1、Designation: D7572 11aStandard Guide forRecovery of Aqueous Cyanides by Extraction from MineRock and Soil After Remediation of Process Releases1This standard is issued under the fixed designation D7572; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide is applicable for the collection, extractionand preservation of extracts f
3、rom mine rock and soil samplesfor the analysis of cyanide in the extracts. Responsibilities offield sampling personnel and the laboratory are indicated.1.2 The sampling, preservation and extraction proceduresdescribed in this practice are recommended for the analysis oftotal cyanide, available cyani
4、de, weak acid dissociable cya-nide, and free cyanide by Test Methods D2036, D4282, D4374,D6888, D6994, D7237, and D7284. The information suppliedin this practice can also be applied to other analytical methodsfor cyanide, for example, US EPA Method 335.4.1.3 The values stated in SI units are to be r
5、egarded asstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to
6、use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD1293 Test Methods for pH of WaterD2036 Test Methods for Cyanides in WaterD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD3856 Guide
7、 for Good Laboratory Practices in Laborato-ries Engaged in Sampling and Analysis of WaterD4282 Test Method for Determination of Free Cyanide inWater and Wastewater by MicrodiffusionD4374 Test Methods for Cyanides in WaterAutomatedMethods for Total Cyanide, Weak Acid Dissociable Cya-nide, and Thiocya
8、nateD4840 Guide for Sample Chain-of-Custody ProceduresD4841 Practice for Estimation of Holding Time for WaterSamples Containing Organic and Inorganic ConstituentsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD6888 Test Method for Available Cyani
9、de with LigandDisplacement and Flow Injection Analysis (FIA) UtilizingGas Diffusion Separation and Amperometric DetectionD6994 Test Method for Determination of Metal CyanideComplexes in Wastewater, Surface Water, Groundwaterand Drinking Water Using Anion Exchange Chromatogra-phy with UV DetectionD66
10、96 Guide for Understanding Cyanide SpeciesD7237 Test Method for Free Cyanide with Flow InjectionAnalysis (FIA) Utilizing Gas Diffusion Separation andAmperometric DetectionD7284 Test Method for Total Cyanide in Water by MicroDistillation followed by Flow Injection Analysis with GasDiffusion Separatio
11、n and Amperometric DetectionD7365 Practice for Sampling, Preservation and MitigatingInterferences in Water Samples for Analysis of CyanideD7511 Test Method for Total Cyanide by Segmented FlowInjection Analysis, In-Line Ultraviolet Digestion and Am-perometric Detection2.2 U.S. EPA Methods:3EPA OIA-16
12、77 Available Cyanide in WaterEPA Method 335.2 Cyanide, Total (Titrimetric; Spectropho-tometric)EPA Method 335.4 Determination of Total Cyanide bySemi-Automated Colorimetry3. Terminology3.1 Definitions: For definitions of terms used in this prac-tice, refer to Terminology D1129 and Guide D6696.1This
13、practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.06 on Methods for Analysis forOrganic Substances in Water.Current edition approved June 15, 2011. Published July 2011. Last previousedition published 2009 as D757209. DOI: 10.1520/D7
14、572-11A.2For 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 the standards Document Summary page onthe ASTM website.3Available from United States Environmental Protectio
15、n Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of
16、 Terms Specific to This Standard:3.2.1 mine rock, nore, waste rock or overburden exca-vated in order to construct an ore-processing site, or recovermetals or minerals during mining operations; or coarse pro-cessed ore such as heap-leach spoils.3.2.2 nominal size, nnin sampling, for a screen of thest
17、andard series, the opening that would pass 95 % of arepresentative sample.3.2.3 refrigeration, nstoring the sample between its freez-ing point and 6C.4. Summary of Guide4.1 Samples are collected in appropriate containers at thesampling site, refrigerated and transported to the laboratorywhere they a
18、re weighed, sub-sampled, the moisture is deter-mined and cyanides are extracted prior to analysis. Results ofthe analysis of the extract are applied to the original solidsample to determine the apparent concentration of cyanidesdissolved in water present in the solids as the result of theprocess rel
19、ease.5. Significance and Use5.1 This practice is intended as a means for obtaining anextract from mine rock and soil samples to measure cyanideconcentrations. Cyanide is analyzed in mine rock and soilextracts for measurement of cyanide concentration; however,improper sample collection and extraction
