1、Designation: E1070 17E1070 17aStandard Test Method forDetermination of Phosphorus in Iron Ores by Phospho-Molybdenum-Blue Spectrophotometry1This standard is issued under the fixed designation E1070; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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. Scope1.1 This test method covers the determination of phosphorus in iron ores, concentrates, and ag
3、glomerates in the range from0.005 % to 1.0 % phosphorus.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This test method has been evaluated in accordance with Practice E1601 and Guide E1763. Unless otherwise noted in t
4、heprecision and bias section, the lower limit in the scope of each method specifies the lowest analyte content that may be analyzedwith acceptable error (defined as a nominal 5 % risk of obtaining a 50 % or larger relative difference in results on the same testsample in two laboratories).1.4 This st
5、andard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international stand
6、ard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Refer
7、enced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE50 Practices forApparatus, Reagents, and Safety Considerations for ChemicalAnalysis of Metals, Ores, and Related MaterialsE60 Pr
8、actice for Analysis of Metals, Ores, and Related Materials by SpectrophotometryE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related MaterialsE877 Practice for Sampling and Sample Preparation of Iron Ores and Related Materials for Determination of ChemicalComposition and Ph
9、ysical PropertiesE882 Guide for Accountability and Quality Control in the Chemical Analysis LaboratoryE1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical MethodE1763 Guide for Interpretation and Use of Results from Interlaboratory Testing of Chemical A
10、nalysis Methods (Withdrawn2015)33. Terminology3.1 DefinitionsFor definitions of terms used in this test method, refer to Terminology E135.4. Summary of Test Method4.1 The sample is fused in a zirconium crucible with sodium peroxide (Na2O2). The melt is dissolved in water and HCl. In asuitable aliquo
11、t, the molybdenum blue complex is formed by the addition of ammonium molybdate-hydrazine sulfate solution. Theabsorbance of the phospho-molybdenum-blue complex is measured at 725 nm.1 This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Relat
12、ed Materials and is the direct responsibility ofSubcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.Current edition approved May 1, 2017Nov. 15, 2017. Published July 2017December 2017. Originally approved in 1985. Last previous edition approved in 20112017 asE1070 11.17. D
13、OI: 10.1520/E1070-17.10.1520/E1070-17A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved ve
14、rsion of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all
15、changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
16、. United States15. Significance and Use5.1 This test method for the analysis of iron ore concentrates and agglomerates is primarily intended as a referee method to testfor compliance with compositional specifications. It is assumed that users of this test method will be trained analysts capable ofpe
17、rforming common laboratory procedures skillfully and safely. It is expected that work will be performed in a properly-equippedlaboratory and that proper waste disposal procedures will be followed.Appropriate quality control practices shall be followed, suchas those described in Guide E882.5.2 The de
18、termination of this element is needed for international trade and primary iron and steel making.6. Interferences6.1 Elements normally found in iron ores do not interfere excepting arsenic giving positive interference (0.01 % As = 0.001 %P).7. Apparatus7.1 Zirconium Crucible, 50 mL capacity.7.2 Spect
19、rophotometerVisible spectrophotometer capable of measuring absorbance at the 725 nm wavelength using a 1-cmpath length cell in accordance with Practice E60.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended th
20、at allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where suchspecifications are available.4 Other grades may be used, provided it is first ascertained that the reagent is of sufficient high purityto permit its use without lessening
21、the accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water conforming toType I or II of Specification D1193. Type III or IV may be used if they effect no measurable change in the blank or sample.8.3 Ammonium Molybdat
22、e Solution (20 g/L)To 500 mL of water, add cautiously and slowly 300 mL of H2SO4 and cool. Add20 g of ammonium molybdate (NH4)6Mo7O244H2O. Stir to dissolve and dilute to 1 L with water.8.4 Fusion BlankDissolve 4 g of Na2O2 in 40 mL of water in a 250-mL beaker. Add 30 mL of HCl. Boil for 2 min. Cool
23、anddilute to 100 mL with water in a volumetric flask. Prepare fresh as needed.8.5 Hydrazine Sulfate (1.5 g/L)Dissolve 0.15 g of hydrazine sulfate NH2NH2H2SO4 in water and dilute to 100 mL withwater. Prepare fresh as needed.8.6 Molybdate (5 g/L) Hydrazine Sulfate (0.15 g/L) SolutionAdd 50 mL of ammon
24、ium molybdate solution (20 g/L) to 100mL of water. Add 20 mL of hydrazine sulfate solution (1.5 g/L) and dilute to 200 mL with water.8.6.1 This solution should be prepared within 30 min of use in a quantity appropriate for the number of tests being made.8.7 Sodium Peroxide (Na2O2)Use caution when us
25、ing peroxide.8.8 Sodium Sulfite Solution (100 g/L)Dissolve 10 g of sodium sulfite (Na2SO3) in water and dilute to 100 mL with water.8.9 Standard Phosphorus SolutionDry anhydrous disodium phosphate (Na2HPO4) at 105 C for 2 h and after desiccation,dissolve 0.2292 g of the reagent in 200 mL of water. D
26、ilute to 1 L with water in a volumetric flask and mix. This solution, A,provides 1 mL = 50 g P. Transfer 10.00 mL of solutionAinto a 50-mL volumetric flask, dilute to mark with water, and mix. Thissolution, B, provides the standard phosphorus solution for calibration 1 mL = 10 g P.9. Hazards9.1 For
