Characterization of waste - Static test for determination of acid potential and neutralisation potential of sulfidic waste

This European standard specifies methods to determine the potential of sulfide bearing materials for the formation of acidic drainage. Specified are methods for determining both the acid potential (AP) and the neutralisation potential (NP) of the material. From these results the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) are calculated. This European standard is applicable to all sulfide bearing wastes from the extractive industries excluding wastes which will have pH < 2 in the initial step of the procedure described in 8.2.3.

Charakterisierung von Abfällen - Statische Prüfung zur Bestimmung des Säurebildungspotenzials und des Neutralisationspotenzials von sulfidhaltigen Abfällen

Diese Europäische Norm legt Verfahren zur Bestimmung des Potenzials von sulfidhaltigen Materialien zur
Säurebildung fest. Festgelegt werden Verfahren zur Bestimmung sowohl des Säurebildungspotenzials
(en: acid potential, AP) als auch des Neutralisationspotenzials (en: neutralisation potential, NP) des Materials.
Aus diesen Ergebnissen werden das Nettoneutralisationspotenzial (en: net neutralisation potential, NNP) und
der Pufferungsquotient (en: neutralisation potential ratio, NPR) berechnet.
Diese Europäische Norm ist auf sämtliche sulfidhaltigen Abfälle aus der mineralgewinnenden Industrie
anwendbar, mit Ausnahme von Abfällen, deren pH-Wert beim ersten Schritt des in 8.2.3 beschriebenen
Verfahrens geringer als 2 ist.

Caractérisation des déchets - Essai statique pour la détermination du potentiel de génération d'acide et du potentiel de neutralisation des déchets sulfurés

La présente Norme européenne spécifie des méthodes permettant de déterminer le potentiel des matériaux
sulfurés à former des eaux de drainage acides. Les méthodes spécifiées permettent de déterminer à la fois le
potentiel de génération d'acide (AP) et le potentiel de neutralisation (NP) du matériau. A partir de ces
résultats, le potentiel de neutralisation net (NNP) et le rapport de potentiel de neutralisation (NPR) sont
calculés.
La présente Norme européenne est applicable à tous les déchets sulfurés de l'industrie extractive, à
l'exclusion des déchets qui auront un pH inférieur à 2, lors de l'étape initiale du mode opératoire décrit en
8.2.3.

Karakterizacija odpadkov - Statični preskus za določevanje kislinske in nevtralizacijske kapacitete odpadkov, ki vsebujejo sulfid

Ta evropski standard določa metode za določevanje kapacitete materialov, ki vsebujejo sulfid, za tvorbo kisle drenaže. Opredeljene so metode za določevanje kislinske (AP) in nevtralizacijske kapacitete (NP) materiala. Iz teh rezultatov se računa neto nevtralizacijska kapaciteta (NNP) in razmerje nevtralizacijske kapacitete (NPR). Ta evropski standard se uporablja za vse odpadke ekstraktivne industrije, ki vsebujejo sulfid, razen odpadkov, katerih pH v prvi fazi postopka, opisanega v 8.2.3, znaša < 2.

General Information

Status
Published
Public Enquiry End Date
19-Feb-2009
Publication Date
15-Jan-2012
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
27-Dec-2011
Due Date
02-Mar-2012
Completion Date
16-Jan-2012

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Charakterisierung von Abfällen - Statische Prüfung zur Bestimmung des Säurebildungspotenzials und des Neutralisationspotenzials von sulfidhaltigen AbfällenCaractérisation des déchets - Essai statique pour la détermination du potentiel de génération d'acide et du potentiel de neutralisation des déchets sulfurésCharacterization of waste - Static test for determination of acid potential and neutralisation potential of sulfidic waste13.030.10Trdni odpadkiSolid wastesICS:Ta slovenski standard je istoveten z:EN 15875:2011SIST EN 15875:2012en,fr,de01-februar-2012SIST EN 15875:2012SLOVENSKI
STANDARD



SIST EN 15875:2012



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 15875
October 2011 ICS 13.030.10 English Version
Characterization of waste - Static test for determination of acid potential and neutralisation potential of sulfidic waste
Caractérisation des déchets - Essai statique pour la détermination du potentiel de génération d'acide et du potentiel de neutralisation des déchets sulfurés
Charakterisierung von Abfällen - Statische Prüfung zur Bestimmung des Säurebildungspotenzials und des Neutralisationspotenzials von sulfidhaltigen Abfällen This European Standard was approved by CEN on 17 September 2011.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15875:2011: ESIST EN 15875:2012



EN 15875:2011 (E) 2 Contents Page Foreword .3Introduction .41 Scope .52 Normative references .53 Terms and definitions .54 Symbols and abbreviations .65 Principle .76 Reagents and laboratory devices .76.1 Reagents .76.2 Laboratory devices .77 Sampling and sample preparation .77.1 Laboratory sample .77.2 Test sample .87.3 Determination of dry residue of the sample .87.4 Test portion for the determination of neutralisation potential .88 Test procedures .98.1 Determination of acid potential .98.1.1 General .98.1.2 Total sulfur content .98.1.3 Determination of sulfur species .98.1.4 Calculation .98.2 Determination of neutralisation potential . 108.2.1 General . 108.2.2 Carbonate rating . 108.2.3 Neutralisation potential . 108.2.4 Calculation . 129 Calculation of neutralisation potential ratio and net neutralisation potential . 1210 Performance characteristics . 1311 Test report . 13Annex A (informative)
Example of a data sheet for the recording of test results according to 8.2.3 . 15Annex B (informative)
Operation and uses of the test: influence of parameters . 16B.1 Sulfur determination . 16B.2 Particle size . 16B.3 Mineralogy . 16B.3.1 Sources of acidity . 16B.3.2 Neutralisation potential . 18Annex C (informative)
Speciation of sulfur compounds . 20Annex D (informative)
Explanation of formulas used . 23D.1 Acid potential . 23D.2 Carbonate rating . 23Bibliography . 25 SIST EN 15875:2012



