ASTM E2295-03(2008)e1

Standard Practice for Fire Assay Silver Corrections in Analysis of Metal Bearing Ores, Concentrates, and Related Metallurgical Materials by Silver Determination in Slags and Cupels

SIGNIFICANCE AND USE
These methods are primarily intended to be used for the determination of silver correction in the fire assay silver determination. Silver assays are determined by fire assay for the purpose of metallurgical exchange between seller and buyer.
It is assumed that all who use this method will be trained analysts capable of performing skillfully and safely. It is expected that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described in Guide E 882.
SCOPE
1.1 This practice covers the determination of silver corrections for fire assay of metal bearing ores, concentrates and related metallurgical materials using the spent slags and cupels from the fire assay process, by gravimetry and atomic absorption spectrophotometry.
1.2 The test methods appear in the following order:
Sections Gravimetric Method10–11 Atomic Absorption Method12–13
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (See Practices E 50 and ISO Guide 35:1989.)

General Information

• Status: Historical
• Publication Date: 14-Dec-2008
• ICS: 73.060.01 - Metalliferous minerals in general
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.02 - Ores, Concentrates, and Related Metallurgical Materials

Relations

• Replaces: ASTM E2295-03 - Standard Practice for Fire Assay Silver Corrections in Analysis of Metal Bearing Ores, Concentrates, and Related Metallurgical Materials by Silver Determination in Slags and Cupels
• Effective Date: 15-Dec-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: E2295 − 03 (Reapproved2008)
Standard Practice for
Fire Assay Silver Corrections in Analysis of Metal Bearing
Ores, Concentrates, and Related Metallurgical Materials by
Silver Determination in Slags and Cupels
This standard is issued under the fixed designation E2295; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Editorial and warning note changes were made throughout in December 2008.
1. Scope Metals, Ores, and Related Materials
E882 Guide for Accountability and Quality Control in the
1.1 This practice covers the determination of silver correc-
Chemical Analysis Laboratory
tions for fire assay of metal bearing ores, concentrates and
E1024 Guide for Chemical Analysis of Metals and Metal
related metallurgical materials using the spent slags and cupels
Bearing Ores by Flame Atomic Absorption Spectropho-
from the fire assay process, by gravimetry and atomic absorp-
tometry (Withdrawn 2004)
tion spectrophotometry.
E1335 Test Methods for Determination of Gold in Bullion
1.2 The test methods appear in the following order:
by Fire Assay Cupellation Analysis
Sections
2.2 ISO Documents:
Gravimetric Method 10–11
ISO Guide 35:1989 Certification of Reference Materials—
Atomic Absorption Method 12–13
General and Statistical Principles
1.3 The values stated in SI units are to be regarded as
ISO 10378:1994 Copper Sulfide Concentrates—
standard. No other units of measurement are included in this
Determination of Gold and Silver Contents—Fire Assay
standard.
Gravimetric and Atomic Absorption Spectrometric
1.4 This standard does not purport to address all of the
Method
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3. Terminology
priate safety and health practices and determine the applica-
3.1 Definitions—For definitions of terms used in this
bility of regulatory limitations prior to use. (See Practices E50
practice, refer to Terminology E135.
and ISO Guide 35:1989.)
4. Summary of Practice
2. Referenced Documents
4.1 In the process of fire assay fusion slags and cupels are
2.1 ASTM Standards:
collected, retreated and silver is determined in them to provide
D1193 Specification for Reagent Water
a correction value for the fire assay determination of silver (see
E29 Practice for Using Significant Digits in Test Data to
GuideE1024,TestMethodsE1335,ISO 10378:1994,Bugbee,
