclusion? GHG emission category
ISO 14064--1 (:2018, 5.2.4
Smelting Scope 1 Yes a
Electricity consumption for Scope 2 Yes b
whole production process
Onsite power production Scope 1 Yes a
Waste heat recovery Scope 1 Yes a
Room heating / cooling Scope 1 Yes, but negligible a
Stock changes Scope 1 Yes a
6.3 Organizational boundaries

The major source of GHG emissions in the ferroalloys sector is the process-related emissions from the

submerged electric arc furnaces operations, the reduction of the metallic oxides and the consumption of

the electrodes during the process. There are practically no fuel related process emissions and heat is a

negligible input factor in the production. The operational boundaries for this standarddocument GHG

emissions cover only the smelting/carbo-thermic reduction operations considered as core activities and

the related auxiliaries.
7 Direct emissions and their determination
7.1 General

Direct emissions are emissions from sources of the respective plant. In ferro-alloys plants, direct GHG

emissions maycan result from the following sources:
a) CO2 emissions from reducing agents and electrode use in the smelting process,

b) raw materials (e.g. decomposition of limestone, dolomite, and carbon containing metal ores and

concentrates),

c) combustion of conventional fuels (e.g. natural gas, coal and coke, or fuel oil), and

d) combustion of biomass fuels.
---------------------- Page: 14 ----------------------

In installations where carbon stemming from fuels or input materials used at this installation remains

...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 19694-6
ISO/TC 146/SC 1
Stationary source emissions —
Secretariat: BIS
Determination of greenhouse gas
Voting begins on:
2022-10-07 emissions in energy-intensive
industries —
Voting terminates on:
2022-12-02
Part 6:
Ferroalloys and silicon industry
Émissions de sources fixes — Détermination des émissions des gaz à
effet de serre dans les industries à forte intensité énergétique —
Partie 6: Industrie des ferro-alliages et du silicium
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 19694-6:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022
---------------------- Page: 1 ----------------------
ISO/FDIS 19694-6:2022(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 19694-6
ISO/TC 146/SC 1
Stationary source emissions —
Secretariat: BIS
Determination of greenhouse gas
Voting begins on:
2022-10-07 emissions in energy-intensive
industries —
Voting terminates on:
2022-12-02
Part 6:
Ferroalloys and silicon industry
Émissions de sources fixes — Détermination des émissions des gaz à
effet de serre dans les industries à forte intensité énergétique —
Partie 6: Industrie des ferro-alliages et du silicium
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
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DOCUMENTATION.
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IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 19694-6:2022(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
© ISO 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022
---------------------- Page: 2 ----------------------
ISO/FDIS 19694-6:2022(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 S c op e ................................................................................................................................................................................................................................. 1

2 Nor m at i ve r ef er enc e s ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 S ymbols and abbreviated terms..........................................................................................................................................................3

5 D etermination of GHGs — Principles ............................................................................................................................................. 3

5 .1 I nt r o duc t ion .............................................................................................................................................................................................. 3

5.2 General ........................................................................................................................................................................................................... 4

5.3 D etermination based on mass balance ............................................................................................................................. 4

5.4 U se of waste gas/heat recovery .............................................................................................................................................. 4

6 B ou nd a r ie s ................................................................................................................................................................................................................. 4

6 .1 G ener a l ........................................................................................................................................................................................................... 4

6 . 2 O p er at ion a l b ou nd a r ie s ........................................................................................................................................... ....................... 4

6 . 3 O r g a n i z at ion a l b ou nd a r ie s .......................................................................................................................................................... 5

7 D irect emissions and their determination............................................................................................................................... 5

7.1 G ener a l ........................................................................................................................................................................................................... 5

7.2 M ass balance approach ................................................................................................................................................................... 6

7. 2 .1 G ener ic appr o ac h ............................................................................................................................................................... 6

7. 2 . 2 S a mpl in g .................................................................................................................................................................................... 7

7. 2 . 3 A lt er n at e appr o ac h........................................................................................................................................................... 7

7. 3 P r o c e s s em i s s ion s ................................................................................................................................................................................ 9

7. 3 .1 O ver v iew ................................................................................................................................................................................... 9

7. 3 . 2 Me t ho d s ...................................................................................................................................................................................... 9

7.4 C ombu s t ion em i s s ion s .................................................................................................................................................................. 10

7.4 .1 O ver v iew ................................................................................................................................................................................ 10

7.4 . 2 Me t ho d s ................................................................................................................................................................................... 10

