1、Designation: E 738 00 (Reapproved 2005)Standard Test Method forDetermination of Aluminum in Iron Ores and RelatedMaterials by Complexometric Titration1This standard is issued under the fixed designation E 738; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method2covers the determination of aluminumin iron ores, concentrate
3、s, and agglomerates in the concentra-tion range from 0.25 to 5 % aluminum.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 address all of thesafety concerns, if any, associated with its u
4、se. 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:3D 1193 Specification for Reagent WaterE50 Practices for Apparatus, Reagent
5、s, and Safety Precau-tions for Chemical Analysis of MetalsE 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 877 Practice for Sampling and Sample Preparation of IronOres and Related MaterialsE 882 Guide for Accountability and Quality Control in theChemical Ana
6、lysis Laboratory3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology E 135.4. Summary of Test Method4.1 The sample is fused in a zirconium crucible with amixed flux of sodium carbonate and sodium peroxide. Thefused mass is dissolved in dilute hydrochlor
7、ic acid. The R2O3hydroxides are precipitated with ammonia and redissolved inhydrochloric acid. Iron, titanium, and so forth, are removedwith cupferron and chloroform. The aqueous phase is treatedwith nitric and perchloric acids and evaporated to dryness.After dissolving in dilute hydrochloric acid,
8、the solution isfiltered, and the filtrate is treated with an excess of ethylene-diaminetetraacetic acid (EDTA). The excess EDTA is titratedwith a standard zinc solution using xylenol orange indicator.Ammonium fluoride is added to release the EDTA bound toaluminum. This EDTA is then titrated with sta
9、ndard zincsolution, and the percent aluminum is calculated.5. Significance and Use5.1 This test method for the analysis of iron ore concentratesand agglomerates is primarily intended as a referee method totest for compliance with compositional specifications. It isassumed that all who use this test
10、method will be 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 shall be followed, such
11、as those described inGuide E 882.6. Interferences6.1 None of the elements normally found in iron oresinterfere with this test method.7. Apparatus7.1 Zirconium Crucible, 50-mL.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materi
12、als and is the directresponsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-lurgical Materials.Current edition approved Oct. 1, 2005. Published October 2005. Originallyapproved in 1980. Last previous edition approved in 2000 as E 738 00.2Bhargava, O. P., “Complexometric Deter
13、mination of Aluminum in Iron Ore,Sinter, Concentrates, and Agglomerates,” Talanta, Vol 26, 1979, pp. 146 to 148.3For 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 the
14、standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is in
15、tended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.4Other grades may be used,provided it is first ascertained that the reagent is of sufficienthigh purity to permit its use without lesse
16、ning the accuracy ofthe determination.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type II of Specification D 1193.8.3 Ammonium Chloride Solution (10 g/L)Dissolve 10 gof ammonium chloride in water and dilute to 1 L. Add 2 dr
17、ops(0.1 mL) of ammonium hydroxide per 100 mL of solution.8.4 Ammonium Fluoride SolutionDissolve 10 g of ammo-nium fluoride (NH4F) in 100 mL of water in a polyethylenebeaker. Prepare fresh each day.8.5 Ammonium Hydroxide (1 + 1)Mix 1 volume of am-monium hydroxide (NH4OH) with 1 volume of water.8.6 Cu
18、pferron Solution (60 g/L)Dissolve6gofcupferronin 80 mL of cold water, dilute to 100 mL, and filter. Preparefresh as needed.8.7 Ethylenediaminetetraacetic Acid (EDTA) Solution(0.01 mol/L).8.8 Sodium Acetate Buffer SolutionDissolve 136 g ofsodium acetate trihydrate (CH3COONa3H2O) in about 600mL of wat
19、er. Add 7 mL of glacial acetic acid and dilute to 1 L.Store in a polyethylene bottle.8.9 Sodium Carbonate.8.10 Sodium Hydroxide Solution (10 %).8.10.1 Dissolve 100 g of sodium hydroxide (NaOH) inabout 100 mL of water. When dissolution is complete, cool,and dilute to 1 L. Store in a plastic bottle.8.
20、11 Sodium Hydroxide Solution (1 %)Dilute 100 mL of10 % sodium hydroxide solution to 1 L with water.8.12 Sodium Peroxide.8.13 Xylenol Orange IndicatorTriturate 0.1 g xylenolorange with a little water to make a paste. Dilute to 100 mLwith water, filter, and store in an amber-colored glass stopperedbot
21、tle. The solution is stable for 1 week.8.14 Zinc, Standard Solution (0.01 M)Weigh 0.6538 g ofhigh purity (99.99 % zinc) zinc metal into a 125-mL Erlenm-eyer flask. Add 5 mL of water followed by 2 to 3 mL of nitricacid. Cover the flask and simmer. If the reaction subsidesleaving undissolved metal, ad
22、d 2-mL increments of waterfollowed by simmering until complete solution is obtained.Add 50 mL of water and gently boil for 2 min. Cool. Bydropwise addition of sodium hydroxide solution (1 %), adjustthe pH to 4. Dilute to 1 L with water in a volumetric flask.9. Hazards9.1 For precautions to be observ
23、ed in this method, refer toPractices E 50.10. Sampling and Sample Preparation10.1 Sample the material in accordance with Practice E 877.10.2 Pulverize the laboratory sample to pass a No. 100(150-m sieve).NOTE 1To facilitate decomposition, some ores, such as specularhematite, require grinding to pass
24、 a No. 200 (75-m) sieve.11. Procedure11.1 Select and weigh a test sample in accordance with thefollowing:Aluminum, % Test Sample Weight, gTolerance in Test SampleWeight, mg0.25 to 1 0.3 51to2 0.2 52to5 0.1 5Transfer the prepared sample to a small weighing bottlepreviously dried at about 105C. Dry th
25、e bottle and contentsfor 1 h at 105 to 110C. Cap the bottle and cool to roomtemperature in a desiccator. Momentarily release the cap toequalize the pressure and weigh the capped bottle and sampleto the nearest 0.1 mg. Repeat the drying and weighing untilthere is no further weight loss. Transfer the
26、test sample to a dry,zirconium crucible containing 0.5 g of sodium carbonate andreweigh the capped bottle to the nearest 0.1 mg. The differencebetween the two weights is the weight of the test sample takenfor analysis. Add 2 g of sodium peroxide to the crucible andmix with a dry, stainless steel spa
27、tula.11.2 Fuse over a burner, swirling the crucible until the meltis cherry red and clear. Remove from the heat and swirl untilthe melt solidifies on the wall of the crucible.11.3 Place the crucible in a 250-mL dry beaker and cool.Cover with a watchglass and add about 10 mL of water to thecrucible.