EN 15875:2011 (E) 3 Foreword This document (EN 15875:2011) has been prepared by Technical Committee CEN/TC 292 “Characterization of waste”, the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2012, and conflicting national standards shall be withdrawn at the latest by April 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. The preparation of this document by CEN is based on a mandate by the European Commission (Mandate M/395), which assigned the development of standards on the characterization of waste from extractive industries. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 15875:2012



EN 15875:2011 (E) 4 Introduction This document has been developed primarily to support the implementation of the Directive 2006/21/EC of the European Parliament and of the council on the management of waste from the extractive industries, especially relating to technical requirements for waste characterization as sulfide bearing materials may generate sulfuric acid when subjected to weathering. Test methods for the determination of acid generation behaviour can be divided in static and kinetic tests. A static test is usually relatively fast to perform, but gives only indicative information based on total composition of the waste material. The kinetic test gives more detailed information on behaviour based on reaction rates under specified conditions. This standard only covers static testing. The application of this test method alone may not be sufficient to determine the actual potential in the field for the formation of acidic drainage as site specific conditions will affect the behaviour in the field and require a more detailed assessment.
To carry out a more precise assessment of the acid generation potential and buffering capacity mineralogical information is required. A number of special cases can be identified: e.g. presence of sulfate (e.g. gypsum), non-acid producing sulfides or carbonates with no buffering capacity. Acid neutralisation behaviour as obtained by other methods can provide additional information in circumstances of uncertainty.
SIST EN 15875:2012



EN 15875:2011 (E) 5 1 Scope This European standard specifies methods to determine the potential of sulfide bearing materials for the formation of acidic drainage. Specified are methods for determining both the acid potential (AP) and the neutralisation potential (NP) of the material. From these results the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) are calculated.
This European standard is applicable to all sulfide bearing wastes from the extractive industries excluding wastes which will have pH < 2 in the initial step of the procedure described in 8.2.3. 2 Normative references The following referenced documents are indispensable for the application 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. EN 13137:2001, Characterization of waste — Determination of total organic carbon (TOC) in waste, sludges and sediments EN 14346, Characterization of waste — Calculation of dry matter by determination of dry residue or water content EN 14582, Characterization of waste — Halogen and sulfur content — Oxygen combustion in closed systems and determination methods
EN 14899, Characterization of waste — Sampling of waste materials — Framework for the preparation and application of a Sampling Plan EN 15002, Characterization of waste — Preparation of test portions from the laboratory sample ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth ISO 15178, Soil quality — Determination of total sulfur by dry combustion ISO 16720, Soil quality — Pretreatment of samples by freeze-drying for subsequent analysis 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 laboratory sample
sample sent to or received by the laboratory 3.2 test sample sample, prepared from the laboratory sample, from which test portions are removed for testing or analysis 3.3 test portion
quantity of material of proper size, for measurement of the concentration or other properties of interest, taken from the test sample NOTE The test portion may be taken from the laboratory sample directly if no preparation of sample is required (e.g. samples of proper homogeneity, size and fineness). SIST EN 15875:2012



EN 15875:2011 (E) 6 3.4 acid potential
maximum potential acid generation from a sample assuming that all sulfur occurs as pyrite and that acidity will result from its complete oxidation
3.5 neutralisation potential
capacity of a sample to neutralise the generated acidity 3.6 carbonate rating
carbonate content of the sample used to specify the volume(s) of acid to be added during the procedure NOTE In this European standard the carbonate rating to specify the volume(s) of acid to be added during the procedure is described in 8.2.3. 3.7 net neutralisation potential difference between neutralisation potential and acid potential 3.8 neutralisation potential ratio
ratio of neutralisation potential and acid potential 4 Symbols and abbreviations AP acid potential NP neutralisation potential CR carbonate rating Md dry mass of the test portion Mw un-dried mass of the test portion md mass after drying at 105 °C mw mass before drying
Ms
molecular weight of sulfur NNP net neutralisation potential NPR
neutralisation potential ratio t = 0 time at the start of the test (after 15 min ± 5 min stirring) VA/B volume of acid or base added VA, t=0 volume of acid added at t = 0 VA, t=22h volume of acid added at t = 22 h wdr dry residue of the sample SIST EN 15875:2012



EN 15875:2011 (E) 7 5 Principle This test method consists of four steps:  Determination of total sulfur by bomb (EN 14582) or high temperature combustion (ISO 15178) and calculation of acid potential (AP). Instead of total sulfur, sulfides may be determined using techniques described in the informative Annex C.
 Determination of carbonate content by dry combustion (EN 13137:2001, method A) to give the carbonate rating (CR).  Determination of the neutralisation potential (NP) by hydrochloric acid addition to reach pH = 2 to 2,5 and back titration with sodium hydroxide to reach pH = 8,3 after reaction time of 24 h.
 Calculations of the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) based on AP and NP.
AP and NP are expressed as H+ content in mol/kg. The conversion factor is given for expression as carbonate equivalents (CaCO3) in kg/t.
6 Reagents and laboratory devices
6.1 Reagents 6.1.1 Distilled or demineralised water 6.1.2 Hydrochloric acid (analysis grade), c(HCl) = 1 mol/l
6.1.3 Sodium hydroxide (analysis grade), c(NaOH) = 0,1 mol/l 6.2 Laboratory devices 6.2.1 Analytical balance, with an accuracy of 0,05 g
6.2.2 Bottles or vessels (250 ml) made of inert material such as glass or high density polyethylene (HDPE) or polypropylene (PP) and supplied with a lid of inert material (e.g. PTFE). Rinsing is compulsory. When using magnetic bar in stirring (see 6.2.4) it is crucial to use a test vessel or bottle with flat bottom in order to guarantee good mixing.
6.2.3 Size reducing equipment, e.g. a jaw crusher, rotary swing mill, ball mill or similar device. 6.2.4 Stirring device or magnetic stirring device with magnetic bar coated with PTFE. The parts in contact with the sample and reagents shall be made of materials not affecting the outcome of the test like glass, PTFE. 6.2.5 pH meter with a measurement accuracy of at least ± 0,05 pH units. 6.2.6 Sample dividers (e.g. rotary splitter or riffle divider)
6.2.7 Sieves, conforming to the requirements of ISO 3310-1, with screen size of 0,125 mm. 7 Sampling and sample preparation 7.1 Laboratory sample Perform sampling in accordance with EN 14899 in order to obtain a representative laboratory sample.
The laboratory sample shall have a mass of at least 1 kg (dry mass). SIST EN 15875:2012



