1、Designation: E247 01 (Reapproved 2015)1Standard Test Method forDetermination of Silica in Manganese Ores, Iron Ores, andRelated Materials by Gravimetry1This standard is issued under the fixed designation E247; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the 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.1NOTEEditorially corrected 1.1 and Table 1 in November 2015.1. Scope1.1 This test method co
3、vers the determination of silica iniron ores, iron ore concentrates and agglomerates, and manga-nese ore in the range from 0.5 % to 15 %.1.2 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 a
4、ddress 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 use.2. Referenced Documents2.1 ASTM Standards:2D1193 Speci
5、fication for Reagent WaterE50 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 MaterialsE691 Practice for Conducting an Interlaboratory Study toDeter
6、mine the Precision of a Test MethodE877 Practice for Sampling and Sample Preparation of IronOres and Related Materials for Determination of Chemi-cal Composition and Physical PropertiesE882 Guide for Accountability and Quality Control in theChemical Analysis Laboratory3. Terminology3.1 DefinitionsFo
7、r definitions of terms used in this testmethod, refer to Terminology E135.4. Summary of Test Method4.1 The sample is fused with sodium peroxide in a zirco-nium crucible. The melt is leached with water and dissolved inHCl. Silica is separated by double dehydration with HClO4.The two precipitates are
8、combined, ignited, and weighed. Thesilica is volatilized by treatment with HF and H2SO4and theresidue weighed.5. Significance and Use5.1 This test method is intended to be used for compliancewith compositional specifications for silica content. It isassumed that all who use these procedures will be
9、trainedanalysts capable of performing common laboratory proceduresskillfully and safely. It is expected that work will be performedin a properly equipped laboratory and that proper wastedisposal procedures will be followed. Appropriate qualitycontrol practices must be followed such as those describe
10、d inGuide E882.6. Interferences6.1 This test method is written for iron and manganese orescontaining less than 0.25 % of fluorine. None of the elementsnormally found in iron ores or in manganese ores interfere withthis test method.7. Apparatus7.1 Zirconium Crucible (50-mL capacity).7.2 Platinum Filt
11、er Cone.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society where1This test method is under
12、the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the directresponsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-lurgical Materials.Current edition approved Nov. 15, 2015. Published December 2015. Originallyapproved
13、 in 1964. Last previous edition approved in 2010 as E247 01 (2010).DOI: 10.1520/E0247-01R15E01.2For 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 Documen
14、t Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1such specification are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficienthigh purity to permit its u
15、se without lessening the accuracy ofthe determination.8.2 Purity of WaterUnless otherwise indicated, refer-ences to water shall be understood to mean reagent water asdefined by Type II of Specification D1193.8.3 Hydrochloric Acid (sp gr 1.19)Concentrated HCl.8.4 Hydrochloric Acid (1 + 49)Mix 1 volum
16、e of concen-trated HCl (sp gr 1.19) with 49 volumes of water.8.5 Hydrofluoric Acid (48 %)Concentrated HF.8.6 Perchloric Acid (70 %)HClO4.8.7 Sodium Peroxide PowderNa2O2.8.8 Sulfuric Acid (1 + 1)Carefully pour one volume ofconcentrated H2SO4, sp gr 1.84, into one volume of water.9. Hazards9.1 For pre
17、cautions to be observed in this method, refer toPractices E50.10. Sampling and Sample Preparation10.1 SamplingThe gross sample shall be collected andprepared in accordance with Practice E877.10.2 Sample PreparationThe laboratory sample shall bepulverized to pass a No. 100 (150-m) sieve.NOTE 1To faci
18、litate decomposition, some ores, such as specularhematite, require grinding to pass a No. 200 (75-m) sieve.10.3 Sample WeightWeigh approximately (within6 25 mg) an amount of test sample specified as following:Content of Silica, % Weight of Test Sample, gLess than 2 1.02 and over 0.511. Procedure11.1
19、 Transfer the test sample to a small, dry weighing bottleand place in a drying oven. Dry iron ore samples at 110 C andmanganese ore samples at 120 C for 1 h. Cap the bottle andcool to room temperature in a desiccator. Momentarily releasethe cap to equalize pressure and weigh the capped bottle to the
20、nearest 0.1 mg. Repeat the drying and weighing until there isno further weight loss. Transfer the test sample to a zirconiumcrucible and reweigh the capped bottle to the nearest 0.1 mg.The difference between the two weights is the weight of the testsample.Add 4 g of sodium peroxide into the crucible
