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1、a Date: 25 November 2008 Origin: European Latest date for receipt of comments: 28 February 2009 Project no.: 2008/02870 Responsible committee: B/508/3 Characterization of waste Interested committees: Title: Draft BS EN 15875 Characterization of waste - Static test for determination of acid potential
2、 of sulfidic waste Supersession information: If this document is published as a standard, the UK implementation of it will supersede NONE and partially supersede. NONE If you are aware of a current national standard which may be affected, please notify the secretary (contact details below). WARNING:
3、 THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND 28 February 2009. This draft is issued to allow comments from interested parties; all comments will be given consideration prior to publication. No acknowledgement will normally be sent. See ove
4、rleaf for information on commenting. No copying is allowed, in any form, without prior written permission from BSI except as permitted under the Copyright, Designs and Patent Act 1988 or for circulation within a nominating organization for briefing purposes. Electronic circulation is limited to diss
5、emination by e-mail within such an organization by committee members. Further copies of this draft may be purchased from BSI Customer Services, Tel: +44(0) 20 8996 9001 or email . British, International and foreign standards are also available from BSI Customer Services. Information on the co-operat
6、ing organizations represented on the committees referenced above may be obtained from the responsible committee secretary. Cross-references The British Standards which implement International or European publications referred to in this draft may be found via the British Standards Online Service on
7、the BSI web site http:/. Direct tel: 020 8996 7233 Responsible Committee Secretary: Mr W R Kerrigan (BSI) E-mail: Draft for Public Comment Head Office 389 Chiswick High Road London W4 4AL Telephone: +44(0)20 8996 9000 Fax: +44(0)20 8996 7001 Form 36 Version 8.0 DPC: 08/30189276 DC Licensed Copy: Lo
8、ndon South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI b Introduction This draft standard is based on European discussions in which the UK has taken an active part. Your comments on this draft are welcome and will assist in the preparation of the consequent B
9、ritish Standard. Comment is particularly welcome on national, legislative or similar deviations that may be necessary. Even if this draft standard is not approved by the UK, if it receives the necessary support in Europe, the UK will be obliged to publish the official English Language text unchanged
10、 as a British Standard and to withdraw any conflicting standard. UK Vote Please indicate whether you consider the UK should submit a negative (with reasons) or positive vote on this draft. Submission The guidance given below is intended to ensure that all comments receive efficient and appropriate a
11、ttention by the responsible BSI committee. Annotated drafts are not acceptable and will be rejected. All comments must be submitted, preferably electronically, to the Responsible Committee Secretary at the address given on the front cover. Comments should be compatible with Version 6.0 or Version 97
12、 of Microsoft Word for Windows, if possible; otherwise comments in ASCII text format are acceptable. Any comments not submitted electronically should still adhere to these format requirements. All comments submitted should be presented as given in the example below. Further information on submitting
13、 comments and how to obtain a blank electronic version of a comment form are available from the BSI web site at: http:/ Template for comments and secretariat observations Date: xx/xx/200x Document: ISO/DIS xxxxx 1 2 (3) 4 5 (6) (7) MB Clause No./ Subclause No./ Annex (e.g. 3.1) Paragraph/ Figure/Tab
14、le/ Note (e.g. Table 1) Type of com- ment Comment (justification for change) by the MB Proposed change by the MB Secretariat observations on each comment submitted 3.1 Definition 1 ed Definition is ambiguous and needs clarifying. Amend to read . so that the mains connector to which no connection . 6
15、.4 Paragraph 2 te The use of the UV photometer as an alternative cannot be supported as serious problems have been encountered in its use in the UK. Delete reference to UV photometer. Microsoft and MS-DOS are registered trademarks, and Windows is a trademark of Microsoft Corporation. Licensed Copy:
16、London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM DRAFT prEN 15875 November 2008 ICS 13.030.10 English Version Characterization of waste - Static test for determination of acid potential of sulfidic was
17、te Caractrisation des dchets - Essai statique pour la dtermination du potentiel de gnration dacide et du potentiel de neutralisation des dchets sulfurs Charakterisierung von Abfllen - Statische Prfung zur Bestimmung des Surebildungspotenzials von sulfidhaltigen Abfllen This draft European Standard i
18、s 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 na
19、tional 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 Cent
20、re 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, Polan
21、d, 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 E
22、uropean 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 COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050
23、Brussels 2008 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. prEN 15875:2008: E Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI prEN 15875:2008 (E) 2 Contents Page Forew
24、ord3 1 Scope 4 2 Normative references4 3 Terms and definitions .4 4 Symbols and abbreviations5 5 Principle6 6 Reagents and laboratory devices 6 6.1 Reagents.6 6.2 Laboratory devices6 7 Sampling and sample preparation.7 7.1 Laboratory sample.7 7.2 Test sample7 7.3 Determination of dry residue of the