EN 15875:2011 (E) 8 NOTE The mass of the laboratory sample is dependent on its maximum particle size and homogeneity. Further information on sample masses can be obtained from EN 15002.
7.2 Test sample The test sample shall have a particle size of 95 % less than 0,125 mm. For material with larger particle sizes the following shall apply: Crush the laboratory sample to < 2 mm following the procedures given in EN 15002. Take a subsample from the crushed material by using a suitable divider (6.2.6) or by coning and quartering. The subsample of approximately 100 g is then milled to a particle size of 95 % less than 0,125 mm.
Moist material that is not possible to sieve is dried prior to sieving and/or crushing. The drying temperature shall not exceed 40 °C in order to avoid unwanted reactions. Alternatively, freeze drying according to ISO 16720 can be used. The crushed material can change upon storage due to ageing of fresh surfaces. It is therefore recommended to test the material as soon as possible after crushing. If short-term storage is needed, crushed material should be stored cold and dark. For long-term storage material should be dried (at temperatures not exceeding 40 °C) prior to storage to prevent acid generating reactions. 7.3 Determination of dry residue of the sample
The whole test sample, complying with the size criteria in 7.2 shall not be dried any further. The dry residue (wdr) of the test sample shall be determined on a separate test portion according to EN 14346.
The dry residue of the sample shall be determined at 105 °C ± 5 °C according to EN 14346. The dry residue expressed as mass fraction in percent is calculated according to Equation (1): wddr100mmw×= (1) where wdr is the dry residue of the sample expressed as mass fraction in percent; md is the mass after drying expressed in grams (g); mw is the mass of the sample after sample pretreatment as described in 7.2 and before drying expressed in grams (g).
7.4 Test portion for the determination of neutralisation potential Prepare a representative test portion in accordance with EN 15002.
Calculate the mass of the test portion Mw in grams to be used for the test in accordance with Equation (2): 100drdw×=wMM (2) where
Md is the dry mass of the test portion expressed in grams (g); Mw is the total mass of the test portion expressed in grams (g). SIST EN 15875:2012



EN 15875:2011 (E) 9 8 Test procedures 8.1 Determination of acid potential 8.1.1 General The acid potential (AP) can either be based on the determination of total sulfur or on a species analysis where sulfide sulfur is determined. Analysis of total sulfur is a well established method with a high potential of automatisation resulting in short analysis times. Total sulfur determination can therefore be regarded as a default method which is described in 8.1.2. If either through mineralogical or chemical analysis it is shown that substantial parts of total sulfur is sulfate, then a more appropriate (realistic) AP is obtained by analyzing sulfur species (see 8.1.3).
NOTE The main source for acidity is the oxidation of sulfides. Total sulfur is used as a conservative approximation of sulfide content. If a significant part of total sulfur is sulfate this will lead to a significant overestimation of AP, in which case a more realistic assessment will be achieved if the AP determination is based on sulfide content. 8.1.2 Total sulfur content Total sulfur content is determined either by bomb combustion according EN 14582 or by high temperature combustion according ISO 15178.
The bomb combustion method described in EN 14582 usually gives high recoveries when inorganic salts are analysed. However, depending on the material to be analysed, suitable pure inorganic compounds with similar sulfur binding shall be used to test recovery rates. When using high temperature combustion techniques, appropriate operating conditions of the analysis
shall be chosen, to ensure the detection of all sulphur components, including temperature stable inorganic sulphates (e.g. calcium sulfate). This can be achieved by increasing the temperature (e.g. up to 1 500 °C) or the use of tin capsules (which burn in an exothermic reaction resulting in high temperatures). Also measuring time may be increased as these stable compounds react slower. Calibration has to be made with calibrants having the same range of sulfur concentration as the material to be analysed. 8.1.3 Determination of sulfur species The main purpose of all species analyses is the determination of sulfides, mainly pyrite. This can be done either by direct determination of pyrite or by subtraction of the sulfate sulfur fraction from the total sulfur content (assuming no other sulfur species like elemental sulfur is present). The choice of direct or indirect approach depends on the mineralogical composition of the sample. There are no CEN or ISO standards for the determination of sulfur species (sulfate-, sulfide-, disulfide-, sulfur) in waste described in this standard. However, guidance is given in the informative Annex C. NOTE Some sulfides do not contribute to AP, this can only be assessed through more detailed characterisation, such as mineralogy. 8.1.4 Calculation The acid potential (AP) is calculated based on the sulfur content (either total or sulfide sulfur) as follows: NOTE 1 Calculation of acid potential assumes all sulfur to appear as pyrite a) expressed as H+ content in mol/kg (Equation (3)) S0,625APw×= (3) SIST EN 15875:2012



