1、Designation: D 718 86 (Reapproved 2003)Standard Test Methods forAnalysis of Aluminum Silicate Pigment1This standard is issued under the fixed designation D 718; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 These test methods cover the analysis of aluminumsilicate pigment.1.2 The values stated in SI units are to be regarded as thest
3、andard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address the safetyconcerns associated with its use. It is the responsibility of theuser of this standard to establish appropriate safety and healthpractices and determine the applicability of regula
4、tory limita-tions prior to use.2. Referenced Documents2.1 ASTM Standards:D 234 Specification for Raw Linseed Oil2D 280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile Under the Test Conditions) in Pigments3D 717 Test Methods for Analysis of Magnesium SilicatePigment2D 1193 Specificat
5、ion for Reagent Water3D 1208 Test Methods for Common Properties of CertainPigments2D 2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigment2E 11 Specification for Wire Cloth and Sieves for TestingPurposes43. Significance and Use3.1 Thes
6、e test methods may be used to confirm the statedaluminum oxide and SiO2content of aluminum silicate forquality control.4. Apparatus4.1 Platinum Crucible.4.2 Electric furnace (or gas burner), capable of 1050 to1100C.4.3 Volumetric flask, 100 and 250 mL.4.4 Colorimeter, with transmission range from 40
7、0 to 550nm.4.5 High Silica Crucible.5. Purity of Reagents5.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society,5where suchspecifica
8、tions are available. Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 Unless otherwise indicated, references to water shall beunderstood to mean Type II of Specification
9、 D 1193.SILICON DIOXIDE6. Procedure6.1 Determine the silicon dioxide content in accordancewith Test Methods D 717.ALUMINUM OXIDE7. Reagents7.1 Ammonium Acetate (20 %)Dissolve 200 g of ammo-nium acetate (NH4C2H3O2) in 1 L of distilled water.7.2 Ammonium Chloride Solution (20 g/L)Dissolve 20 gof ammon
10、ium chloride (NH4Cl) in water and dilute to 1 L.7.3 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).7.4 Diphenylamine Indicator Solution (1 g/100 mL)Dissolve1gofdiphenylamine in 100 mL of concentratedsulfuric acid (H2SO4, sp gr 1.84).1These test methods are under the jurisdic
11、tion of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1943. Last previous edition approved in 1986 as
12、D 718 86 (1999).2Annual Book of ASTM Standards, Vol 06.03.3Annual Book of ASTM Standards, Vol 11.01.4Annual Book of ASTM Standards, Vol 14.02.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted b
13、y 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Con
14、shohocken, PA 19428-2959, United States.7.5 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric acid (HCl).7.6 Hydrochloric Acid (1+3)Mix 1 volume of concen-trated HCl (sp gr 1.19) with 3 volumes of water.7.7 Hydrofluoric Acid (48 %)Concentrated hydrofluoricacid (HF).7.8 Hydrogen Peroxide (H2O2
15、, 3 %, freshly prepared)Mix 1 volume of H2O2(30 %) with 9 volumes of distilledwater.7.9 Hydroxylamine Hydrochloride (10 %)Dissolve 10 gof NH2OH HCl in 100 mL of distilled water. Prepare freshweekly.7.10 Iron StandardDissolve 0.1 g of analytical grade ironwire in 10 mL of HCl (1+1) and dilute to 1 L.