25、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 General8 8.1.2 Total sulfur content .8 8.1.3 Disulfide (pyrite) content 8 8.1.4 Calculation8 8.2 Part B: Determination of Neutralisation Po
26、tential (NP) .9 8.2.1 General9 8.2.2 Carbonate rating (CR) .9 8.2.3 Neutralisation potential (NP) 9 8.2.4 Calculation11 9 Calculation of Neutralisation Potential Ratio and Net Neutralisation Potential11 10 Test report12 Annex A (informative) Example of a data sheet13 Annex B (informative) Operation
27、and uses of the test: influence of parameters14 B.1 Sulfur Determination .14 B.2 Particle size14 B.3 Mineralogy14 B.3.1 Sulfur minerals.14 B.3.2 Sources of acidity17 Annex C (informative) Speciation of sulphur compounds.18 Annex D (informative) Explanation of formulas used.19 Acid Potential (AP)19 C
28、arbonate rating (CR).20 Bibliography21 Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI prEN 15875:2008 (E) 3 Foreword This document (prEN 15875:2008) has been prepared by Technical Committee CEN/TC 292 “Characterization of waste”, the
29、secretariat of which is held by NEN. This document is currently submitted to the CEN Enquiry. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI prEN 15875:2008 (E) 4 1 Scope This European standard specifies methods to determine the poten
30、tial 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
31、 calculated. This European standard is applicable to all sulfide bearing wastes from the extractive industries excluding wastes which will have pH 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. Reco
32、rd the exact volume added (VA, 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 t
33、he one used in the discarded test. Example: In the test the added HCl was VA, t=0 = 1 ml and VA, t=2h =0,5 ml which corresponds to row 2 in table 1. At t=22h the measured pH was pH 2,5). Note Materials usually contain other neutralizing compounds than calcium carbonate, which may react slower than c
34、alcium carbonate and thus leads to underestimation of NP. (See Annex B) Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI prEN 15875:2008 (E) 11 Titrate the solution to a pH of 8,3 using a sodium hydroxide solution (6.1.3). Record the ex
35、act 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 C
36、alculation 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 dM NaOHVNaOHcHClVHClc NP )()()()( = (5) where C(HCl) is the concentration of HCl in mol/l V(HCl) is the volume of HCl added (VA
37、, t=0+VA, t=2h+VA, t=22h) in ml C(NaOH) is the concentration of NaOH in mol/l V(NaOH) is the volume of NaOH used in back titration in ml Md is the dry mass of the test portion expressed in grams (g) b) expressed as carbonate equivalents (CaCO3) in kg/t ) )()()()( (50 dM NaOHVNaOHcHClVHClc NP = (6) 9
38、 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
39、using the formula: AP NP NPR = (7) Note 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 wi
40、ll be interpreted as uncertain. (see Annex B) The Net Neutralisation Potential (NNP) is calculated from AP and NP using the formula: APNPNNP= (8) Note: A negative NNP corresponds to a NPR 22 B.3.2 Sources of acidity Two key sources contribute to acid generation from extractive wastes: primary source
41、s (sulfide oxidation) and secondary sources (sulfate dissolution). This CEN Standard assumes all acid is generated from primary sources, although the back-titration used to determine NP neutralises any acidity produced by the sample during the time of the test. B.3.2.1 Primary sources of acidity Pri
42、mary acid-generating minerals are sulfides of the type, MS2, the most common being Pyrite (FeS2). Oxidation of pyrite is often simplified by the following stoechiometric equations: 4 FeS2(s) + 15 O2(aq) + 14 H2O 4 Fe(OH)3(s) + 8 SO42-(aq) + 16 H+(aq) or 2 FeS2+7 O2(aq)+2H2O 2 FeSO4(aq)+2H2SO4 Howeve
43、r, a better representation is given in Figure 1. Oxygen path FeS2+7/2O2(aq)+H2OFe2+2SO42-+2H+ (1) Ferric ion path FeS2+14Fe3+8H2O15Fe2+2SO42-+16H+ (2) Oxidation of ferric ion 2Fe2+2H+0,5O2 2Fe3+ +H2O (3) Hydration of ferric ion Fe3+3H2OFe(OH)3+3H+(4) Figure 1 Iron redox cycling. Pyrite oxidation by
44、1) dissolved molecular oxygen and 2) aqueous ferric iron; 3) Oxidation of aqueous ferrous iron by oxygen. 4) Solubility equilibrium between aqueous solution and Fe(OH)3(s) (Salmon, 2003). Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:04, Uncontrolled Copy, (c) BSI
45、 prEN 15875:2008 (E) 18 Annex C (informative) Speciation of sulphur compounds Speciation of sulfur compounds is a difficult task and is depending on the material to be analysed. There are no CEN or ISO standards that can be directly used for this purpose. Some guidance is given in the following clau
46、ses. A speciation method for coal is ISO 157 Coal - Determination of forms of sulfur. Sulfides are leached with HCl and disulfide (pyrite) by HCl with Cr3+ added. Sulfates are determined by adding H2O2 to the latter mixture. Organic (or perhaps better: non-soluble) sulfur is determined by difference
47、 (subtracting sum of sulfur species from total sulfur). This method has been applied to tailing materials. A similar method is described by Sobek et.al. who use HNO3 instead of H2O2/HCl/Cr3+. A completely different approach is high temperature combustion at different temperatures with IR detection.
48、It could be shown on minerals and tailing samples that pyrite completely reacts to SO2 at temperatures of 810C. Total sulfur (mainly sulfates and pyrite) was measured at 1350C. A comparison of ISO 157 and IR-method on a tailings sample showed the results presented in table C.1: Table C.1 Comparison
49、of ISO 157 and IR-method on a tailings sample ISO 157 IR 810C/1350C Species Mass fraction (%) Mass fraction (%) Total S 16,4 17,0 Sulfide S 0,2 Pyrite S 13,4 14,7 Sulfate S 0,7 (2,3) “Non-soluble” S (2,1) Values in brackets are calculated as difference to total sulphur. The following method for species analysis is described in ASTM E-1915-7a: Sulfide by pyrolysis loss at 550C for one ho