EN 15875:2011 (E) 10 where
0,625 is the conversion factor (taking into account the conversion of units and that 1 mol of sulfur in pyrite creates 2 moles of H+) (for further explanation see Annex D); wS is the sulfur (either total or sulfide sulfur) content as mass fraction in percent. b) expressed as carbonate equivalents (CaCO3) in kg/t (Equation (4)) S 31,25APw×= (4) where
31,25 is the conversion factor (ratio of molecular masses of calcium carbonate (100 g/mol) and sulfur (32 g/mol)) (for further explanation see Annex D); wS
is the sulfur (either total or sulfide sulfur) content as mass fraction in percent. NOTE 2 AP and NP values expressed as H+ content in mol/kg can be converted to carbonate equivalents (CaCO3) in kg/t by multiplying by 50. Likewise a AP or NP expressed in carbonate equivalents (CaCO3) in kg/t can be converted to H+ content in mol/kg by multiplying by 0,02.
8.2 Determination of neutralisation potential 8.2.1 General The amount of acid added for the test is crucial for the results obtained. Therefore, the carbonate content is determined first to give the carbonate rating. From this, the required hydrochloric acid addition is taken from Table 1. 8.2.2 Carbonate rating Determine the carbonate content following the procedure in EN 13137:2001, method A. The carbonate carbon content obtained from EN 13137:2001 (there named “inorganic carbon”) is expressed as mass fraction in percent, it is used as carbonate rating in 8.2.3 (for further explanation see Annex D). 8.2.3 Neutralisation potential Weigh test portion Mw corresponding to 2,00 g ± 0,10 g of dry mass (Md) into a test vessel or bottle (6.2.2). Record the exact weight of the sample.
Add 90 ml ± 5 ml of demineralised water (6.1.1). Start mixing using an appropriate stirring device (6.2.4). Maintain the temperature at 20 °C ± 5 °C during the whole test. NOTE 1 Some materials may form gas when in contact with water in acidic conditions. Therefore, it is highly recommended to allow possible gas exit by making a small hole in to the lid of the vessel or bottle. Test portion and water are stirred for 15 min ± 5 min and the pH of the slurry is measured and recorded before the acid addition. If pH < 2 already, this sample cannot be characterised with this test. After 15 min ± 5 min of stirring hydrochloric acid (6.1.2) is added based on the carbonate rating (8.2.2) of the test sample (see Table 1). This is considered the starting point of the test (t = 0). Stir the slurry throughout the test.
SIST EN 15875:2012



EN 15875:2011 (E) 11 Table 1 — Addition of acid based on carbonate rating Line numberCarbonate rating expressed as CO3-C mass fraction % Volume c(HCl) = 0,1 mol/l (6.1.2) to be added in ml at t = 0 (VA, t=0) 1 0 - 0,3 0,5 2 0,3 - 0,6 1,5 3 0,6 - 0,9 2,5 4 0,9 - 1,2 3,5 5 1,2 - 1,8 5 6 1,8 - 2,4 7 7 2,4 - 3,6 10 8 3,6 - 4,8 14 9 4,8 - 6,0 18 10 > 6,0 20 Measure and record the pH of the slurry after 22 h ± 15 min. If the pH is above 2,5 add HCl (6.1.2) to adjust the pH between 2,0 and 2,5. It is strongly recommended to adjust the pH as close as possible to 2,0 to ensure being in the range of pH = 2,0 to 2,5 at t = 24 h. Record the exact volume added (VA, t=22h) and the pH after the acid addition. If the pH at t = 22 h before acid addition is below pH = 2,0, too much acid was added in the beginning of the test and the test shall be repeated adding a smaller volume of acid. For the repeated test use the acid addition at start (t = 0) in table 1 one line above the one used in the discarded test. EXAMPLE 1 In the test the added HCl was VA, t=0 = 1,5 ml which corresponds to line 2 in table 1. At t = 22 h the measured pH was pH < 2.0 and the test was discarded. A new test is started with acid addition one line above compared to the discarded one which is line 1. Therefore the added HCl is VA, t=0 = 0,5 ml.
If VA, t=22h exceeds 50 % of total volume of acid (VA, t=0 + VA, t=22h), terminate the test at t = 22 h and start again as follows: Based on the total volume of acid added, choose a new volume for acid addition at t = 0 from table 1 so that VA, t=0 in the new test corresponds to the highest volume in the table that does not exceed the total volume of acid used in the discarded test (this is usually the volume of HCl addition one or two lines below in Table 1 of the discarded test). EXAMPLE 2 VA, t=0 = 1,5 ml is used corresponding to line 2 in Table 1. 3 ml of acid is needed at t = 22 h to reach pH 2,0.
VA, t=0 + VA, t=22h = 4,5 ml and the addition at t = 22 h is 66, 7% of the total addition. Therefore the test is terminated at
t = 22 h. Based on total consumption of 4,5 ml acid addition for the next test is VA, t=0 = 3,5 ml corresponding to line 4 in Table 1. If the volume of acid added at t = 22 h (VA, t=22h) does not exceed 50 % of total volume of acid, proceed further in testing as instructed in the next paragraph.
After 24 h ± 15 min, terminate the test and add demineralised water to the bottle to bring volume to approximately 125 ml. Measure and record the pH, making sure it is in the required range between pH = 2,0 and pH = 2,5. If the pH is outside the required pH range repeat the test applying a reduced (if pH < 2,0) or increased volume of acid (if pH > 2,5). If neither a smaller nor a bigger volume of initial acid addition from Table 1 leads to completion of the test due to problems described in examples above it is allowed to use an initial volume of acid deviating from Table 1. This deviation should be documented in the test report together with information of the acid volumes used in the preceding trials. EXAMPLE 3 VA, t=0 = 10 ml is used corresponding to line 7 in Table 1. At t = 22 h pH is adjusted to 2,0. Still, pH of the slurry is above 2,5 at t = 24 h. In the next trial VA, t=0 = 14 ml is used corresponding to line 8 in table 1 leading to pH of the slurry being below 2,0 at t = 22 h. For the following trial e.g. VA, t=0 = 12 ml may be tried. SIST EN 15875:2012