27、precautions to be observed in this method, refer to Practices E50.10. Sampling and Sample Preparation10.1 Collect and prepare gross samples in accordance with Practice E877.10.2 Pulverize the laboratory sample to pass a No. 100 (150-m) sieve.NOTE 1To facilitate decomposition, some ores, such as spec
28、ular hematite, require grinding to pass a No. 200 (75-m) sieve.11. Calibration and Standardization11.1 The recommended range of phosphorus content is from 0.005 mg to 0.10 mg phosphorus in 50 mL of color solution usingcell depth of 1 cm.4 Reagent Chemicals, American Chemical Society Specifications,
29、American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.E1070 17a211.2 Into a series of five 150-mL beakers,
30、transfer 10.0 mL of fusion blank solution (8.4) and then transfer (0, 0.50, 2.50) mLof standard B phosphorus solution (8.9); 1.00 mL and 2.00 mL of standardAphosphorus solution (8.9) corresponding to (0, 5, 25,50, and 100) g of phosphorus respectively. To each beaker add 15 mL of sodium sulfite solu
31、tion (8.8). Mix. Bring to a boil. Add20 mL of molybdate-hydrazine sulfate solution (8.6). Bring to a boil. Simmer for 10 min in boiling water bath. Cool. Transfer intoa 50-mL volumetric flask and dilute to the mark with water. Mix. This solution is stable for at least 2 h.11.3 SpectrophotometryAdjus
32、t the spectrophotometer to the initial setting, using water as the reference solution. Whilemaintaining this setting, measure absorbance of the calibration standard and sample solutions at 725 nm in a 1-cm cell.11.4 Preparation of Calibration CurveSubtract the absorbance of the 0-mL phosphorus solut
33、ion from the absorbance of eachcalibration solution and plot the net absorbance against g of phosphorus in the color solution.12. Procedure12.1 Weigh approximately the amount of the prepared sample specified in the following table into a small weighing bottlepreviously dried at 150 C:P Content, %Mas
34、s ofSample, gSampleAliquot, mLFusionBlank, mL0.005 to 0.15 0.300 10.0 None0.15 to 0.50 0.100 10.0 None0.50 to 1.0 0.100 5.0 5.0Dry the contents for 1 h at 105 C to 110 C. Cap the bottle and cool to room temperature in a desiccator. Momentarily releasethe cap to equalize the pressure and weigh the ca
35、pped bottle and test sample to the nearest 0.1 mg. Repeat the drying and weighinguntil there is no further loss of mass. Transfer the test sample into a zirconium crucible and reweigh the capped bottle to the nearest0.1 mg. The difference between the two masses is the mass of test sample taken for a
36、nalysis. Add 2 g of Na2O2 to the crucibleand mix with a dry, stainless steel spatula.NOTE 2As used in this test method (except as related to the term relative standard deviation), “percent or “%” refers to mass fraction (wt/wt) of theform g/100 g.12.2 Fuse over a burner, swirling the crucible until
37、the melt is cherry red and clear. Remove from the heat and swirl until themelt solidifies on the wall of the crucible.12.3 Place the crucible in a 250-mLdry beaker and cool. Cover with a watch glass and add about 10 mLof water to the crucible.After the reaction ceases, transfer the crucible contents
38、 into the beaker, and wash the crucible with water. Add 15 mL of HCl tothe crucible and transfer to the beaker. Rinse the crucible with water and add the rinsings to the beaker. Boil for 2 min. Cool.Transfer the contents and rinsings into a 50-mL volumetric flask. Dilute to volume with water and mix
39、.12.4 Transfer appropriate aliquot of the test solution and fusion blank aliquot (in accordance with 11.2) into a 150-mL beaker.Add 15 mL of sodium sulfite solution (100 g/L). Mix. Bring to a boil. Add 20 mL of molybdate (5 g/L) hydrazine sulfate (0.15g/L) solution. Bring to a boil. Simmer for 10 mi
40、n in a boiling water bath. Cool. Transfer into a 50-mL volumetric flask and diluteto the mark with water. Mix.12.5 Measure absorbance at 725 nm in a 1-cm cell in the same manner as the calibration solutions.13. Calculation13.1 Subtract the absorbance of the 0-mL phosphorus solution from the absorban
41、ce of the test sample solutions. Determine gphosphorus referring to the calibration curve.13.2 Calculate the phosphorus content as follows:Phosphorus,%5S0.005AB3C D (1)TABLE 1 Statistical InformationSample Average Phosphorus Content,% Standard DeviationRelativeStandardDeviation, %Number ofParticipat
42、ingLaboratoriesNumber ofReplicatesJapan 830-1 (0.125)A 0.1270 0.0035 2.75 8 24NBS 690 (0.011)A 0.0085 0.0010 11.76 8 24NIST 690 (0.011)A 0.0085 0.0010 11.76 8 24NBS 692 (0.039)A 0.0393 0.0022 5.61 8 24NIST 692 (0.039)A 0.0393 0.0022 5.61 8 24NBS 693 (0.056)A 0.0554 0.0020 3.61 8 24NIST 693 (0.056)A
43、0.0554 0.0020 3.61 8 24A Certificate ValuePhosphorus content, %.E1070 17a3where:A = g of phosphorus determined,B = sample aliquot in milliliters (12.1), andC = sample mass in grams (12.1).13.3 Rounding of test results obtained using this test method shall be performed in accordance with Practice E29
44、, RoundingMethod, unless an alternative rounding method is specified by the customer or applicable material specification.NOTE 3As used in this test method, “percentage“ or “%“ refers to a mass fraction of the form (wt / wt %) (g / 100 g).14. Precision and Bias514.1 PrecisionTable 1 indicates the pr
45、ecision of the test method between laboratories and comparison with the certifiedreference materials.14.2 BiasThe results obtained by the 8 laboratories on the certified reference iron ores, of varying composition, agree closelywithin narrow limits with the assigned certified phosphorus values, thus
46、 demonstrating absence of any measurable bias.15. Keywords15.1 agglomerates and related materials; concentrates; iron ores; phosphorus contentASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of thi
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