28、After the reaction ceases, transfer the crucible con-tents into the beaker and wash the crucible with water. Add 20mL of HCl (1 + 1) by way of the crucible into the beaker. Rinsethe crucible with water and add rinsings to the beaker. Dilute toabout 70 mL with water and heat to boiling.11.4 Remove fr
29、om heat and add NH4OH (1 + 1) dropwiseuntil the precipitation of the hydroxides is complete (pH 6 to7). Boil for 1 min and immediately filter through a medium-textured paper. Wash five times with hot ammonium chloridesolution (10 g/L). Then wash five times with hot water. Discardthe filtrate. Place
30、the unfolded filter paper on the inner wall ofthe original beaker and remove the precipitate from the paperwith a fine jet of hot water. Then wash the filter paper with 25mL of hot HCl (1 + 1) and finally with a jet of hot water.Discard the filter paper, cover the beaker with a watchglass,and bring
31、the contents to a boil. Cool and adjust the volume to50 mL using water. Cool to about 10C.11.5 Transfer the test solution to a cold 250-mL separatoryfunnel. Rinse the beaker with 25 mL of cold water and add tothe separatory funnel. Add 25 mL of cold cupferron solutionand mix. Add 30 mL of chloroform
32、 and shake vigorously for 1min. Let the layers separate and draw off the organic phase and4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standard
33、s for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.E 738 00 (2005)2discard. Wash the aqueous layer with two successive additionsof 20 mL of chloroform, again discarding the orga
34、nic phase.Wipe the stem of the separatory funnel with a filter paper wick.11.5.1 Drain the aqueous phase into a 250-mL beaker,rinsing with 5 mL of HCl (1 + 5). Boil for a few minutes andremove from the heat. Add 5 mL of HNO3and 10 mL ofHClO4. Cover with a ribbed cover glass and evaporate nearlyto dr
35、yness. Remove from the heat and add 10 mL of HCl(1 + 1). Heat to dissolve the salts, add 50 mL of water, andbring to a boil. Filter through a medium-textured filter paperand wash several times with hot water.11.6 Cool and add 25.0 mL of EDTA solution. Using a pHmeter, adjust the pH to 2.5 by the dro
36、pwise addition of NaOHsolution (10 %) then to pH 4.0 by the dropwise addition ofNaOH solution (1 %). Dilute to 100 mL with water, cover thebeaker, and boil gently for 10 min. Cool and add 15 mL ofsodium acetate buffer solution and 7 drops of xylenol orangeindicator solution. Stir using a magnetic st
37、irrer and titrate withzinc standard solution to a persistent (30 s) pink end point.11.7 Add 10 mL of ammonium fluoride solution and boilgently for 10 min. Cool, add 2 to 3 drops of xylenol orangeindicator solution, and titrate the liberated EDTA with zincstandard solution to a persistent (30 s) pink
38、 end point.12. Calculation12.1 Calculate the percentage of aluminum as follows:Aluminum dry basis!,%5 0.02698 A/B (1)where:A = millilitres of zinc standard solution used in 11.7, andB = grams of sample used.13. Precision and Bias513.1 PrecisionTable 1 indicates the precision of the testmethod betwee
39、n laboratories.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 this test method are encouraged to employ acceptedreference materials, if available, and to judge the bias of
40、themethod from the difference between the accepted value for thealuminum content and the mean value from interlaboratorytesting of the reference material.14. Keywords14.1 agglomerates and related materials; aluminum content;concentrates; iron oresASTM International takes no position respecting the v
41、alidity of any patent rights asserted in 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 s
42、ubject 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 ASTM International Headq
43、uarters. 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.This stan
44、dard 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), 610-832-9555 (fax), or se
45、rviceastm.org (e-mail); or through the ASTM website(www.astm.org).5Supporting data giving the results of cooperative testing are available fromASTM International Headquarters. Request RR: E16-1002.TABLE 1 Statistical InformationIron OreAverageConcen-tration, %RelativeStandardDeviation,A%Number ofPar
46、ticipatingLaboratoriesNumberof Determi-nationsMarcona 0.362 3.04 23 67Krivoj 0.661 2.72 23 67BCS 377 1.76 1.82 23 67Monette 2.34 1.79 23 66BCS 303 3.51 1.25 23 69Phillipine Iron Sand 1.44 1.25 23 68ACalculate the relative standard deviation, n, in this test method as follows:n5100/ X!=(d2/n 2 1!where:X= average concentration, %,d = difference of the determination from the mean, andn = number of determinations.E 738 00 (2005)3
