1、Designation: D8187 18Standard Guide forInterpretation of Standard Humidity Cell Test Results1This standard is issued under the fixed designation D8187; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This kinetic test guide covers interpretation and coop-erative management of a standard laboratory weatheringprocedure, Test Method D5744
3、. The guide suggests strategiesfor analysis and interpretation of data produced by Test MethodD5744 on mining waste rock, metallurgical processing wastes,and ores.1.1.1 Cooperative management of the testing involvesagreement of stakeholders in defining the objectives of thetesting, analytical requir
4、ements, planning the initial estimate ofduration of the testing, and discussion of the results at decisionpoints to determine if the testing period needs to be extendedand the disposition of the residues.1.2 The humidity cell test (HCT) enhances reaction producttransport in the aqueous leach of a so
5、lid material sample ofspecified mass. Standard conditions allow comparison of therelative reactivity of materials during interpretation of results.1.3 The HCT measures rates of weathering product massrelease. Soluble weathering products are mobilized by afixed-volume aqueous leach that is performed
6、and collectedweekly. Leachate samples are analyzed for pH, alkalinity/acidity, specific conductance, sulfates, and other selectedanalytes which may be regulated in the environmental drainageat a particular mining or metallurgical processing site.1.4 This guide covers the interpretation of standard h
7、umid-ity cell tests conducted to obtain results for the followingobjectives:Guide and Objective SectionsA Confirmation of Static Testing Results 5 6B Evaluation of Reactivity and Leachate Qualityfor Segregating Mine, Processing Waste, orOre7 8C Evaluation of Quality of NeutralizationPotential Availa
8、ble to React with ProducedAcid9 101.5 This guide is intended to facilitate use of Test MethodD5744 to meet kinetic testing regulatory requirements formetallurgical processing products, mining waste rock, and oressized to pass a 6.3-mm (0.25-in.) Tyler screen.1.5.1 Interpretation of standard humidity
9、 cell test results hasbeen found to be useful for segregation of ore and waste anddesign of proper stockpiling and disposal facilities.1.6 Interlaboratory testing of the standard D5744 humiditycell has been confined to mine waste rock. Application of thisguide to metallurgical processing waste (for
10、example, millprocess tailings) is not supported by interlaboratory test data.Method B of Test Method D5744, however, has been founduseful for testing of metallurgical products, and this guide isalso useful for interpretation of those results (1).21.7 This guide is intended to describe various proced
11、ures forinterpreting the results from standard laboratory weathering ofsolid materials in accordance with Test Method D5744. It doesnot describe all types of sampling and analytical requirementsthat may be associated with its application, nor all proceduresfor interpretation of results.1.8 The value
12、s stated in SI units are to be regarded asstandard. No other units of measurement are included in thisguide.1.8.1 ExceptionThe values given in parentheses are forinformation only.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespon
13、sibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-iza
14、tion established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.1This guide is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct
15、 responsibility of Subcommittee D34.01.04 on WasteLeaching Techniques.Current edition approved April 1, 2018. Published May 2018. Originallyapproved in 2018. DOI: 10.1520/D8187-18.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM Internation
16、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides
17、 and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12. Referenced Documents2.1 ASTM Standards:3D5681 Terminology for Waste and Waste ManagementD5744 Test Method for Laboratory Weathering of SolidMaterials Using a Humidity CellD6234 Test Method for
18、 Shake Extraction of Mining Wasteby the Synthetic Precipitation Leaching ProcedureE1915 Test Methods for Analysis of Metal Bearing Ores andRelated Materials for Carbon, Sulfur, and Acid-BaseCharacteristicsE2242 Test Method for Column Percolation Extraction ofMine Rock by the Meteoric Water Mobility
19、Procedure3. Terminology3.1 DefinitionsFor definitions of terms used in this guide,see Terminology D5681.3.2 Definitions of Terms Specific to This Standard:3.2.1 acid concentration present (ACP), nin static acid-base classification, an estimate of mineral acidity determinedby titration of a sample sl
