1、Designation: E465 11 (Reapproved 2017)Standard Test Methods forDetermination of Manganese (IV) in Manganese Ores byRedox Titrimetry1This standard is issued under the fixed designation E465; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, 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. Scope1.1 These test methods cover the determination of manga-nese dioxide in amounts commonly found in manga
3、nese ore.The determination measures the amount of manganese (IV)present in the sample. The result may be expressed as availableoxygen or as manganese dioxide. The following test methodsare included and may be used interchangeably:SectionsTest Method A (Ferrous Ammonium Sulfate) 913Test Method B (Per
4、iodate (Sodium Oxalate) 14181.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of thi
5、s standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principl
6、es for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data toDet
7、ermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE882 Guide for Accountability and Quality Control
8、 in theChemical Analysis Laboratory3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology E135.4. Significance and Use4.1 This test method is intended to be used for compliancewith compositional specifications for manganese dioxide con-tent in manganese o
9、res. It is assumed that all who use theseprocedures will be trained analysts capable of performingcommon laboratory procedures skillfully and safely. It isexpected that work will be performed in a properly equippedlaboratory and that proper waste disposal procedures will befollowed. Appropriate qual
10、ity control practices shall befollowed, such as those described in Guide E882.5. Interferences5.1 The elements ordinarily present in manganese ores donot interfere in either test method.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise
11、 indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficienthigh purity to permit i
12、ts use without lessening the accuracy ofthe determination.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conforming1These test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Ma
13、terials and are the directresponsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-lurgical Materials.Current edition approved May 1, 2017. Published June 2017. Originallyapproved in 1972. Last previous edition approved in 2011 as E465 11. DOI:10.1520/E0465-11R17.2For reference
14、d 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.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemi
15、cal Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see the United States Pharmacopeia andNational Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, We
16、st 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 and Recommendations issued by the World T
17、rade Organization Technical Barriers to Trade (TBT) Committee.1to Type I or II of Specification D1193. Type III or IV may beused if they effect no measurable change in the blank orsample.7. Hazards7.1 For precautions to be observed in these methods, refer toPractice E50.8. Sampling and Sample Prepar
18、ation8.1 The sample shall pass a No. 100 (150-m) sieve.TEST METHOD AFERROUS AMMONIUMSULFATE METHOD9. Summary of Test Method9.1 The test sample is dissolved in an excess of ferrousammonium sulfate solution. The manganese dioxide reactswith an equivalent amount of ferrous iron. The excess ferrousiron
19、is titrated with standard potassium dichromate solutionusing sodium diphenylamine sulfonate as an indicator.10. Reagents and Materials10.1 Ferrous Ammonium Sulfate Solution (45 g/L)Dissolve 45 g of ferrous ammonium sulfateFe(NH4)2(SO4)26H2O in 1 L of H2SO4, (1 + 7).10.2 Potassium Dichromate, Standar
20、d Solution (0.1 N)10.2.1 Dissolve 4.9035 g of Primary Standard Grade potas-sium dichromate (K2Cr2O7) in water, transfer to a 1-L volu-metric flask, dilute to volume, and mix.10.3 Sodium Diphenylamine Sulfonate Indicator Solution,(2 g/L).10.3.1 Dissolve 0.20 g of sodium diphenylamine sulfonatein 100