EN 15875:2011 (E) 12 NOTE 2 Materials usually contain other neutralizing compounds than calcium carbonate, which may react slower than calcium carbonate and thus leads to underestimation of NP. (See Annex B). Titrate the slurry to a pH of 8,3 using a sodium hydroxide solution (6.1.3). Record the exact volume of NaOH consumed in titration. NOTE 3 The end point of the back-titration is 8,3, being the usual endpoint for acidity titrations, corresponding to the stoichiometric equivalence point for carbonate/bicarbonate in natural waters in which carbonic acid is the most dominant weak acid. NOTE 4 An example of a data sheet for the recording of test results is given in Annex A, Table A.1. 8.2.4 Calculation Calculate the NP of the sample expressed as H+ content in mol/kg and as carbonate equivalents (CaCO3) in kg/t as follows: a) expressed as H+ content in mol/kg (Equation (5)) dBA(NaOH)(NaOH)(HCl)(HCl)NPMVcVc×−×= (5) where c(HCl)
is the con
...

SLOVENSKI STANDARD
oSIST prEN 15875:2009
01-januar-2009
[Not translated]
Characterization of waste - Static test for determination of acid potential of sulfidic waste
Charakterisierung von Abfällen - Statische Prüfung zur Bestimmung des
Säurebildungspotenzials von sulfidhaltigen Abfällen
Caractérisation des déchets - Essai statique pour la détermination du potentiel de
génération d'acide et du potentiel de neutralisation des déchets sulfurés
Ta slovenski standard je istoveten z: prEN 15875
ICS:
13.030.10 Trdni odpadki Solid wastes
oSIST prEN 15875:2009 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 15875:2009

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oSIST prEN 15875:2009
EUROPEAN STANDARD
DRAFT
prEN 15875
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2008
ICS 13.030.10

English Version
Characterization of waste - Static test for determination of acid
potential of sulfidic waste
Caractérisation des déchets - Essai statique pour la Charakterisierung von Abfällen - Statische Prüfung zur
détermination du potentiel de génération d'acide et du Bestimmung des Säurebildungspotenzials von
potentiel de neutralisation des déchets sulfurés sulfidhaltigen Abfällen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 292.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the
same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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 supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15875:2008: E
worldwide for CEN national Members.

