1、Designation: D1394 76 (Reapproved 2014)Standard Test Methods forChemical Analysis of White Titanium Pigments1This standard is issued under the fixed designation D1394; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover procedures
3、 for the chemicalanalysis of white titanium dioxide pigments.1.2 The analytical procedures appear in the following order:SectionsPreparation of Sample 4Qualitative Analysis 5 and 6Moisture 7Total Titanium:Jones Reductor Method 812Aluminum Reduction Method 1317Aluminum Oxide 1822Silica 23291.3 The va
4、lues stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 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 s
5、afety and health practices and determine the applica-bility of regulatory limitations prior to use. A specific hazardstatement is given in Section 19.2. Referenced Documents2.1 ASTM Standards:2D280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile Under the Test Conditions) in Pigments
6、D1193 Specification for Reagent WaterE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated Materials3. Reagents3.1 Purity of ReagentReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reag
7、ents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening the
8、accuracy of the determination.3.2 Unless otherwise indicated, references to water shall beunderstood to mean reagent water conforming to Type IV ofSpecification D1193.4. Preparation of Sample4.1 The sample shall, in all cases, be thoroughly mixed andcomminuted before taking portions for analysis.QUA
9、LITATIVE ANALYSIS5. Reagents5.1 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).5.2 Ammonium Sulfate(NH4)2SO4).5.3 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).5.4 Hydrogen Peroxide (30 %)Concentrated hydrogenperoxide (H2O2).5.5 Hydrogen Sulfide (H2S).5
10、.6 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4).5.7 Sulfuric Acid (1+19)Carefully mix 1 volume ofH2SO4(sp gr 1.84) with 19 volumes of water.5.8 Tartaric Acid.5.9 Tin or Zinc Metal.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materi
11、als, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Dec. 1, 2014. Published December 2014. Originallyapproved in 1956. Last previous edition approved in 2009 as D1394 76 (2009).DOI: 10.1520/D1394-76R14.2For referenced ASTM
12、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, AmericanChemical Soc
13、iety, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD
14、.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Procedure6.1 Place about 0.5 g of the sample in a 250-mL glassbeaker,4and add 20 mL of H2SO4(sp gr 1.84) and 7 to8gof(NH4)2SO4. Mix well and boil for a few minutes. The sampleshould
15、go completely into solution; a residue denotes thepresence of silicon dioxide (SiO2) or siliceous matter. Cool thesolution, dilute with 100 mLof water, heat to boiling, let settle,filter, wash with hot H2SO4(1+19) until free of titanium, andtest the residue for lead, etc.6.2 Test the filtrate for ca
16、lcium, zinc, iron, chromium, etc.,by the regular methods of qualitative analysis.5For the irondetermination add to a portion of the filtrate5goftartaric acid,render slightly ammoniacal, pass in H2S in excess, and digeston a steam bath. No precipitate after 30 min indicates theabsence of iron, nickel
17、, cobalt, lead, copper, etc. A blackprecipitate readily soluble in dilute HCl denotes iron. Fortitanium, test a small portion of the original filtrate with H2O2(a clear yellow-orange color should result) and another portionwith metallic tin or zinc (a pale blue to violet coloration shouldresult). Ne
18、gative results should be shown for sulfide,carbonate, or appreciable water-soluble matter.MOISTURE7. Procedure7.1 Determine moisture and other volatile matter in accor-dance with Test Method A of Test Methods D280.TOTAL TITANIUM BY THE JONES REDUCTORMETHOD8. Scope8.1 This method gives results simila
19、r to those obtained withthe Aluminum Reduction Method, Sections 1317.9. Apparatus9.1 Jones Reductor6having a zinc column at least 450 mmin length, and 19 mm in diameter (Fig. 1 and Fig. 2). Thefiltering pad must be tight enough to hold all the particles ofamalgamated zinc resting on it, and may be m