16、 Each millilitrecontains 0.1 mg of Fe.7.11 Mercuric Chloride Solution (HgCl2), saturated.7.12 Methyl Red Indicator SolutionDissolve 0.2 g ofmethyl red in 100 mL of methanol, ethanol, or isopropanol.7.13 Potassium Dichromate, Standard Solution (0.05 N)Dissolve 2.457 g of potassium dichromate (K2Cr2O7
17、) in waterand dilute to 1 L. Standardize against National Bureau ofStandards standard sample No. 27b of Sibley iron ore, usingsuch an amount as to give approximately the same titration asthe sample to be analyzed.7.14 Phosphoric Acid (H3PO4, 85 %)Concentrated phos-phoric acid.7.15 Potassium Pyrosulf
18、ate (K2S2O7).7.16 o-Phenanthroline (0.1 %)Dissolve 1.0 g ofo-phenanthroline in 1 L of hot distilled water.7.17 Stannous Chloride Solution (5 g/100 mL)Dissolve 5g of stannous chloride (SnCl3,2H2O) in 10 mL of concentratedHCl (sp gr 1.19) and dilute to 100 mL with water. Add scrapsof iron-free granula
19、ted tin, and boil until the solution is clear.Keep the solution in a closed dropping bottle containingmetallic tin.7.18 Sulfuric Acid (1+1)Add carefully 1 volume of con-centrated sulfuric acid (H2SO4, sp gr 1.84) to 1 volume ofdistilled water.7.19 Sulfuric Acid (1+9)Add carefully 1 volume of con-cen
20、trated H2SO4(sp gr 1.84) to 9 volumes of distilled water.8. Procedure8.1 If an appreciable residue remains after the treatmentwith HF in accordance with 7.4 of Test Methods D 717, fusethe residue with a small amount of K2S2O7until it is dissolved.Leach the pyrosulfate melt out of the crucible with w
21、ater andcombine the solution with the filtrate reserved in accordancewith 7.3 or Test Methods D 717.8.2 Bring the volume of the combined solution to 250 mL,and, if necessary, add HCl in order to ensure a total of 10 to 15mL of HCl, add a few drops of methyl red indicator solution,and heat to boiling
22、. Add concentrated NH4OH (sp gr 0.90)dropwise until 1 drop changes the color of the solution to adistinct yellow. Reheat the solution containing the precipitatedhydroxides to boiling, boil for 1 or 2 min, and filter. Wash theprecipitate once by decantation and then slightly on the filterwith hot NH4
23、Cl.8.3 Transfer the precipitate and paper to the original beakerin which the precipitation was made. Dissolve the precipitate inhot HCl (1+3), dilute to 100 mL, and precipitate again asdescribed in 8.2. After filtering, wash the precipitate ten timeswith small portions of hot NH4Cl solution. Transfe
24、r theprecipitate to a weighed platinum crucible, heat slowly untilthe paper is charred, and finally ignite to constant weight at1050 to 1100C in an electric furnace or over a burner, takingcare to avoid reduction. Weigh the precipitate as Al2O3+TiO2 +Fe2O3.8.4 Fuse the combined oxides from 8.3 with
25、9 to 10 g ofK2S2O7in a platinum crucible, starting at low temperature andincreasing the heat gradually until the oxides have all dis-solved. Take up the melt with 5 mL of H2SO4(1+1) in 150 mLof water and warm to effect solution. Transfer the solution to a250-mL volumetric flask, dilute to volume, an
26、d mix well.Reserve for TiO2and Fe2O3determinations.8.5 Determine the percent of TiO2as follows: Pipet analiquot containing 0.2 to 3.0 mg of TiO2into a 100-mLvolumetric flask. For samples containing 0.5 to 3 % TiO2,a20-mL aliquot is suitable. Add 5 mL of H2O2(3 %), dilute tovolume with H2SO4(1+9) and
27、 mix well. Obtain the colorimet-ric reading in a suitable colorimeter using a filter withtransmission limits of 400 to 450 nm or at 410 nm with a prismor grating spectrometer. Compare the readings to a curveplotted from a set of TiO2standards similarly treated and readon the same instrument.8.6 Dete
28、rmine the percent of Fe2O3as follows: Pipet a25-mL aliquot into a 100-mL volumetric flask. Add thefollowing in the order given, mixing well after each addition:2mLofNH2OH HCl (10 %), 10 mL of NH4C2H3O2(20 %),and 10 mL of o-phenanthroline (0.1 %). Roll a small piece ofcongo red paper into a ball and
29、introduce into the flask. Addconcentrated NH4OH dropwise until indicator turns red and 1drop in excess. Dilute to volume and let stand for 10 to 20 min.Obtain the colorimetric reading in a suitable colorimeter usinga filter with transmission limits 485 to 550 nm, or at 510 nmwith a prism or grating
30、spectrometer. Compare the readings toa curve plotted from a set of Fe2O3standards similarly treatedand read on the same instrument.8.7 Alternatively the Fe2O3may be determined by titrationas follows: Fuse1gofsample with 10 g of K2S2O7in ahigh-silica crucible starting at low temperature and increasin
31、gthe heat gradually until the crucible glows with a dull red colorand decomposition is judged to be complete. Leach the meltwith 10 mL of concentrated HCl in 100 mL of water and digestat low heat to disintegrate the cake. Filter and wash free ofchlorides with hot water. Save filtrate. Ignite the ins