20、urry with water.3.2.2 acid generation potential (AGP), nin static acid-base classification, an estimate of sulfidic mineral contentdetermined from mineralogy or the sulfide sulfur content.3.2.3 acid neutralization potential (ANP), nin acid-baseclassification, an estimate of basic mineral content det
21、erminedfrom mineralogy, the carbonate carbon content, or acid neu-tralization potential acidity titration result. The preferred esti-mate for use is based on the capacity of the mineral to maintaincircumneutral pH as it dissolves.3.2.4 adaptive management plan (AMP), nin environmen-tal kinetic testi
22、ng, a structured, iterative process of robustdecision making in the face of uncertainty, with an aim toreduce uncertainty over time via system monitoring.3.2.5 decision point, nin management of a humidity celltest operation, a point in time during the operation of ahumidity cell that is selected, du
23、ring the planning stage, for thestakeholders to meet and make decisions on whether tocontinue or modify the operation of the test.3.2.6 humidity cell performance database, na compilationof: (1) tested rock sample, mining waste, ore, or metallurgicaltailings characterization; (2) completed sample col
24、lection rep-resenting the geological classifications and acid-base charac-teristics; and (3) humidity cell field weathering test reports, foruse in planning and interpretation of HCTs.3.2.7 mining waste, noverburden or waste rock excavatedand disposed of during mining operations.3.3 SymbolsVariables
25、 listed in this guide are defined in theindividual sections in which they are discussed.4. Significance and Use4.1 Use of HCT Data and Testing ObjectivesThe labora-tory weathering test method (D5744) generates data that can beused to:4.1.1 Determine whether a solid material will produce anacidic, al
26、kaline, or neutral effluent;4.1.2 Identify solutes in the effluent that represent dissolvedweathering products formed during a specified period of time,and inform the user of their potential to produce environmentalimpacts at a mining or metallurgical processing site underproposed operating conditio
27、ns;4.1.3 Determine the mass of solute release; and4.1.4 Determine the rate at which solutes are released (fromthe solids into the effluent) under the closely controlledconditions of the test for comparison to other materials.4.1.5 These approaches are based on the existence ofdetailed mineralogical
28、work and static tests that provide a basisfor interpreting HCT results.4.1.6 Detailed mineralogical work might lead a reviewer tosuspect either acid neutralization potential (ANP) or acidgeneration potential (AGP) minerals have questionableavailability, which would be a significant factor in interpr
29、etingHCT results and decisions concerning test duration.4.2 Interpretation of data generated by the laboratory weath-ering procedure can be used to address the following objec-tives:4.2.1 Determine the variation of drainage quality as afunction of compositional variations (for example, iron sulfidea
30、nd calcium plus magnesium carbonate contents) within indi-vidual mine rock lithologies;4.2.2 Determine the amount of acid that can be neutralizedby the sample while maintaining a drainage pH of 6.0 underthe conditions of the test;4.2.3 Estimate mine rock weathering rates to aid in predict-ing the en
31、vironmental behavior of mine rock; and4.2.4 Determine mine rock weathering rates to aid inexperimental design of site-specific kinetic tests.4.3 Interpretation ApproachesGuides A, B, and C areintended as examples of what to consider in developing anapproach for determining how reasonable objectives
32、for hu-midity cells might be structured, and some possible criteria forcooperative management of HCTs involving stakeholders.4.3.1 It is also possible to use an approach to establish adecision point, rather than an end point, to the humidity celltest during the planning stage. Guides A, B, and C are
33、examples of techniques and associated criteria comprisingsome approaches to help interpret data generated by humiditycell tests. Decision points can be established during theplanning stage to allow stakeholders an opportunity to reviewthe results and decide if additional weathering cycles areneeded
34、to meet the objectives of the testing.4.3.2 Continuation of the HCT beyond the decision pointmay or may not provide important information regarding theacceleration or deceleration of oxidation and metal leaching inthe material being tested.4.3.3 More detailed leachate information from a longerHCT ma