20、ade of asbestosor, preferably, glass-wool supported by platinum gauze or aperforated porcelain plate. Use the least amount (0.1 to 1.0 %)of mercury that will enable satisfactory control of hydrogenevolution, since heavy amalgamation tends to reduce the rateof reaction. Prepare the amalgam by washing
21、 20-mesh zinc for1 min in enough 1 N HCl to cover it, adding the proper amountof 0.25 M mercuric nitrate or chloride solution, and stirringrapidly for 3 min. Decant the solution and wash the amalgamwith water and store under water to which a few drops of HClhave been added. After using, keep the red
22、uctor filled withwater when not in use, in order that basic salts will not beformed and clog it.10. Reagents10.1 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).10.2 Ammonium Sulfate (NH4)2SO4).10.3 Carbon Steel or IronPure iron or plain carbon steel.10.4 Ferric Sulfate Solut
23、ion (1 mL = 0.02 g Fe)Dissolve20 g of iron or carbon steel in a slight excess of HCl, oxidizewith approximately 12 mL of HNO3, add about 80 mL ofH2SO4, and heat to dense white fumes. Cool, dilute with waterto 1 L, digest on a steam bath until sulfates are dissolved, andfilter if necessary. To oxidiz
24、e any ferrous iron that may bepresent, add 0.1 N KMnO4solution until a faint pink colorpersists for 5 min. Ferric ammonium sulfate (FeNH4(SO4)212H2O) may also be used to prepare this solution (See 15.4).10.5 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).10.6 Iron or Carbon Stee
25、lPure iron or plain carbon steel.10.7 Nitric Acid (sp gr 1.42)Concentrated nitric acid(HNO3).10.8 Sodium OxalateNational Institute of Standards andTechnology standard reference material No. 40 of sodiumoxalate (Na2C2O4).10.9 Potassium Permanganate, Standard Reference Mate-rial (0.1 N, 1 mL = 0.008 g
26、 TiO2)Dissolve 3.16 g of KMnO44Borosilicate glass has been found satisfactory for this purpose.5Treadwell, F. P., and Hall, William T., Qualitative Analysis, John Wiley add approximately 3 mL in excess.20.4 Add 25 mL of EDTA solution. (If the approximatealumina level is known, use the following math
27、ematicalformula for determining the amount of EDTA to add for bestresults: 4 % Al2O3+5=mL of 0.02 M EDTA.) Add,D1394 76 (2014)5dropwise, NH4OH (1+4) until the solution color is just com-pletely changed from red to orange-yellow. Add 10 mL ofbuffer solution and 10 mL of (NH4)2 HPO4solution, boil for5
28、 min, and cool quickly to room temperature in running water.Add 3 drops of xylenol orange indicator solution. If thesolution is purple, yellow-brown, or pink, bring the pH to5.35.7 with acetic acid. If the pH is correct, a pink colorindicates insufficient EDTA; repeat with a new aliquot, startingwit
29、h 20.3 and using 50 mL of EDTA solution in 20.4.20.5 Titrate with ZnSO4solution to a yellow-brown or pinkend point. This titration should be performed quickly near theend point by rapidly adding 0.2-mL increments until the firstcolor change occurs. This color will fade in 5 or 10 s, but is thetrue e
30、nd point. This step is critical, and failure to observe thefirst color change will result in an incorrect value. The fadingend point does not occur in the second titration. This firsttitration must be greater than 8 mL of ZnSO4solution. Formost accurate work this first titration should require 10 to
31、 15mL of ZnSO4solution.20.6 Add2gofNaF,boil for 2 to 5 min, and cool in runningwater. Titrate the EDTA, released from its aluminum complexby the fluoride, with ZnSO4solution to the same end point asin 20.5.21. Calculation21.1 Calculate the aluminum oxide content of the pigmentsample as follows:A 5 Z
32、 3 T!/2 3 S! (1)where:A = percent Al2O3,Z = ZnSO4solution consumed in the second titration, mL,T =Al2O3per millilitre of ZnSO4solution, g, andS = specimen used, g.22. Precision22.1 Based on interlaboratory studies the following criteriashould be used for judging the acceptability of results at the95
33、 % confidence level:22.1.1 RepeatabilityTwo results obtained by the sameoperator on the same sample should be considered suspect ifthey differ by more than 0.22 % relative.22.1.2 ReproducibilityTwo results, each the mean of du-plicates obtained by operators in different laboratories shouldbe conside