20、 can result in signifi-cant positive or negative bias.5.2 This practice is designed to mobilize aqueous cyanidespresent in the solids, so that the resulting extract can be used toassess leachate that could potentially be produced from minerock or soil.5.3 This practice is not intended to simulate ac
21、tual siteleaching conditions.5.4 This practice produces extracts that are amenable to thedetermination of trace cyanides. When trace cyanides are beingdetermined, it is especially important that precautions be takenin sample preservation, storage and handling to avoid possiblecontamination of the ex
22、tracts.5.5 This practice uses a comparative test method and isintended for use as a routine method for monitoring mine rockand soils. It is assumed that all who use this practice will betrained analysts capable of performing it skillfully and safely.It is expected that work will be performed in a pr
23、operlyequipped laboratory applying appropriate quality control prac-tices such as those described in Guide D3856.5.6 This practice identifies proper methods for obtainingmine rock and soil samples for the specific purpose ofmeasuring cyanide concentrations.6. Interferences6.1 Many interferences are
24、known for the analysis ofcyanide and could effect the results of the analysis of extractsproduced using this practice. Refer to Practice D7365 forproper handling of the extracts during sampling, mitigation ofinterferences and preservation prior to cyanide analysis.6.2 Unless otherwise specified, sam
25、ples must be extractedas soon as possible after sampling and the extracts must beanalyzed within 14 days; however, it is recommended toestimate the actual holding time for each new sample matrix asdescribed in Practice D4841. Certain sample matrices mayrequire immediate analysis to avoid cyanide deg
26、radation due tointerferences. A holding time study is required if there isevidence that cyanide degradation occurs from interferenceswhich would cause the holding time to be less than specified inthis practice or Practice D7365. Potential interferences forcyanide analytical methods are shown in Tabl
27、e 1.7. Apparatus7.1 Agitation Equipment, of any type that rotates the extrac-tion vessel in an end-over-end fashion at a rate of 30 6 2 r/minsuch that the axis of rotation is horizontal and it passes throughthe center of the bottle (see Fig. 1).7.2 Drying Pans or Dishes, for moisture content determi
28、na-tions, 500 g to 8 kg capacity.7.3 Drying OvenAny thermostatically controlled dryingoven capable of maintaining a steady temperature of 62C ina range of 100 to 110C.7.4 Extraction Vessels, cylindrical, wide-mouth, of a com-position suitable to the nature of the mine rock or soil andcyanide analyse
29、s to be performed, constructed of materials thatwill not allow sorption of the constituents of interest, andsturdy enough to withstand the impact of the falling samplefragments. The size of the container should be selected so thatthe sample, plus extraction fluid occupy approximately5095 % of the co
30、ntainer in order to provide good mixingwithout overfilling. The containers must have water-tightclosures of sufficient diameter to fill with the samples.7.5 Filtration Device, pressure or vacuum of a compositionsuitable to the nature of the analyses to be performed andequipped with a pre-washed glas
31、s wool or equivalent filter. Anassembly for pre-filtration or a centrifuge may be required iffiltration is difficult. WarningAvoid passing excessiveamounts of air through the sample during filtration to preventliberation of toxic hydrogen cyanide or cyanogen chloride gas.7.6 Laboratory Balance, capa
32、ble of weighing to 1.0 g.7.7 pH Meter, with a readability of 0.01 units and anaccuracy of at least 60.1 units at 25C.7.8 Riffle Splitter, A stationary sampler comprising an evennumber of equally-sized, adjacent chutes discharging in oppo-site directions. For use with this practice, there must be ami
33、nimum of twelve contained chutes (not bars) with anopening width of at least 3 times the nominal size.NOTE 1For riffle splitting finer materials ( 12.5 mm) it isrecommended not to exceed 312 times nominal size as it is required thatthe full width of the riffle be used since the accuracy of the split
34、 increaseswith the number of chutes. For free-flowing materials, the 3 times top sizemay be reduced to 112 times provided it is ascertained that there is nochute plugging for a particular material7.9 Rotary Sample Divider, A rotating sampler fed from asingle point comprising equally-sized or adjusta