Determine Conformance with Specifications
and Smith ).
E50 Practices for Apparatus, Reagents, and Safety Consid-
erations for Chemical Analysis of Metals, Ores, and
5. Significance and Use
Related Materials
5.1 These methods are primarily intended to be used for the
E135 Terminology Relating to Analytical Chemistry for
determination of silver correction in the fire assay silver
This practice is under the jurisdiction of ASTM Committee E01 on Analytical
Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of The last approved version of this historical standard is referenced on
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials. www.astm.org.
Current edition approved Dec. 15, 2008. Published January 2009. Originally Available from International Organization for Standardization (ISO), 1, ch. de
approved in 2003. Last previous edition approved in 2003 as E2295 – 03. DOI: la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
10.1520/E2295-03R08E01. www.iso.ch.
2 5
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Bugbee, E. E., A Textbook of Fire Assaying, Third Ed., John Wiley and Sons,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Inc., Hoboken, NJ, 1946.
Standards volume information, refer to the standard’s Document Summary page on Smith, E. A., The Sampling and Assay of the Precious Metals, Second Ed.,
the ASTM website. Charles Griffin and Co., Ltd., 1947.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E2295 − 03 (2008)
determination. Silver assays are determined by fire assay for 9. Sampling and Sample Preparation
the purpose of metallurgical exchange between seller and
9.1 Weigh the fire assay slags and cupels from the duplicate
buyer.
fusion and cupellation processes for each test sample on a
5.2 Itisassumedthatallwhousethismethodwillbetrained balance to 0.01 g. Record weight.
analysts capable of performing skillfully and safely. It is
9.2 Place the weighed slags and cupels into a ring grinder
expected that work will be performed in a properly equipped
and pulverize for about 20 s. This should reduce the material
laboratory under appropriate quality control practices such as
to pass a 150-µm sieve. This is the retreatment sample that
those described in Guide E882.
corresponds to the duplicate test sample.
NOTE 1—Longer grinding may cause caking of the ground material.
6. Apparatus
Clean the ring grinder by grinding silica sand between each retreatment
sample.
6.1 Analytical Balance, capable of weighing to 0.01 g.
GRAVIMETRIC SILVER CORRECTION METHOD
6.2 Analytical Balance, capable of weighing to 0.001 mg.
6.3 Assay Furnace, capable of temperatures up to 1100 °C,
10. Procedure
accurate to 6 5 °C.
10.1 To the duplicate crucibles saved from the fire assay
6.4 Atomic Absorption Spectrophotometry, AAS.
fusion of each test sample, add the following flux.
6.5 Ring Grinder, 250 g capacity.
Crucible Fire Assay Flux
1. Litharge—50 g
2. Sodium Carbonate—50 g
7. Reagents and Materials
3. Silica—50 g
7.1 Purity of Reagents—Reagent grade chemicals shall be 4. Borax—50 g
5. Flour—Usually 4 g add or subtract to produce an approximately
used in all tests. Unless otherwise indicated, it is intended that
30 g lead fire assay button
all reagents conform to the specifications of the Committee on
10.2 Weigh two portions of the retreatment sample into the
Analytical Reagents of the American Chemical Society where
pre-fluxed crucibles and record the weights.
such specifications are available. Other grades may be used,
Sample A = 14.583 g or ⁄2 AT
provided it is first ascertained that the reagent is of sufficiently
Sample B = 29.167 g or 1 AT
high purity to permit its use without lessening the accuracy of
NOTE 2—AT = Assay Ton, a fire assay weight system.
the determination.
10.3 Mix retreatment samples and flux together in the
7.2 Purity of Water—Unless otherwise indicated, references
crucibles.
to water shall be understood to mean reagent water as defined
by Type I of Specification D1193.
...