21、. Mix witha stainless steel spatula.11.2 Fuse the contents over a low flame on a Meker burner,swirling the crucible. When the contents begin to melt, increasethe heat to cherry red. Swirl until a clear melt solidifies evenlyon the sides of the crucible. Cool for 1 min to 2 min and placeinto a 250-mL
22、 beaker. Cover with a watchglass. Cautiously add10 mL to 15 mL of water into the crucible. When the reactionceases, empty the crucible contents and crucible rinsings intothe beaker. Add 25 mL HCl by means of the crucible. Finally,rinse and police crucible with water and add rinsings to thebeaker. He
23、at to a boil to obtain a complete and clear solution.Cool for 1 min to 2 min. Add 25 mL of HClO4. Cover with awatchglass and heat to dense white fumes in the HClO4fumehood. Fume for 15 min to 20 min. Cool for 1 min to 2 min.Add50 mL of water containing 2 mL HCl (8.3) and heat thecontents to dissolve
24、 soluble salts. Filter through a fine-texturedpaper with the aid of paper pulp and a platinum filter coneusing suction. Wash filter five times with hot HCl (1 + 49) (8.4)and then ten times with hot water, to remove all perchlorates(see Note 2). Reserve the filtrate. Transfer filter paper andresidue
25、to a platinum crucible.NOTE 2The residue must be washed free of perchlorates to preventpossible loss of residue by deflagration during the ignition.11.3 Add 10 mL of HClO4to the reserved filtrate. Coverwith a watchglass and take to dense white fumes and continuefuming for 15 min to 20 min. Cool for
26、1 min to 2 min. Add50 mL of water containing 2 mL of HCl (8.3). Heat thecontents to dissolve soluble salts. Filter through a fine-texturedpaper with the aid of paper pulp and a platinum cone usingsuction. Wash five times with hot HCl (1 + 49) (8.4) and thenten times with hot water (Note 2). Combine
27、the filter andresidue with the reserved filter paper and residue in theplatinum crucible.11.4 Ignite crucible and contents at 500 C for 1 h and thenat 1000 C for 30 min. Cool in a desiccator. After 20 min,weigh.11.5 Add six drops of H2SO4(1+1)(8.8) to moisten thecontents of the crucible. Add 5 mL of
28、 HF. Cautiously andslowly heat to the absence of sulfur trioxide (SO3) fumes.Ignite the residue in a muffle furnace at 1000 C for 10 min.Cool in a desiccator. After 20 min, weigh. The difference inweight is the weight of the silica.12. Blank Determination12.1 Perform a blank determination using the
29、same amountof reagents and performing the same operations described inthe test procedure.13. Calculation13.1 Calculate the percentage of silica as follows:Silica, % 5 100FA 2 B!CGwhere:A = silica in test sample, g,B = silica in blank, g, andC = test sample weight, g.14. Precision and Bias414.1 Preci
30、sionTable 1 indicates the precision of the testmethod as determined by Practice E691, but not extended to3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC, www.chemistry.org. For suggestions on thetesting of reagents not listed by the American Che
31、mical Society, see the UnitedStates Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention,Inc. (USPC), Rockville, MD, http:/www.usp.org.4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:E16-1005.E247 01 (Reapproved 20
32、15)12obtaining either the repeatability or reproducibility statisticsince there were only duplicate determinations made by threecooperating laboratories. (Although one laboratory made qua-druplicate analyses on the manganese ore, it was treated as ifthey were only duplicates.)14.2 BiasThere was no s
33、ignificant bias in the determina-tions using samples that were all National Institute of Stan-dards and Technology (NIST) certified reference materials.15. Keywords15.1 agglomerates; analytical procedures; concentrates; gra-vimetric silica; iron ore; manganese ore; silicaASTM International takes no
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35、bility.This standard is subject to revision at any time by the responsible 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
36、 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 addr
37、ess shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone),
38、610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Statistical SummaryASampleBCertified%Av
39、erageDetermination, %Standard DeviationWithin-LaboratoryBetween-LaboratoriesIron OreNIST 692 10.14 10.10 0.038 0.080NIST 27F 4.17 4.13 0.036 0.052NIST 693 3.87 3.86 0.044 0.045NIST 690 3.71 3.66 0.029 0.064Manganese OreNIST 25C 2.36 2.34 0.036 0.074Pooled standard deviationsC0.037 0.064ACalculations based on Practice E691. Since there were only three cooperatinglaboratories, no projection is made to determine repeatability or reproducibilityvalues.BEach concentration represents a different kind of iron ore.CRoot mean square of individual standard deviations.E247 01 (Reapproved 2015)13