35、ble propor-tional collection pans. For use with this practice, there must bea minimum opening width of at least 3 times the nominal size.D7572 11a2TABLE 1 Examples of Potential Interferences if not Mitigated in Standard Cyanide MethodsMethod Description Measurement Interferences NumberTotalCyanideAu
36、tomatedUVColorimetric AldehydesColorFatty AcidsMercuryNitrateNitriteOxidantsSulfidesTurbiditySulfur CompoundsThiocyanateCFR Kelada-01D4374TotalCyanideManualDistillationMgCl2Amperometric AldehydesCarbonatesNitriteNitrateOxidantsSulfideSulfur CompoundsThiocyanateD7284D2036 Test Method ATotalCyanideMan
37、ualDistillationMgCl2Manual orAutomatedColorimetricAldehydesCarbonatesFatty AcidsNitrateNitriteOxidantsSugarsSulfideSulfur CompoundsThiocyanateColorTurbidityD2036 Test Method AStandard Methods 4500-CN C/E,EPA Method 335.2,EPA Method 335.4TotalCyanideManualDistillationMgCl2ISE AldehydesCarbonatesFatty
38、 AcidsNitrateNitriteOxidantsSulfideSulfur CompoundsThiocyanateColorTurbidityD2036 Test Method ATotalCyanideManualDistillationMgCl2Titrimetric AldehydesCarbonatesFatty AcidsNitrateNitriteOxidantsSugarsSulfideSulfur CompoundsThiocyanateTurbidityD2036 Test Method ATotalCyanideMicrodistillationAmperomet
39、ric CarbonatesOxidantsSulfideD7284TotalCyanideUV/FIA Amperometric CarbonatesOxidantsSulfideD7511AvailableCyanideFlow InjectionLigand ExchangeAmperometric CarbonatesOxidantsSulfideD6888, EPA OIA-1677D7572 11a3TABLE 1 ContinuedMethod Description Measurement Interferences NumberCyanideAmenable toChlori
40、nationAlkalineChlorination andManualDistillationsManualColorimetricAldehydesCarbonatesFatty AcidsNitrateNitriteOxidantsSulfideSulfur CompoundsThiocyanateColorTurbidityUnknowns that cause negative resultsD2036 Test Method BWeak AcidDissociableCyanideBufferedDistillationManualColorimetricAldehydesCarb
41、onatesFatty AcidsNitrateNitriteOxidantsSugarsSulfideSulfur CompoundsThiocyanateTurbidityD2036 Test Method CWeak AcidDissociableCyanideAutomatedMethodAutomatedColorimetricAldehydesColorFatty AcidsMercuryNitrateNitriteOxidantsSulfidesTurbidityD4374Weak AcidDissociableCyanideBufferedDistillationISE Ald
42、ehydesCarbonatesFatty AcidsNitrateNitriteOxidantsSugarsSulfideSulfur CompoundsThiocyanateTurbidityD2036 Test Method CWeak AcidDissociableCyanideBufferedDistillationTitrimetric AldehydesCarbonatesFatty AcidsNitrateNitriteOxidantsSugarsSulfideSulfur CompoundsThiocyanateTurbidityD2036 Test Method CWeak
43、 AcidDissociableCyanideManualColorimetricAldehydesCarbonatesFatty AcidsNitriteNitrateOxidantsSugarsSulfideSulfur CompoundsThiocyanateVolatile CompoundsD2036 Test Method BD7572 11a4TABLE 1 ContinuedMethod Description Measurement Interferences NumberMetalCyanideComplexesIonChromatographyUV CarbonateDi
44、ssolved SolidsMetal AnionsMetal CationsOxidantsPhotodecompositionD6994Free Cyanide Flow Injection Amperometric CarbonateOxidantsSulfideD7237Free Cyanide Microdiffusion Colorimetric AldehydesOxidantsSulfideSulfur CompoundsD4282FIG. 1 ExtractorsD7572 11a58. Reagents8.1 Purity of ReagentsReagent grade
45、chemicals shall beused in this practice. Unless otherwise indicated, it is intendedthat all reagents shall conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety, where such specifications are available.4Other gradesmay be used, provided it is first asce
46、rtained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water that meetsthe purity specifications of Type I or Type II water, pres
47、entedin D1193.8.3 Concentrated Sodium Hydroxide Solution (0.4 M)In a1-L volumetric flask, dissolve 16 g NaOH in reagent water anddilute to volume.8.4 Dilute Sodium Hydroxide Solution Extraction Fluid(0.04 M)In a 1-L volumetric flask, add 100 mL of 0.4 MNaOH in reagent water and dilute to volume.8.5
48、Sample BottlesSee Section 10.2 for further informa-tion about sample bottles.9. Hazards9.1 WarningBecause of the toxicity of cyanide, greatcare must be exercised in its handling. Acidification of cyanidesolutions produces toxic hydrocyanic acid (HCN). Adequateventilation is necessary when handling c
49、yanide solutions and afume hood should be utilized whenever possible.9.2 WarningMany of the reagents used in these testmethods are highly toxic. These reagents and their solutionsand extracted solids must be disposed of properly.10. Sampling10.1 Obtain a representative sample of the mine rock or soilto be tested by using, where available, ASTM samplingmethods developed for the cyanide processing industry.10.2 Sampling methodology for materials of similar physi-cal form shall be used where no specific methods are available.10.3 Laboratory personnel and field