21、mL of water. Store in a dark-colored bottle.11. Procedure11.1 Transfer approximately 0.4 g of test sample to a small,dry weighing bottle and place into a drying oven. Dry at 120 Cfor 1 h, cap the bottle, and cool to room temperature in adesiccator. Momentarily release the cap to equalize the pres-su
22、re and weigh the capped bottle to the nearest 0.1 mg. Repeatthe drying and weighing until there is no further mass loss.Transfer the test sample to a dry 300-mL Erlenmeyer flask andreweigh the capped bottle to the nearest 0.1 mg. The differenceis the mass of the test sample.11.2 Add 50.0 mL of the f
23、errous ammonium sulfatesolution, plus an additional 10.0 mL for each 0.1 g of MnO2present, to the flask. Close the flask with a stopper equippedwith inlet and outlet tubes. Pass carbon dioxide (CO2) throughthe flask.11.3 Heat the flask moderately and shake intermittently untilthe ore is decomposed.1
24、1.4 Cool the contents of the flask while maintaining theflow of carbon dioxide.11.5 Unstopper the flask, add 2 mL of sodium diphenylam-ine sulfonate indicator solution, and 10 mL of H3PO4. Dilute to150 mL with cold water (from which the air was removed byboiling) and titrate the excess ferrous ammon
25、ium sulfate withstandard K2Cr2O7solution to a permanent purple end point.11.6 The correlation between the solutions of ferrous am-monium sulfate and potassium dichromate is established undertest conditions. For this purpose, transfer into a flask the sameamount of ferrous ammonium sulfate solution u
26、sed to dissolvethe ore, and proceed as directed in 11.3.12. Calculation12.1 Calculate the manganese dioxide content as follows:Manganese dioxide, % 5A 2 B! 3 C 34.3465#D(1)where:A = millilitres of standard K2Cr2O7solution used to estab-lish the correlation in 11.6,B = millilitres of standard K2Cr2O7
27、solution required totitrate the excess of ferrous ammonium sulfate in thesample solution,C = the normality of standard K2Cr2O7solution, andD = grams of test sample used.NOTE 1As used in this test method (except as related to the termrelative standard deviation), “percent” or “%” refers to mass fract
28、ion(wt/wt) of the form g/100g.12.2 Rounding of test results obtained using this test methodshall be performed in accordance with Practice E29, RoundingMethod, unless an alternative rounding method is specified bythe customer or applicable material specification.13. Precision and Bias13.1 PrecisionTa
29、ble 1 indicates the precision of the testmethod between laboratories.13.2 BiasNo information on the bias of this test method isknown. Accepted reference materials may have not beenincluded in the materials used in the interlaboratory study.Users of the method are encouraged to employ acceptedreferen
30、ce materials, if available, and to judge the bias of themethod from the difference between the accepted value for themanganese dioxide content and the mean value from interlabo-ratory testing of the reference material.TEST METHOD BSODIUM OXALATE METHOD14. Summary of Test Method14.1 The test sample i
31、s dissolved in H2SO4in the presenceof sodium oxalate. The manganese dioxide reacts with anequivalent amount of oxalate. The excess sodium oxalate istitrated with a standard solution of potassium permanganate.TABLE 1 Statistical InformationSample MethodAverageManganeseDioxideContent,%RelativeStandard
32、Deviation,%Number ofDetermin-ationsNumber ofParticipatingLaboratories1 A 40.87 0.54 35 72 A 70.23 0.47 29 61 B 40.90 0.46 29 82 B 70.32 0.38 29 8E465 11 (2017)215. Reagents and Materials15.1 1,10 Phenanthroline Indicator Solution (0.025 M)15.1.1 Dissolve 1.485 g of 1,10-phenanthroline monohy-drate a
33、nd 0.695 g of ferrous sulfate (FeSO47 H2O) in 50 mLof water. Dilute to 100 mL.15.2 Potassium Permanganate, Standard Solution (0.1 N)15.2.1 PreparationDissolve 3.2 g of potassium perman-ganate (KMnO4) in 1 L of water. Let stand in the dark for twoweeks. Filter, without washing, through a Gooch crucib
34、le or afine porosity fritted-glass crucible. Avoid contact with rubberor other organic material. Store in a dark-colored glass-stoppered bottle.15.2.2 StandardizationDry a portion of the primary stan-dard sodium oxalate at 105 C. Transfer 0.3000 g of the sodiumoxalate to a 600-mL beaker. Add 250 mL
