1、Designation: E 878 01 (Reapproved 2005)Standard Test Method forDetermination of Titanium in Iron Ores and RelatedMaterials by Diantipyrylmethane Ultraviolet Spectrometry1This standard is issued under the fixed designation E 878; the number immediately following the designation indicates the year ofo
2、riginal adoption or, 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 method covers the determination of titanium iniro
3、n ores, concentrates, and agglomerates in the concentrationrange from 0.01 to 6.0 % titanium.1.2 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 prac
4、tices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE 135 Terminolog
5、y 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 Analysis Laboratory3. Terminology3.1 For definitions of terms used in this te
6、st method, refer toTerminology E 135.4. Summary of Test Method4.1 The sample is decomposed by treatment with hydro-chloric, nitric, and sulfuric acids, or by sintering with sodiumperoxide, or by fusion with sodium tetraborate and sodiumcarbonate. Iron is reduced in an acid medium with ascorbicacid,
7、the color is developed with diantipyrylmethane, and theabsorbance is measured at approximately 385 nm.5. Significance and Use5.1 This test method is intended to be used for compliancewith compositional specifications for titanium content. It isassumed that all who use these procedures will be traine
8、danalysts 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 described inGu
9、ide E 882.6. Interferences6.1 None of the elements normally found in iron oresinterfere.7. Reagents and Materials7.1 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 onAnaly
10、tical 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 its use without lessening the accuracy ofthe determination.7.2 Purity of WaterUnless otherwise indi
11、cated, referencesto water shall be understood to mean reagent water as definedby Type I of Specification D 1193.7.3 Ascorbic Acid Solution (10 g/100 mL) (C6H8O6)Dissolve 10 g of ascorbic acid (C6H8O6) in water and dilute to100 mL. Prepare fresh as needed.7.4 Diantipyrylmethane Solution (15 g/L) C23H
12、24O2N4H2ODissolve 15 g of the reagent in about 300 mL of water1This test method is under 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 Mater
13、ials.Current edition approved May 1, 2005. Published June 2005. Originallyapproved in 1982. Last previous edition approved in 2001 as E 878 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
14、lume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for L
15、aboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.and 30 mL of (H2SO
16、4) (1 + 1) (7.10) and dilute to 1 L withwater. If a residue remains, filter and store the filtrate in abrown bottle.7.5 Ferric Ammonium Sulfate (100 g/L)Dissolve 100 g offerric ammonium sulfate (Fe2(SO4)3(NH4)2SO4in 800 mL ofwater containing 5 mL of H2SO4(1+1)(7.11) and dilute to 1L with water.7.6 H
17、ydrochloric Acid (1 + 1)Mix 1 volume of concen-trated hydrochloric acid (HCl) with 1 volume of water.7.7 Hydrochloric Acid (1 + 4)Mix 1 volume HCl with 4volumes of water.7.8 Potassium Pyrosulfate (K2S2O7).7.9 Sodium Tetraborate (Anhydrous) (Na2B4O7)Dry thecommercial sodium tetraborate at 60 to 70C,
18、then at 160C,and finally calcine at 400C.7.10 Sodium Tetraborate/Sodium Carbonate (Na2B4O7/Na2CO3) Fusion Mixture Mix 1 part of Na2B4O7and 1 partof Na2CO3and store in an airtight container.7.11 Sulfuric Acid (1 + 1)Carefully pour 1 volume ofconcentrated sulfuric acid (H2SO4) into 1 volume of water.7
19、.12 Sulfuric Acid (1 + 9)Carefully pour 1 volume ofH2SO4into 9 volumes of water.7.13 Sulfuric Acid (2 + 98)Carefully pour 2 volumes ofH2SO4into 98 volumes of water.7.14 Standard Titanium Solution:7.14.1 Solution A (1 mL = 0.1 mg Ti)Transfer 0.1670 g ofTiO2(previously calcined at 900C) to a platinum
20、crucible, add3to4gofK2S2O7, cover, and fuse at a temperature of 600Cuntil a clear melt is obtained. Place the cooled crucible andcover in a 250-mL beaker, add 50 to 60 mL of H2SO4(1+9)(7.12), and heat to dissolve the melt. Wash crucible and coverwith H2SO4(1+9)(7.12) and remove, adding the washings
21、tothe 250-mL beaker. Transfer the solution of a 1-L volumetricflask, dilute to volume with H2SO4(1+9)(7.12), and mix.7.14.2 Solution B (1 mL = 0.02 mg Ti)Transfer 50.0 mLof standard titanium Solution A to a 250-mL volumetric flask,dilute to volume with H2SO4(1+9)(7.12), and mix.8. Hazards8.1 For pre