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oSIST prEN 15875:2009
prEN 15875:2008 (E)
Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Symbols and abbreviations .5
5 Principle.6
6 Reagents and laboratory devices .6
6.1 Reagents.6
6.2 Laboratory devices.6
7 Sampling and sample preparation.7
7.1 Laboratory sample.7
7.2 Test sample .7
7.3 Determination of dry residue of the sample .7
7.4 Test portion for the determination of neutralisation potential (NP) .7
8 Test procedures.8
8.1 Part A: Determination of acid potential (AP).8
8.1.1 General.8
8.1.2 Total sulfur content .8
8.1.3 Disulfide (pyrite) content .8
8.1.4 Calculation.8
8.2 Part B: Determination of Neutralisation Potential (NP) .9
8.2.1 General.9
8.2.2 Carbonate rating (CR) .9
8.2.3 Neutralisation potential (NP) .9
8.2.4 Calculation.11
9 Calculation of Neutralisation Potential Ratio and Net Neutralisation Potential.11
10 Test report .12
Annex A (informative) Example of a data sheet .13
Annex B (informative) Operation and uses of the test: influence of parameters .14
B.1 Sulfur Determination .14
B.2 Particle size .14
B.3 Mineralogy.14
B.3.1 Sulfur minerals.14
B.3.2 Sources of acidity.17
Annex C (informative) Speciation of sulphur compounds.18
Annex D (informative) Explanation of formulas used.19
Acid Potential (AP).19
Carbonate rating (CR).20
Bibliography .21
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Foreword
This document (prEN 15875:2008) has been prepared by Technical Committee CEN/TC 292
“Characterization of waste”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
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1 Scope
This European standard specifies methods to determine the potential of sulfide bearing materials for the
formation of acidic drainage. Specified are methods for determining both the acid potential (AP) and the
neutralisation potential (NP) of the material. From these results the net neutralisation potential (NNP) and the
neutralisation potential ratio (NPR) are calculated.
This European standard is applicable to all sulfide bearing wastes from the extractive industries excluding
wastes which will have pH < 2 in the initial step of the procedure described in 8.2.3.
2 Normative references
The following referenced documents are indispensable for the application 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.
EN 13137 Characterization of waste – Determination of total organic carbon (TOC) in waste, sludges and
sediment
EN 14346 Characterization of waste – Calculation of dry matter by determination of dry residue or water
content
EN 14582 Characterization of waste – Determination of halogen and sulfur content; oxygen combustion in
closed systems and determination methods Method A: bomb combustion
EN 14899 Characterization of waste –- Sampling of liquid and granular waste materials including paste-like
materials and sludges- Part 1: A framework for sampling plan preparation
EN 15002 Characterization of waste - Preparation of test portions from the laboratory sample
ISO 351 Solid mineral fuels - Determination of total sulphur - High temperature combustion method
ISO 3310-1 Test sieves -- Technical requirements and testing -- Part 1: Test sieves of metal wire cloth
ISO 15178 Soil quality -- Determination of total sulfur by dry combustion
ISO 10694 Soil quality -- Determination of organic and total carbon after dry combustion (elementary analysis)
ISO 16720 Soil quality -- Pretreatment of samples by freeze-drying for subsequent analysis
3 Terms and definitions
3.1
laboratory sample
sample sent to or received by the laboratory
3.2
test sample
sample, prepared from the laboratory sample, from which test portions are removed for testing or analysis
3.3
test portion
quantity of material of proper size, for measurement of the concentration or other properties of interest, taken
from the test sample
NOTE The test portion may be taken from the laboratory sample directly if no preparation of sample is required (e. g.
samples of proper homogeneity, size and fineness).
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3.4
suspension
mixture of leachant and test portion
3.5
Acid potential (AP)
The maximum potential acid generation from a sample assuming that all sulfur occurs as pyrite and that
acidity will result from its complete oxidation
3.6
Neutralisation potential (NP)
The capacity of a sample to neutralise the generated acidity
3.7
Carbonate rating (CR)
Carbonate content of the sample used to specify the volume(s) of acid be added during the procedure (8.2.3)
3.8
Net neutralisation potential (NNP)
Difference of acid potential and neutralization potential
NNP = NP - AP
3.9
Neutralisation potential ratio (NPR)
Ratio of neutralization potential and acid potential
NPR = NP / AP
4 Symbols and abbreviations
AP acid potential
NP neutralisation potential
CR carbonate rating
M dry mass of the test portion
d
M un-dried mass of the test portion
w
o
m mass after drying at 105 C
d
m mass before drying (check later use of this)
w
M molecular weight of Sulfur
s
NNP net neutralisation potential
NPR neutralisation potential ratio
t=0 time at the start of the test
t=2h time at two hours from the start of the test
V volume of acid or base added
A/B
V volume of acid added at t=0
A, t=0
V volume of acid added at t=2h
A, t=2h
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V volume of acid added at t=22h
A, t=22h
w dry residue of the sample
dr
5 Principle
This test method consists of four parts:
a) Determination of total sulfur by bomb (EN 14582) or high temperature combustion (ISO 351 or ISO
15178) and calculation of acid potential (AP). Instead of total sulfur, sulfides may be determined using
techniques described in the informative Annex C.
b) Determination of carbonate content by dry combustion (ISO 10694 or EN 13137, part A) to give the
carbonate rating (CR).
c) Determination of the neutralisation potential (NP) by hydrochloric acid addition to reach pH=2 to pH=2,5
and back titration with sodium hydroxide to reach pH=8,3 after reaction time of 24 hours.
d) Calculations of the net neutralisation potential (NNP) and the neutralisation potential ratio (NPR) based
on AP and NP.
+
AP and NP are expressed as H content in mol/kg. The conversion factor is given for expression as carbonate
equivalents (CaCO3) in kg/t.
6 Reagents and laboratory devices
6.1 Reagents
6.1.1 Distilled or demineralised water
6.1.2 Hydrochloric acid (analysis grade), 1 mol/l
6.1.3.Sodium hydroxide (analysis grade), 0,1 mol/l
6.2 Laboratory devices
6.2.1 Analytical balance (accurate to 0,05 g)
6.2.2 Bottles or vessels (250 ml) made of inert material such as glass or high density polyethylene (HDPE) or
polypropylene (PP) and supplied with a lid of inert material (e.g. PTFE). Rinsing is compulsory.
6.2.3 Size reducing equipment, e.g. a jaw crusher, rotary swing mill, ball mill or similar device.
6.2.4 Stirring device or magnetic stirring device with magnetic bar coated with PTFE. The parts in contact with
the suspension shall be made of materials not affecting the outcome of the test like glass, PTFE.
6.2.5 pH meter with a measurement accuracy of at least ± 0,05 pH units.
6.2.6 Sample dividers (e.g. rotary splitter or riffle divider) or coning and quartering.
6.2.7 Sieves, conforming to the requirements of ISO 3310-1, with openings of 0,125 mm.
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7 Sampling and sample preparation
7.1 Laboratory sample
Perform sampling in accordance with EN 14899 in order to obtain a representative laboratory sample.
The laboratory sample shall have a mass of at least 1 kg (dry mass).
Note The mass of the laboratory sample is dependent on its maximum particle size and homogeneity. Further
information on sample masses can be obtained from EN 15002.
7.2 Test sample
Crush the laboratory sample to < 2 mm following the procedures given in EN 15002. Take a subsample from
the crushed material by e.g. using a suitable divider (6.2.7). The subsample of approximately 100 g is then
milled to a particle size of 95 % less than 0,125 mm.
Moist material that is not possible to sieve is dried prior to sieving and/or crushing. The drying temperature
°
shall not exceed 40 C in order to avoid unwanted reactions. Alternatively, freeze drying according to ISO
16720 can be used.
The crushed material can change upon storage due to ageing of fresh surfaces. It is therefore recommended
to test the material as soon as possible after crushing. If short term storage is needed, crushed material
should be stored cold and dark. For long term storage material should be dried (at temperatures not
exceeding 40°C) prior to storage to prevent acid generating reactions to take place.
7.3 Determination of dry residue of the sample
The whole test sample, complying with the size criteria in 7.2 shall not be further dried. The dry residue (w )
dr
of the test sample shall be determined on a separate test portion according to EN 14346.
° °
The dry residue of the sample shall be determined at 105 C ± 5 C according to EN 14346. The dry residue
expressed as mass fraction in percent is calculated as follows:
m
d
w = 100× (1)
dr
m
w
where
w is the dry residue of the sample expressed as mass fraction in percent;
dr
m is the mass after drying expressed in grams (g);
d
m is the mass of the sample after sample pretreatment as described in 7.2 and before drying expressed
w
in grams (g).
7.4 Test portion for the determination of neutralisation potential (NP)
Prepare a test portion by the use of a suitable divider (6.2.7) in accordance with EN 15002.
Calculate the mass of the test portion M in grams to be used for the test in accordance with equation 2:
w
M
d
(2)
M = ×100
w
w
dr
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where
M is the dry mass of the test portion expressed in grams (g);
d
M is the total mass of the test portion expressed in grams (g).
w
8 Test procedures
8.1 Part A: Determination of acid potential (AP)
8.1.1 General
The acid potential (AP) can be either based on the determination of total sulfur or on a species analysis where
sulfide sulfur is determined.
Analysis of total sulfur is a well established method with a high potential of automatisation resulting in short
analysis times. Total sulfur determination can therefore be regarded as a default method which is described in
8.1.2.
If either through mineralogical or chemical analysis it is shown that substantial parts of total sulfur is sulfate,
then a more appropriate (realistic) AP is obtained by analyzing sulfide sulfur directly or by subtraction of
sulfate sulfur from total sulfur. There are no CEN or ISO standards for this species analysis (see 8.1.3),
methods that are applicable are shown in the (informative) annex C.
Note The main source for acidity is the oxidation of sulfides. Total sulfur is used as a conservative approximation of
sulfide content. If a significant part of total sulfur is sulfate this will lead to a significant overestimation of AP, in which case
a more realistic assessment will be achieved if the AP determination is based on sulfide content.
8.1.2 Total sulfur content
Total sulfur content is determined either by bomb combustion according EN 14582 or by high temperature
combustion according ISO 351 or ISO 15178.
The bomb combustion method described in EN 14582 usually gives high recoveries when inorganic salts are
analysed. However, depending on the material to be analysed, suitable pure inorganic compounds with a
similar sulfur binding shall be used to test recovery rates.
When using high temperature combustion techniques operating conditions of the analysis have to be chosen
that all sulfur components including temperature stable inorganic sulfates (e.g. calcium sulfate) are detected.
This can be achieved by increasing the temperature (e.g. up to 1500 °C) or the use of tin capsules (which
burn in an exothermic reaction resulting in high temperatures). Also measuring time may be increased as
these stable compounds are reacting slower. Calibration has to be made with calibrants having the same
range of sulfur concentration as the material to be analysed.
8.1.3 Disulfide (pyrite) content
Methods for the determination of sulfur species (sulfate-, sulfide-, disulfide- sulfur) are not established for the
material described in this standard. Guidance is given in the informative Annex C.
NOTE Some sulfides do not contribute to AP, this can only be assessed through more detailed characterisation, such
as mineralogy.
8.1.4 Calculation
The acid potential (AP) is calculated based on the sulfur content (either total or sulfide sulfur) as follows:
NOTE Calculation of acid potential assumes all sulfur to appear as pyrite
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+
a) expressed as H content in mol/kg as follows:
AP = 0,625× w()S (3)
where
0,625 is the conversion factor (taking into account the conversion of units and that 1 mol of Sulfur in pyrite
+
creates 2 moles of H ) (for further explanation see Annex D)
w(S) is the sulfur (either total or sulfide sulfur) content as mass fraction in percent