35、of H2SO4(5 + 95),previously boiled for 10 min to 15 min and then cooled to 27C 6 3 C, and stir until the oxalate has dissolved. Add (39 to40) mL (Note 2) of the KMnO4solution, at a rate of (25 to 35)mL/min, while stirring slowly. Let stand until the pink colordisappears (about 45 s) (Note 3). Heat t
36、o 55 C to 60 C andcomplete the titration by adding KMnO4solution until a faintpink color persists for 30 s. Add the last (0.5 to 1) mLdropwise, allowing each drop to become decolorized beforeadding the next drop. To determine the blank: titrate 250 mL ofH2SO4(5 + 95), treated as above, with KMnO4sol
37、ution to afaint pink color. The blank correction is usually equivalent to0.03 mL to 0.05 mL.NOTE 2A 0.3000-g portion of sodium oxalate requires 44.77 mL ofKMnO4solution (0.1 N)(10.2).NOTE 3If the KMnO4solution is too strong, the pink color will fadeat this point; begin again, adding a few millilitre
38、s less of the KMnO4solution.15.3 Sodium OxalateDry the reagent for2hat105Cprior to use.16. Procedure16.1 Transfer approximately 0.4 g of test sample to a small,dry weighing bottle and place in a drying oven. Dry at 120 Cfor 1 h, cap the bottle, and cool to room temperature in adesiccator. Momentaril
39、y release the cap to equalize pressureand weigh the capped bottle to the nearest 0.1 mg. Repeat thedrying and weighing until there is no further mass loss.Transfer the test sample to a dry 300-mL Erlenmeyer flask andreweigh the capped bottle to the nearest 0.1 mg. The differenceis the mass of the sa
40、mple.16.2 Add 100 mL of H2SO4(1 + 9) and 0.8000 g of sodiumoxalate to the flask.16.3 Cover the flask with a small cover glass and heat on asteam bath to decompose the ore. Swirl the flask occasionallyand continue heating until all dark colored particles havedisappeared.16.4 When decomposition is com
41、plete, rinse the contents ofthe flask into a 600-mL beaker and adjust the volume to about200 mL with hot water. Add 2 drops to 3 drops of the 1,10phenanthroline indicator solution and titrate the hot solution(60 C to 70 C) with the standard KMnO4solution (Note 4).At the end point, the color will cha
42、nge from pink to green.NOTE 4The titration may be performed without using the indicator byobserving a pink end point due to excess potassium permanganate.16.5 The correlation between the sodium oxalate and thestandard permanganate solution is established under test con-ditions. For this purpose, tra
43、nsfer 0.8000 g of sodium oxalateand 100 mL of H2SO4(1 + 9) to a 300-mL Erlenmeyer flask.Proceed as directed in 16.3.17. Calculation17.1 Calculate the manganese dioxide content as follows:Manganese dioxide, % 5A 2 B! 3 C 34.3465#D(2)where:A = millilitres of standard KMnO4solution used to titrate0.800
44、0 g of sodium oxalate,B = millilitres of standard KMnO4solution used to titratethe excess of sodium oxalate in the sample solution,C = normality of the standard KMnO4solution, andD = grams of sample used.17.2 Rounding of test results obtained using this test methodshall be performed in accordance wi
45、th Practice E29, RoundingMethod, unless an alternative rounding method is specified bythe customer or applicable material specification.18. Precision and Bias18.1 PrecisionTable 1 indicates the precision of the testmethod between laboratories.18.2 BiasNo information on the bias of this test method i
46、sknown. Accepted reference materials may have not beenincluded in the materials used in the interlaboratory study.Users of the method are encouraged to employ acceptedreference materials, if available, and to judge the bias of themethod from the difference between the accepted value for themanganese
47、 dioxide content of the reference material and themean value from interlaboratory testing of the referencematerial.19. Keywords19.1 manganese dioxide content; manganese ores ; redoxtitrimetryE465 11 (2017)3ASTM International takes no position respecting the validity of any patent rights asserted in
48、connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the res
49、ponsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below
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