22、cautions to be observed in this test method, referto Practices E50.9. Sampling and Sample Preparation9.1 SamplingThe gross sample shall be collected andprepared in accordance with Practice E 877.9.2 Sample PreparationPulverize the laboratory sampleto pass a No. 100 (150-m) sieve.NOTE 1To facilitate
23、decomposition, some ores such as specularhematite require grinding to pass a No. 200 (75-m) sieve.10.4.10. ProcedureNOTE 2If the procedure is based on acid decomposition, use steps in10.1. If the procedure is based on alkaline sintering, use steps in 10.2.Ifthe procedure is based on alkaline fusion,
24、 use steps in 10.3.10.1 Acid Decomposition:10.1.1 Weigh approximately the amount of the test samplespecified in the table below into a small weighing bottlepreviously dried at 150C.Ti content, %Weight of testportion, gAmount ofsulfuric acidto be addedin 9.1, mLAliquot,mL0.010.1 1.0 20 200.10.3 1.0 2
25、0 100.31.0 0.5 10 51.06.0 0.1 10 5Dry the bottle and contents for1hat105to110C. Cap thebottle and cool to room temperature in a desiccator. Momen-tarily release the cap to equalize the pressure and weigh thecapped bottle and sample to the nearest 0.1 mg. Repeat thedrying and weighing until there is
26、no further weight loss.Transfer the test sample to a 250-mL beaker and reweigh thecapped bottle to the nearest 0.1 mg. The difference between thetwo weights is the weight of the test sample taken for analysis.10.1.2 Carry a reagent blank through all steps of theprocedure, starting with 10.1.3.10.1.3
27、 Decomposition of SampleMoisten the test samplewith a few milliliters of water, add 30 mL of hydrochloric acid,cover, and digest below the boiling point until no further attackis apparent.Add 5 mL of nitric acid and 10 to 20 mL of sulfuricacid (see amounts specified in 10.1.1) evaporate slowly tofum
28、es of H2SO4, then heat strongly for 10 min. Allow thesolution to cool, add slowly 50 mL of water and 20 mL ofhydrochloric acid, and warm until soluble salts are in solution.10.1.4 Filter on a fine-textured filter paper and collect thefiltrate in a 250-mL beaker. Transfer the residue quantitativelyto
29、 the filter paper and wash it two or three times with hot dilutesulfuric acid (2+98) (7.13) and two or three times with hotwater. Reserve the filtrate.10.1.5 Treatment of Insoluble Matter Ignite the paper andresidue in a platinum crucible. Cool, moisten with severaldrops of water, add 3 or 4 drops o
30、f dilute sulfuric acid (1+1)(7.11) and 10 mL of hydrofluoric acid. Evaporate slowly toexpel silica and excess of sulfuric acid. Cool, add to the residueabout2gofpotassium pyrosulfate, cover the crucible, and fuseover a burner (approximately 500C) until a clear melt isobtained.10.1.6 Dissolve the coo
31、l melt in the reserved filtrate from10.1.4, remove, and wash the crucible and cover, adding thewashings to the 250-mL beaker. Transfer the solution to a200-mL volumetric flask, dilute to volume, and mix. Continuein accordance with 10.4.10.2 Alkaline Sintering Decomposition:10.2.1 Transfer a sample w
32、eight in accordance with thetable in 10.1.1 to a dried weighing bottle and dry the testsample as described in 10.1.1. Finally transfer the test sampleto a 40-mL nickel crucible.10.2.2 Carry a reagent blank through all steps of theprocedure starting with 10.2.3.10.2.3 Add3gofsodium peroxide and mix u
33、sing aplatinum or nickel spatula. Place the crucible for severalminutes at the entrance of a muffle furnace set at 400C, thenplace it inside the furnace for about 1 h, for sintering. Removethe crucible and allow to cool.10.2.4 Transfer the sintered mass to a 250-mLbeaker, cover,and add about 75 mL o
34、f water. Wash the crucible once withwater and once with dilute HCl (1 + 4) (7.7), adding theE 878 01 (2005)2washings to the beaker. Acidify carefully with 30 mL ofconcentrated HCl, cover the beaker, and heat gently until aclear solution is obtained. Add 20 mL of dilute H2SO4(1+1)(7.11) and evaporate
35、 slowly to fumes of H2SO4; then heatstrongly for 10 min. Allow the solution to cool, add slowly 50mL of water and 20 mL of concentrated HCl, and warm untilsoluble salts are in solution.10.2.5 Continue as described in 10.1.4-10.1.6. Finally carryout spectrophotometric measurements as described in 10.