7.4.3 Calculation of the quantity of fuel .................................................................................................................... 11

7.4.4 D etermination of the lower calorific value and the emission factor .................................12

7.4.5 D etermination of the oxidation factor .........................................................................................................12

7.5 Combustion of biomass fuels ..................................................................................................................................................12

8 I ndi r e c t emi s s ions ...........................................................................................................................................................................................12

8 .1 G ener a l ........................................................................................................................................................................................................12

8 . 2 CO from external electricity production ....................................................................................................................12

8 . 2 .1 G ener a l .....................................................................................................................................................................................12

8.2.2 G HG from heat transfer .............................................................................................................................................13

9 B aselines, acquisitions and disinvestments ........................................................................................................................13

10 R ep or t i n g ..................................................................................................................................................................................................................13

10 .1 G ener a l ........................................................................................................................................................................................................13

10 . 2 R epor t i ng per io d s ............................................................................................................................................................................. 14

10 . 3 Per f or m a nc e i nd ic at or s ............................................................................................................................................................... 14

10.3.1 General ..................................................................................................................................................................................... 14

10.3.2 Denominator for specific, unit-based emissions ................................................................................. 14

10.3.3 Denominator for other ratio indicators ...................................................................................................... 15

10.3.4 Key performance indicators .................................................................................................................................. 15

10.3.5 Recovery of waste gas and waste heat ........................................................................................................ 15

11 Uncertainty of GHG inventories ........................................................................................................................................................15

11.1 I ntroduction to uncertainty assessment ...................................................................................................................... 15

11.1.1 B a s ic c on s ider at ion s .................................................................................................................................................... 15

11.1.2 Materiality thresholds ................................................................................................................................................ 17

iii
© ISO 2022 – All rights reserved
---------------------- Page: 3 ----------------------
ISO/FDIS 19694-6:2022(E)

11.2 U ncertainty of activity data ..................................................................................................................................................... 17

11.2.1 Measuring instruments for the determination of fuel and material

quantities ............................................................................................................................................................................... 17

11.2.2 Aggregated uncertainties in case of mass balances ........................................................................ 17

11.3 U ncertainties of fuel and material parameters ...................................................................................................... 17

11.4 E valuation of the overall uncertainty of an GHG inventory ........................................................................ 18

Annex A (normative) Tier 1 emission factors .........................................................................................................................................19

Annex B (normative) Minimum frequency of analyses.................................................................................................................21

Annex C (normative) Country-wise emission factors for electricity ..............................................................................22

Bibliography .............................................................................................................................................................................................................................26

© ISO 2022 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/FDIS 19694-6:2022(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,

Stationary source emissions.
A list of all parts in the ISO 19694 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
---------------------- Page: 5 ----------------------
ISO/FDIS 19694-6:2022(E)
Introduction
0.1 Overview of the ferro-alloy manufacturing process

Ferroalloy production involves a metallurgical reduction process that results in significant carbon

dioxide emissions. These emissions are the results of a carbothermic reaction which is intrinsic to

the process. In ferroalloy production, ore, carbon materials and slag forming materials are mixed and

heated to high temperatures for smelting.

Smelting in an electric arc furnace is accomplished by conversion of electrical energy to heat. An

alternating current applied to the electrodes creates current to flow through the charge between the

electrode tips. The heat is produced by the electric arcs and by the resistance in the charge materials.

Emissions from the smelting process are therefore not to combustion emissions. The furnaces can be

open, semi-closed or closed. Submerged electric arc furnaces with graphite electrodes or self-baking

Søderberg electrodes are used (see Figure 1).

The reduction process is the main source of direct CO emissions. Other CO sources include direct

2 2

emissions from calcination of calcium, magnesium and other carbonates (e.g. limestone) in some

processes and from non-smelting fuels (e.g. dryers for ladles and refractory linings), room heating and

indirect emissions from, for example, external power production.
Figure 1 — Submerged electric arc furnace
0.2 CO from the smelting of raw materials

In the smelting process, CO is released due to the carbothermic reduction of the metallic oxides

occurring with the consumption of both carbonaceous reductants and carbon-based electrodes. The

carbon in the reductants reacts with oxygen from the metal oxides to form CO and then CO (in different

ways depending on the process), and the ores are reduced to molten base metals. For calculation the

assumption is that all CO is assumed to be converted in the furnace to CO .
© ISO 2022 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/FDIS 19694-6:2022(E)

The reductant carbon is used in the form of coke, coal, pet coke, anthracite, charcoal and wood chips.