32、olubleresidue in a platinum crucible. Treat with 5 mL of H2SO4(1+1)and 15 mL of HF (48 %), and heat until fumes of H2SO4appear. Bring the residue into solution with the addition of afew drops more of H2SO4(1+1) and combine the solution withthe bulk of the iron. Add 5 mL of HCl to the combinedsolutio
33、ns and evaporate to 50-mL volume.8.8 To the hot solution add SnCl2solution, dropwise, whilestirring, until the solution is decolorized, and then add 2 to 3drops more. Cool the solution to room temperature, wash downthe inside of the beaker with water, and add at one stroke 10mL of cool HgCl2solution
34、 (saturated). Stir the solutionvigorously for 1 min, add 5 mL of phosphoric acid (85 %) andD 718 86 (2003)23 drops of diphenylamine indicator solution. Titrate with 0.05N K2Cr2O7solution to an intense deep-blue end point thatremains unchanged on further addition of K2Cr2O7solution.8.9 Calculate the
35、percent of Fe2O3as follows:Fe2O3% 5 N 3 V 3 0.0798!/S# 3 100 (1)where:S = sample used, g,V =K2Cr2O7, mL, andN = normality of the K2Cr2O7.8.10 Calculate the percent of Al2O3as follows:Al2O3,%5 100P/S! 2 C (2)where:P = weight of combined oxides Al2O3+TiO2+Fe2O3,S = specimen weight, g, andC =Fe2O3+TiO2
36、,%.LOSS ON IGNITION9. Procedure9.1 Determine loss on ignition in accordance with TestMethods D 1208.MOISTURE AND OTHER VOLATILE MATTER10. Procedure10.1 Determine moisture and other volatile matter in accor-dance with Test Methods D 280.COARSE PARTICLES(Total Residue Retained on a No. 325 (45-m) Siev
37、e)11. Apparatus11.1 SieveA No. 325 (45-m) 76 mm (3-in.) diameterhigh form sieve conforming to Specification E 11, shall beused.11.2 Stirring Apparatus, consisting of:11.2.1 Mixing CupA stainless steel cup, about 178 mm (7in.) deep, and slightly tapered from an outside diameter at thetop of about 102
38、 mm (4 in.) to about 70 mm (234 in. ) at thebottom, such as is characteristic of a usual malted-milk typemixing cup.11.2.2 Mechanically Operated Stirring Device, in which asuitably mounted electric motor turns a vertical shaft at a speedof not less than 10 000 r/min without load. The shaft shall bee
39、quipped with a replaceable stirring button not more than 25mm (1 in.) in diameter, and of such length that the stirringbutton shall operate not less than 19.0 mm (34 in.) nor morethan 38 mm (112 in.) above the bottom of the dispersion cup.A common malted milk-type mixer of high quality meets thisspe
40、cification.12. Procedure12.1 Dry a No. 325 (45-m) sieve in an oven at 105 6 2C,cool, and weigh accurately. Transfer 100 6 0.5 g of thespecimen to the mixing cup containing approximately 250 mLof water to which has been added about 2 drops of 0.5 %solution sodium silicate, and stir for about 10 min a
41、t highspeed. Pour the resulting slurry slowly through the sieve andwash out the mixing cup carefully (a polyethylene squeeze-type wash bottle is very convenient) to ensure completetransfer of the specimen to the sieve. Spray the sieve surfacegently with a low pressure fan-shaped spray (tap water at
42、about5 psig (30 kPa) back pressure) and continue washing until allthe pigment has been washed through and the water passing thesieve is clear. Dry the sieve for1hat105to110C, cool andweigh.12.2 Calculation:Percent of coarse particles (3)5increase in weight of sieve/specimen weight!3100!MATTER SOLUBL
43、E IN WATER13. Procedure13.1 Determine the matter soluble in water by Test MethodD 2448.COLOR14. Standard Pigment14.1 Standard Extender Pigment.14.2 Standard Zinc Oxide.15. Procedure15.1 Carefully weigh out the proportion of the standardextender pigment and standard zinc oxide mutually agreedupon, an
44、d rub up to a fairly stiff paste with a glass muller on aglass plate or stone slab with raw linseed oil conforming toSpecification D 234. Note the volume of the oil required.Prepare a similar paste with the sample using the same weightof pigment, volume of oil, and number of strokes of the glassmull
45、er as used in the preparation of the paste of the standardpigments. Spread the pastes adjacently on a microscope slide,draw a scraper lightly across them to present them on an evenplane, and judge the color immediately.PRECISION AND BIAS16. Precision and Bias16.1 Data are not available to determine
46、the precision andbias of these methods. There are no plans at present to obtainsuch information. The methods have been in use for severalyears and are considered acceptable.17. Keywords17.1 aluminum oxide in aluminum silicate pigment; alumi-num silicate pigment, analysis of; pigment, aluminum silica
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