36、4.10.3 Alkaline Fusion Decomposition:10.3.1 Transfer a test sample weight in accordance with thetable in 10.1.1 to a dried weighing bottle and dry the sampleportion as described in 10.1.1. Finally transfer the sample to aplatinum crucible.10.3.2 Carry a reagent blank through all steps of theprocedur
37、e starting with 10.3.3.10.3.3 Add5goffusion mixture (7.9) and mix, using aplatinum or nickel spatula. Cover the crucible and heat in amuffle furnace, first gently at 600C and finally for 10 min at1000 to 1050C. Remove the crucible and swirl cautiously tocause the cooling melt to solidify in a thin l
38、ayer on the walls ofthe crucible.10.3.4 Place the cooled crucible and cover in a 250-mLbeaker and add 100 mL of dilute hydrochloric acid (1 + 4)(7.7). Heat gently to dissolve the melt, remove, and wash thecrucible, cover, and police adding the washing to the 250-mLbeaker.10.3.5 Transfer the solution
39、 to a 200-mL volumetric flask,dilute to volume, and mix. Continue in accordance with10.4 Preparation of Test Solution for SpectrophotometricMeasurementsTransfer with the help of pipet, an aliquot ofthe test solution and the blank solution in accordance with thetable in 10.1 and transfer into 100-mL
40、volumetric flasks. Add5 mL of ferric ammonium sulfate solution (7.5), and 10 mL ofascorbic acid solution (7.3), and mix. Add 15 mL of dilutehydrochloric acid (1 + 1) (7.6) and 30 mL of diantipyryl-methane solution (7.4), dilute to volume, and mix. Allow thesolution to stand for at least 10 min.10.5
41、Preparation of Calibration Solutions for Spectropho-tometric MeasurementsTransfer with the help of a pipet 0.0,1.0, 3.0, 5.0, 7.0, and 10.0 mLof the titanium standard SolutionB(7.14.2) to six 100-mL volumetric flasks, add 5 mL of ferricammonium sulfate solution (7.5) and 10 mL of ascorbic acidsoluti
42、on (7.3), and mix. Add 15 mL of dilute hydrochloric acid(1+1) (7.6) and 30 mL of diantipyrylmethane solution (7.4),dilute to volume, and mix. Allow the solution to stand for atleast 10 min.11. Photometry11.1 Adjust the spectrophotometer to the initial setting,using water as the reference solution. W
43、hile maintaining thissetting, take spectrophotometric readings of the blank, stan-dard, and test solutions, using a light band centered atapproximately 385 nm in a 1-cm cell (see Note 1).11.2 Preparation of Calibration Curve Subtract the aver-age absorbance of the 0-mL titanium standard solution fro
44、mthe average absorbance of each standard solution and plot thenet absorbance against milligrams of titanium per 100 mL ofsolution.11.3 Photometric RangeThe recommended concentrationrange is from 0.03 to 0.2 mg in 100 mL using a cell depth of1 cm.NOTE 3Cells having other dimensions may be used, provi
45、ded suitableadjustments can be made in the amount of sample and reagent used.12. Calculation12.1 Subtract the average absorbance of the reagent blanksolution from the average absorbances of each of the testTABLE 1 Grand Means and Precision of Titanium Content of the Test Samples as Determined by the
46、 Method Described Using VariousDecomposition MethodsSampleNo.DecompositionMethodsGrand MeanX,%Repeatabilityr, %PermissibleToleranceP, %Standard DeviationWithin-Laboratoriessr,%Between-LaboratoriessL,%76-3 Acid 3.7944 0.0788 0.1706 0.0285 0.058276-3 Sintering 3.8137 0.0848 0.2765 0.0306 0.097476-3 Fu
47、sion 3.8122 0.0785 0.1995 0.0283 0.069276-16 Acid 0.0399 0.0023 0.0042 0.0008 0.001476-16 Sintering 0.0402 0.0026 0.0051 0.0009 0.001776-16 Fusion 0.0402 0.0015 0.0034 0.0005 0.001276-17 Acid 0.1602 0.0032 0.0102 0.0012 0.003676-17 Sintering 0.1625 0.0049 0.0133 0.0018 0.004676-17 Fusion 0.1608 0.00
48、55 0.0129 0.0020 0.004476-18 Acid 0.1796 0.0049 0.0081 0.0018 0.002776-18 Sintering . . . . .76-18 Fusion 0.1856 0.0090 0.0159 0.0032 0.0053TABLE 2 Regression Equations of the Precisions as Functions of Titanium Content in the Samples for Various Methods ofDecomposition(a) Acid Attack (b) Sintering
49、(c) Fusionr = 0.0202 3 + 0.0035 r = 0.0219 3 + 0.0015 r = 0.0197 3 + 0.0040P = 0.0438 3 + 0.0068 P = 0.0725 3 0.0017 P = 0.0508 3 + 0.0074sr= 0.0072 3 + 0.0016 sr= 0.0079 3 + 0.0005 sr= 0.0071 3 + 0.0014sL= 0.0150 3 + 0.0022 sL= 0.0256 3 0.0008 sL= 0.0176 3 + 0.0025E 878 01 (2005)3solutions. Convert the net absorbance of the test solutions tomilligrams of titanium by means of the calibration curve.Calculate the percentage of titanium as follows:Titanium, % 5 0.1 A/B (1)where:A = titanium found in the aliquot used, mg, andB = test sampl