b) expressed as carbonate equivalents (CaCO3) in kg/t
()
AP = 31,25× w S (4)
where
31,25 is the conversion factor (ratio of molecular masses of calcium carbonate (100 g/mol) and Sulfur (32
g/mol)) (for further explanation see Annex D)
w(S) is the sulfur (either total or sulfide sulfur) content as mass fraction in percent

+
Note AP and NP values expressed as H content in mol/kg can be converted to carbonate equivalents (CaCO3) in
kg/t by multiplying with 50. Likewise a AP or NP expressed in carbonate equivalents (CaCO3) in kg/t can be converted to
+
H content in mol/kg by multiplying with 0.02.
8.2 Part B: Determination of Neutralisation Potential (NP)
8.2.1 General
The amount of acid added for the test is crucial for the results obtained. Therefore the carbonate content is
determined first to give the carbonate rating. From this the required hydrochloric acid addition is taken from
table 1.
8.2.2 Carbonate rating (CR)
Determine the carbonate content following the procedure in EN 13137 part A (clause 10.3.3. of this standard)
or ISO 10694.
The carbonate carbon content obtained from EN 13137 (there named “inorganic carbon”) or ISO 10694 is
expressed as mass fraction in percent, it is used as Carbonate Rating in 8.2.3 (for further explanation see
Annex D).
NOTE Calculation of CO -NP assumes all carbonates to be neutralising. However, in reality some carbonates like
3
siderite or manganese carbonate do not contribute.
8.2.3 Neutralisation potential (NP)
Weigh test portion M corresponding to 2,00 g + 0,10 g of dry mass (M ) into a test vessel or bottle (6.2.2).
w d
Record the exact weight of the sample.
Add 90 ml + 5 ml of demineralised water (6.1.1). Start mixing using an appropriate stirring device (6.2.4).
Maintain the temperature at 20 °C ± 5 °C during the whole test.
The suspension is stirred for 15 ± 5 minutes and the pH of the solution is measured and recorded before the
acid addition. If pH < 2 already, this sample cannot be characterised with this test.
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Hydrochloric acid (6.1.2) is added based on the carbonate rating (8.2.2) of the test sample (see table 1) at
start (t=0). Add more acid after 2 hours (t=2h) (see table 1). Stir the suspension between each acid addition.
Temporary note: reference to Fizz test data to be decided after ruggedness study
Table 1 — Addition of acid based on carbonate rating
temporary note: simplification of table to be discussed when results from the robustness study are available
Row number Carbonate Rating Volume of HCl (6.1.2) to be added (ml)
(CR) expressed as
at t = 0 (V ) at t = 2h (V )
A, t=0 A, t=2h
CO -C mass fraction
3
(%)
1 0-0,3 0,5 0
2 0,3-0,6 1 0,5
3 0,6-0,9 1,5 1
4 0,9-1,2 2 1,5
5 1,2-1,8 3 2
6 1,8-2,4 4 3
7 2,4-3,6 5 5
8 3,6-4,8 7 7
9 4,8-6 9 9
10 >6 10 10