The first four are fossil-based and the charcoal and wood chips are bio-carbon.

In the carbothermic process, only the fixed carbon content is used as a reducing agent, which means

that volatile matter, ashes and moisture mostly leave the furnace with the off-gas and slag.

The nature of reducing agents, price and electrodes depends on the localization of the plant, the raw

material availability and it is presented in Table 1. It is variable from one site to another and from one

year to another and also from one ferro-alloy to another.

Table 1 — Type of reducing agents and electrodes used in the electrometallurgy sector

Reducing agents Electrodes
Crude petroleum coke Graphite electrode
Calcinated petroleum coke Prebaked electrodes
Coal coke Søderberg paste
Coke from coal Composite electrode
Wood —
Calcinated wood —
Charcoal —
Graphite powder —
Anthracite —

CO emissions are estimated with and calculated from the consumption of the reducing agents and

electrodes, their carbon content and the carbon content of the final products.

NOTE The basic calculation methods used in this document are compatible with the 2006 IPCC Guidelines

[1]

for National Greenhouse Gas Inventories issued by the Intergovernmental Panel on Climate Change (IPCC) .

Ores and reducing agent react to form ferro-alloys or metal, CO and dust and other by-product (i.e.

slags); amount of carbon can be found in the products

Default emission factors suggested in these documents are used, except where more recent, industry-

specific data has become available.
vii
© ISO 2022 – All rights reserved
---------------------- Page: 7 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 19694-6:2022(E)
Stationary source emissions — Determination of
greenhouse gas emissions in energy-intensive industries —
Part 6:
Ferroalloys and silicon industry
1 S cope

This document provides a harmonized methodology for calculating GHG emissions from the ferro-

alloys industry based on the mass balance approach. This document also provides key performance

indicators over time for ferro-alloys plants. This document covers the following direct and indirect

sources of GHG:

— direct GHG emissions [see ISO 14064-1:2018, 5.2.4 a)] from sources that are owned or controlled by

the company, such as emissions resulting from the following sources:
— smelting (reduction) process;
— decomposition of carbonates inside the furnace;

— auxiliaries operation related to the smelting operation (i.e. aggregates, drying processes,

heating of ladles, etc.);

— indirect GHG emissions [see ISO 14064-1:2018, 5.2.4 b)] from the generation of purchased electricity

consumed in the company’s owned or controlled equipment.
2 Normat ive references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 14064-1:2018, Greenhouse gases — Part 1: Specification with guidance at the organization level for

quantification and reporting of greenhouse gas emissions and removals

ISO 17025, 2005, General requirements for the competence of testing and calibration laboratories

ISO 19694-1:2021, Stationary source emissions — Determination of greenhouse gas emissions in energy-

intensive industries — Part 1: General aspects
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 19694-1:2021 and the

following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

For the purposes of this document, the terms and definitions in and the following apply.

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ISO/FDIS 19694-6:2022(E)

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
auxiliary
equipment consuming electricity/power related to the smelting (3.5) process

EXAMPLE Fans, pumps, gas abatement systems (filter bags, venture scrubbers, etc.).

3.2
silica fume

amorphous silicon dioxide particles from the volatilization and vaporization of furnace feed materials

in the manufacture of ferrosilicon and silicon (3.4)

Note 1 to entry: The process off-gas that contains silica fumes beings cleaned in a baghouse using fabric filters of

the open or semi-closed SEAF (3.8).
3.3
ferro-alloy

alloy of iron and one or more metals such as silicon (3.4), manganese, chromium, molybdenum,

vanadium and tungsten
3.4
silicon

metalloid produced by carbo-thermic reduction of quartz in an electric submerged arc furnace

3.5
smelting

industrial process where one or more ores or ore concentrates are heated and reduced (i.e. chemically

modified) by, for example, aluminino-carbo-silico thermic reduction, to manufacture and mix the

metals in one step
Note 1 to entry: Examples of smelted alloys are ferro-alloys (3.3).
3.6
gross GHG emission

absolute fossil direct GHG emission excluding GHG emissions from on-site power production

3.7
absolute gross GHG emission

total direct emission of GHGs within the boundaries excluding GHG emissions from biogenic CO from

biomass (i.e. wood chips and charcoal)
3.8
submerged electric arc furnace
SEAF

electric arc-heating furnace in which the arcs are completely submerged under the charge