This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation:E2295–03 Designation:E2295–03(Reapproved2008)
Standard Practice for
Fire Assay Silver Corrections in Analysis of Metal Bearing
Ores, Concentrates, and Related Metallurgical Materials by
Silver Determination in Slags and Cupels
This standard is issued under the fixed designation E 2295; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Editorial and warning note changes were made throughout in December 2008.
1. Scope
1.1 This practice covers the determination of silver corrections for fire assay of metal bearing ores, concentrates and related
metallurgical materials using the spent slags and cupels from the fire assay process, by gravimetry and atomic absorption
spectrophotometry.
1.2 The test methods appear in the following order:
Sections
Gravimetric Method 10-11
Gravimetric Method 10–11
Atomic Absorption Method 12-13
Atomic Absorption Method 12–13
1.3
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. (See Practices E 50 and ISO Guide35: 1989.) and ISO Guide 35:1989.)
2. Referenced Documents
2.1 ASTM Standards:
D 1193 Specification for Reagent Water
E29 Practice for Using Significant Digits in Test Data to Determine Conformance Withwith Specifications
E50 Practices for Apparatus, Reagents, and Safety Precautions for Chemical Analysis of Metals Practices for Apparatus,
Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
E 135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E 882 Guide for Accountability and Quality Control in the Chemical Analysis Laboratory
E 1024 Guide for Chemical Analysis of Metals and Metal Bearing Ores by Flame Atomic Absorption Spectrophotometry
E 1335 Test Methods for Determination of Gold in Bullion by Fire Assay Cupellation Analysis
2.2 Other Documents: ISO Documents:
ISO Guide 35-:1989 Certification of Reference Materials-—General and Statistical Principles
ISO 10378:1994Copper Sulfide Concentrates-Determination of Gold and Silver Contents-Fire Assay Gravimetric and Atomic
Absorption Spectrometric Method. Bugbee, Edward, Textbook of Fire Assaying; Smith, E.A., The Sampling and Assay of
Precious Metals Copper Sulfide Concentrates—Determination of Gold and Silver Contents—Fire Assay Gravimetric and
Atomic Absorption Spectrometric Method
This practice is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores and Related Materials and is the direct responsibility of
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials .
Current edition approved June 10, 2003. Published July 2003.
This practice is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility of
Subcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.
Current edition approved Dec. 15, 2008. Published January 2009. Originally approved in 2003. Last previous edition approved in 2003 as E 2295 – 03.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
, Vol 11.01.volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book of ASTM Standards, Vol 14.02.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
´1
E2295–03 (2008)
3. Terminology
3.1 Definitions—For definitions of terms used in this Practice,practice, refer to Terminology E 135.
4. Summary of Practice
4.1 In the process of fire assay fusion slags and cupels are collected, retreated and silver is determined in them to provide a
correction value for the fire assay determination of silver (see Guide E 1024, Test Method E1335, ISO 10378, Bugbee, Smith). ,
4 5
Test Methods E 1335, ISO 10378:1994, Bugbee, and Smith ).
5. Significance and Use
5.1 These methods are primarily intended to be used for the determination of silver correction in the fire assay silver
determination. Silver assays are determined by fire assay for the purpose of metallurgical exchange between seller and buyer.
5.2 It is assumed that all who use this method will be trained analysts capable of performing skillfully and safely. It is expected
that work will be performed in a properly equipped laboratory under appropriate quality control practices such as those described
in Guide E 882.
6. Apparatus
6.1 Analytical Balance, capable of weighing to 0.01 g.
6.2 Analytical Balance, capable of weighing to 0.001 mg.
6.3 Assay Furnace, capable of temperatures up to 1100 °C, accurate to 6 5 °C.
6.4 Atomic Absorption Spectrophotometry, AAS.
6.5 Ring Grinder, 250 g capacity.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity
to permit its use without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by
Type I of Specification D 1193.
7.3 Borax, sodium tetraborate (Na B O ), technical grade.
2 4 7
7.4 Ammonium Chloride Solution (NH Cl 250g/L)—Add 250 g of ammonium chloride to 500 mLof water in a 1-Lvolumetric
flask. Dilute to the mark and mix.
7.5 Crucibles, standard fire assay.
7.6 Cupels, magnesite (MgCO ) or bone ash.
7.7 Flour, common baking grade.
7.8 Litharge, PbO-tech grade silver free. Litharge (PbO), technical grade, silver free.
7.9 Silica Sand (SiO ), technical grade.
7.10 Sodium Carbonate (Na CO ), technical grade.
2 3
8. Hazards
8.1 For precautions to be observed in this practice, refer to Practice E 50.
8.2 All precautions and safe laboratory operating procedures should be followed when using perchloric acid. HClO .
9. Sampling and Sample Preparation
9.1 Weigh the fire assay slags and cupels from the duplicate fusion and cupellation processes for each test sample on a balance
to 0.01 g. Record weight.
9.2 Place the weighed slags and cupels into a ring grinder and pulverize for about 20 s. This should reduce the material to pass
a No. 100 (150-µm)150-µm sieve. This is the retreatment sample that corresponds to the duplicate test sample.
NOTE 1—Longer grinding may cause cak
...