34、red suspect if they differ by more than 0.62 %relative.SILICA23. Scope23.1 This method covers the determination of silica intitanium dioxide (TiO2) pigments.24. Summary of Method24.1 The fusion of TiO2pigment with sodium bisulfateleaves only the silica insoluble when the melt is dissolved insulfuric
35、 acid. To assure no loss of the silica the sulfuric acid istaken to fuming to dehydrate the silica. The silica content isdetermined by volatilizing the silica in the weighed filtrationresidue with hydrofluoric acid.25. Apparatus25.1 Erlenmeyer Flask, 250-mL, high silica.25.2 Filter Paper, very fine,
36、 ashless, acid washed.25.3 Platinum Crucible and Cover.25.4 Oven, controlled at 120C.25.5 Muffle Furnace, controlled at 1000 6 25C.26. Reagents26.1 Hydrofluoric Acid (sp gr 1.15)Concentrated hydro-fluoric acid (HF).26.2 Sodium Bisulfate(NaHSO4H2O).26.3 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric
37、 acid(H2SO4).26.4 Sulfuric Acid (1+1)To 1 volume of water add slowlywith stirring 1 volume of concentrated H2SO4.26.5 Sulfuric Acid (1+9)To 9 volumes of water addslowly with stirring 1 volume of concentrated H2SO4.27. Procedure27.1 Transfer1gofpigment weighed to 0.1 mg to a250-mL high silica Erlenme
38、yer flask containing 10 g ofNaHSO4H2O. If an SiO2content in excess of 5 % is expecteda 0.5-g specimen of pigment may be used to facilitate completefusion with 10 g of NaHSO4H2O.27.2 Heat over a Meker burner, frequently swirling the flaskuntil decomposition and fusion is complete and clear (exceptfor
39、 SiO2). Be careful of overheating at start and of spatteringof the fusion.27.3 Allow to cool and to the cold melt, add 25 mL ofH2SO4(1+1), and heat very carefully and very slowly until thefusion is dissolved. Carefully evaporate to fumes of H2SO4.27.4 Cool and carefully add 150 mL of water. Pour ver
40、ysmall amounts of water down the sides of the flask withfrequent swirling of the contents to avoid overheating andspattering. Let cool and filter through fine ashless filter paper,using a 60 gravity funnel.27.5 Wash out all silica from the flask onto the filter paperwith H2SO4(1+9). Police the flask
41、 carefully.27.6 Place the filter paper in a platinum crucible and dry ina 120C oven. Heat the partly covered crucible over a bunsenburner. Avoid flaming the filter paper by heating first the coverfrom above and then the crucible from below. When the filterpaper is consumed, heat at 1000C for 30 min
42、in a mufflefurnace. Cool in a desiccator and weigh the crucible.27.7 Add 2 drops of H2SO4(1+1) and 5 mL of HF (sp gr1.15). Carefully evaporate to dryness, first on a low heat hotplate to remove the HF and then over a bunsen burner toremove the H2SO4. Avoid spattering, especially after removalof the
43、HF.27.8 Ignite at 1000C for 10 min. Cool in a desiccator andweigh the crucible again. The difference in weight is silica.D1394 76 (2014)628. Calculation28.1 Calculate the silica content as follows:SiO2,%5 W2/S3! 3100where:W2= SiO2found, g, andS3= specimen used, g.29. Precision29.1 On the basis of an
44、 interlaboratory test of this testmethod in which six laboratories tested, in duplicate, fivesamples of titanium dioxide ranging in silica content from 1.5to 8.2 %, within-laboratory standard deviation was found to be1.79 % and between-laboratories standard deviation was foundto be 3.44 %. Based on
45、this, the following criteria should beused for judging the precision of results at the 95 % confidencelevel:29.1.1 RepeatabilityTwo results obtained by the sameoperator should be considered suspect if they differ by morethan 5.1 % relative.29.1.2 ReproducibilityTwo results, each the mean ofduplicate
46、s, obtained by operators in different laboratoriesshould be considered suspect if they differ by more than 9.7 %relative.30. Keywords30.1 aluminum oxide; aluminum reduction; chemical analy-sis; Jones Reductor; titanium pigmentASTM International takes no position respecting the validity of any patent
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