Measure and record the pH of the solution after 22 hours. If it is above pH 2,5, add HCl (6.1.2) to have final
pH between pH 2,0 and pH 2,5. Record the exact volume added (V ).
A, t=22h
If the pH is below pH = 2,0, too much acid was added in the beginning of the test and the test shall be
repeated adding a smaller volume of acid. For the repeated test use the acid addition pair at start (t=0) and
after 2 hours (t=2h) in table 1 one row above the one used in the discarded test.
Example: In the test the added HCl was V = 1 ml and V =0,5 ml which corresponds to row 2 in table 1.
A, t=0 A, t=2h
At t=22h the measured pH was pH < 2.0-and the test was discarded. A new test is started with acid additions
one row above compared to the discarded one which is row 1. Therefore the added HCl is V = 0,5 ml and
A, t=0
V = 0 ml.
A, t=2h
If V exceeds 50 % of total volume of acid (V +V +V ), terminate the test at t=22h and start
A, t=22h A, t=0 A, t=2h A, t=22h
again as follows: Based on the total volume of acid added, choose a new pair for acid additions at t=0h and
t=2h from table 1 so that VA, t=0+VA, t=2h in the new test corresponds to the highest volume in the table that does
not exceed the total volume of acid used in the discarded test (this is usually the pair of HCl addition one or
two rows below in table 1 of the discarded test).
Example: V = 1 ml and V =0,5 ml were used corresponding to row 2 in table 1. 3 ml of acid is needed
A, t=0 A, t=2h
at t=22h to reach pH-range of 2,0-2,5. V +V +V = 4,5 ml and the addition at t=22h is 66,7% of the
A, t=0 A, t=2h A, t=22h
total addition. Therefore the test is terminated at t=22h. Based on total consumption of 4,5 ml acid additions
for the next test are V = 2 ml and V =1,5 ml corresponding to row 4 in table 1.
A, t=0 A, t=2h
If the volume of acid added at t=22h (V ) does not exceed 50 % of total volume of acid, proceed further in
A, t=22h
testing as instructed in the next paragraph.
After 24 hours, terminate the test and add demineralised water to the bottle to bring volume to approximately
125 ml. Measure and record the pH, making sure it is in the required range between pH = 2,0 and pH = 2,5. If
the pH is outside the required pH range repeat the test applying a reduced (if pH < 2,0) or increased volume
of acid (if pH > 2,5).
Note Materials usually contain other neutralizing compounds than calcium carbonate, which may react slower than
calcium carbonate and thus leads to underestimation of NP. (See Annex B)
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Titrate the solution to a pH of 8,3 using a sodium hydroxide solution (6.1.3). Record the exact volume of
NaOH consumed in titration.
Note The end point of the back-titration is 8,3, being the usual endpoint for acidity titrations, corresponding to the
stoichiometric equivalence point for carbonate/bicarbonate in natural waters in which carbonic acid is the most dominant
weak acid.
8.2.4 Calculation
+ +
Calculate the NP of the sample expressed as H content in mol H /kg and as carbonate equivalents (CaCO3)
in kg/t as follows:
+
a) expressed as H content in mol/kg
c(HCl)×V (HCl)−c(NaOH)×V (NaOH)
(5)
NP=
Md
where
C(HCl) is the concentration of HCl in mol/l
V(HCl) is the volume of HCl added (V +V +V ) in ml
A, t=0 A, t=2h A, t=22h
C(NaOH) is the concentration of NaOH in mol/l
V(NaOH) is the volume of NaOH used in back titration in ml
M is the dry mass of the test portion expressed in grams (g)
d
b) expressed as carbonate equivalents (CaCO3) in kg/t
c(HCl )×V (HCl )−c(NaOH )×V (NaOH )
(6)
NP = 50× ( )
Md
9 Calculation of Neutralisation Potential Ratio and Net Neutralisation Potential
+
The acid potential (AP) and neutralisation potential (NP) are to be calculated in H content in mol/kg. The
resulting Neutralisation Potential Ratio - NPR ( potential for neutralisation of acidic drainages ) is assessed
using the formula:
NP
NPR= (7)
AP
Note A NPR <1 means that there is not enough neutralisation capacity to neutralise all potentially released acidity.
A significant excess of NP means that there is enough neutralisation capacity to neutralise all potentially released acidity.
In theory, a NPR >1 should be enough to avoid acidic drainage. However, the reaction rates may differ between AP
minerals and NP minerals. Different mineralogy and crystalline structure may also lead to different availability. Thus, there
is a range of NPR-values which will be interpreted as uncertain. (see Annex B)
The Net Neutralisation Potential (NNP) is calculated from AP and NP using the formula:
NNP= NP− AP (8)
Note: A negative NNP corresponds to a NPR <1 and means that the waste is potentially acid generating.
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Note While NPR is the preferred value in the screening and classification of mineral wastes, the NNP can be used
in the interpretation of test results. E.g. it gives an indication of how sensitive the result is to variations in NP and AP
+
A NNP expressed as H content in mol/kg can be converted to carbonate equivalents (CaCO3) in kg/t by
multiplying with 50. Like wise a NP expressed as carbonate equivalents (CaCO3) in kg/t t can be converted to
+
H content in mol/kg by multiplying with 0.02.
10 Test report
The following information shall be documented in such way that they are immediately available on request. In
the following list, at least, the items marked with an asterisk (*) shall be included in the test repor
...

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