35、y be critical information for designing waste manage-ment or water treatment facilities as accounted for in an AMP,3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to t
36、he standards Document Summary page onthe ASTM website.D8187 182but an agreed-upon endpoint of test objectives would allow fora decision that advances mine planning and permitting.4.3.4 The laboratory weathering procedure provides condi-tions conducive to oxidation of solid material constituents ande
37、nhances the transport of weathering reaction products con-tained in the resulting weekly effluent. This is accomplished bycontrolling the exposure of the solid material sample to suchenvironmental parameters as reaction environment temperatureand application rate of water and oxygen.4.3.5 Because ef
38、ficient removal of reaction products is vitalto track mineral dissolution rates during the procedure, labo-ratory leach volumes are large per unit mass of rock to promotethe rinsing of weathering reaction products from the mine rocksample. Interpretation of laboratory kinetic tests by comparisonwith
39、 field tests has shown that more reaction products frommineral dissolution are consistently released per unit weightand unit time in laboratory weathering tests (2). For example,sulfate release rates observed in laboratory tests of metal minerock have been reported to be three to eight times those f
40、orsmall-scale field test piles of Duluth complex rock (3), andfrom two to 20 times those for small-scale field test piles ofArchean greenstone rock (4). A greater increase is anticipatedwhen laboratory rates are compared with field rates measuredfrom operational waste rock piles.4.4 In some cases, i
41、t may be useful to establish criteria fora decision to end the weathering cycles for a particular cellbased on HCT results but still continue to maintain the HCTtest weathering cycles for a longer duration.4.4.1 In other cases, it might be useful to have duplicateHCTs and use one as a basis for a de
42、cision point andsubsequent destructive evaluation of reaction products.4.4.1.1 The duplicate cell could be maintained to confirmthe basis for the decision and be used to update the AMP andfinancial guarantee, if necessary.4.4.2 This approach supports a decision concerning minewaste management and pl
43、anning, including an AMP.4.4.3 This approach does not necessarily resolve the needfor accurate prediction of long-term metal leaching and drain-age quality, but is recommended as a tool for making decisionson how to conduct testing with the objective of determininghow ore and waste will be handled a
44、nd monitored, and thepotential level of risk involved in related decisions for specificsites and materials.4.5 Continuing HCT weathering cycles for an extendedperiod of time may also provide a higher level of certainty.4.6 Depending on the site-specific resources at risk andbehavior of waste materia
45、ls, an extended HCT weatheringcycle duration may be an important consideration for stake-holder groups to use in evaluating HCTs.4.7 As a mine typically involves very large quantities ofwaste rock, which will be leached by at least some amount ofincident precipitation for extended times, ongoing mon
46、itoringof waste facility performance, including any produced effluentor leachate, is almost always required as a condition of permitapproval.4.8 Performance monitoring of permitted facilities can be acritical element in the development of a humidity cell perfor-mance database, as well as support for
47、 the evolving HCTweathering cycle duration criteria and approach proposed here.4.9 A humidity cell performance database could be devel-oped in a standard format to allow comparison of laboratoryweathering results with drainage from field waste facilityperformance, based on publicly available informa
48、tion.4.9.1 A model approach with possible objectives and crite-ria are presented below as examples to help interpret HCTresults.4.10 Variations in specific approach requirements and crite-ria (% sulfur, sulfide sulfur, carbonate, pH, sulfate release, etc.)will depend on the site-specific objectives,
49、 deposit mineralogy,and characterization, including various static test results andmanagement plans agreed upon by stakeholders.4.10.1 Regardless of the site-specific stakeholder objectives,instability in metal release rates should strongly suggestcontinuation of weathering cycle testing.4.10.2 Regardless of the decision process followed, theultimate responsibility for the permitting decision lies with thepermitting agency(s), and the ultimate environmental liabilityand operating responsibility lies with the mining company.4.11 These approaches are suggested a