Note 1 to entry: The arc forms between the electrode [graphite electrodes or self-baking Søderberg electrodes

(3.12)] and metal surface or bottom lining. The heat being produced by the electric arcs and by the resistance in

the charge materials initiates the reduction process. The furnaces can be open, semi-closed or closed, which can

depend upon the ferro-alloy (3.3) to be produced.
3.9
biomass fuel
fuel with only biogenic carbon
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ISO/FDIS 19694-6:2022(E)
3.10
petroleum coke
petcoke
carbon-based solid fuel derived from oil refineries
3.11
sinter
sintering
process to form a coherent mass by heating without melting
3.12
Søderberg electrode

continuously self-baking carbon electrode used in electro-metallurgical furnaces for production of

ferroalloys and silicon (3.4)

Note 1 to entry: The “Søderberg paste” is a preparation of coal tar pitch and carbonaceous dry aggregate.

3.13
composite electrode

electrode where the core is composed of graphite while the exterior is a self-baking carbon paste (which

is a “Søderberg paste”)
3.14
prebaked electrode

carbonaceous paste baked so as to carbonize coal tar pitch in order to form a solid pitch coke binder

phaseNote 1 to entry: A carbonaceous paste is a mixing of coal tar pitch with a dry carbonaceous

aggregate.
4 S ymbols and abbreviated terms

For the purposes of this document, the following symbols and abbreviations apply.

CO carbon monoxide
CO carbon dioxide
EF Emission factor
FA Ferro-alloys
GHG Greenhouse gases
IPCC Intergovernmental Panel on Climate Change
KPI Key Performance Indicator
SEAF Submerged electric arc furnace
UNFCCC United Nations Framework Convention on Climate Change
5 De termination of GHGs — Principles
5.1 Introduction

This document shall be used in conjunction with ISO 19694-1:2021 which contains generic, overall

requirements, definitions and rules applicable to the determination of GHG emissions for all energy-

intensive sectors, provides common methodological issues and specifies the details for applying the

rules. The application of this document to the sector-specific standards ensures accuracy, precision and

reproducibility of the results and is for this reason a normative reference standard.

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ISO/FDIS 19694-6:2022(E)
5.2 General

The determination of CO emissions can be in principle done either through calculation (mass balance

method) or through stack emission measurement.

The methodology described in this document for GHG emissions determination is based on the mass

balance method (7.1).

CO is the only GHG relevant for the ferro-alloys industry. The emissions of CH and of N O are extremely

2 4 2
low. Therefore, they are both neglected in the calculation of carbon emissions.

The measurements of the concentrations of CH and N O have been demonstrated to be near or below

4 2

the detection limits during the field tests performed to develop this document with independent

[7]
laboratories .
5.3 Det ermination based on mass balance

In installations where carbon stemming from input materials used remains in the products or other

outputs of the production, for example, for the reduction of metal ores, a mass balance approach is

applied. In installations where this is not the case, combustion emissions and process emissions are

calculated separately.

Emissions from source streams are calculated from input or production data, obtained by means of

measurement systems and additional parameters from laboratory analyses including calorific factor,

carbon content and biomass content. Standard factors can also be used; references to these factors are

provided in ISO 19694-1:2021.
5.4 Use of w aste gas/heat recovery

GHG emissions related to waste gas and heat recovery are reported as direct GHG emissions. Waste

gas including CO and CO can be subtracted from the direct emission, when exported outside the

boundaries of the location, as a negative carbon flow in the mass balance (e.g. when exporting waste

gas to another installation).
6 Bo undaries
6.1 General

Drawing appropriate boundaries is one of the key tasks in an emissions inventory process.

6.2 Operational bound aries

Operational boundaries refer to the types of sources covered by an inventory. A key distinction is

between direct and indirect emissions:

a) direct emissions [see ISO 14064-1:2018, 5.2.4 a)] are emissions from sources that are owned or

controlled by the reporting company. For example, emissions from smelting are direct emissions of

the company owning (or controlling) the furnace.

b) indirect emissions [see ISO 14064-1:2018, 5.2.4 b) to f)] are emissions that result as a consequence

of the activities of the reporting company but occur at sources owned or controlled by another

company. For example, emissions from the generation of grid electricity consumed by a ferro-alloy

company qualify as indirect.

Clause 7 provides detailed guidance on the different sources of direct emissions occurring in ferro-

alloys plants. Indirect emissions are addressed in Clause 8.
Companies shall use the oper
...