1、Designation: D 718 86 (Reapproved 2008)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:2D 234 Specification for Raw Linseed Oil3D 280 Test Methods for Hygroscopic Moisture (and OtherMatter Volatile Under the Test Conditions) in PigmentsD 717 Test Methods for Analysis of Magnesium SilicatePigmentD 1193 Specificati
5、on for Reagent WaterD 1208 Test Methods for Common Properties of CertainPigmentsD 2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigmentE11 Specification for Wire Cloth and Sieves for TestingPurposes3. Significance and Use3.1 These test
6、 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 400 to 5
7、50nm.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,4where suchspecifications
8、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 D 119
9、3.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 ammonium ch
10、loride (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).7.5 Hydrochloric Acid (sp gr 1.19)Concentrated h
11、ydro-chloric acid (HCl).1These test methods are under the jurisdiction 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 Feb. 1, 2008. Published February 2008. Ori
12、ginallyapproved in 1943. Last previous edition approved in 2003 as D 718 86 (2003).2For 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 standards Document Summary pa
13、ge onthe ASTM website.3Withdrawn.4Reagent 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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K.,
14、 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 Conshohocken, PA 19428-2959, United States.7.6 Hydrochloric Acid (1+3)Mix 1 volume of concen-trated HCl (sp gr 1
15、.19) with 3 volumes of water.7.7 Hydrofluoric Acid (48 %)Concentrated hydrofluoricacid (HF).7.8 Hydrogen Peroxide (H2O2, 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. Pre
16、pare freshweekly.7.10 Iron StandardDissolve 0.1 g of analytical grade ironwire in 10 mL of HCl (1+1) and dilute to 1 L. 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
17、, or isopropanol.7.13 Potassium Dichromate, Standard Solution (0.05 N)Dissolve 2.457 g of potassium dichromate (K2Cr2O7) 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 titrat
18、ion asthe sample to be analyzed.7.14 Phosphoric Acid (H3PO4,85%)Concentrated phos-phoric acid.7.15 Potassium Pyrosulfate (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
19、(SnCl3,2H2O) in 10 mL of concentratedHCl (sp gr 1.19) and dilute to 100 mL with water. Add scrapsof iron-free granulated 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 sulf
20、uric acid (H2SO4, sp gr 1.84) to 1 volume ofdistilled water.7.19 Sulfuric Acid (1+9)Add carefully 1 volume of con-centrated 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, fus
21、ethe residue with a small amount of K2S2O7until it is dissolved.Leach the pyrosulfate melt out of the crucible with water 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
22、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. 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,
23、 boil for 1 or 2 min, and filter. Wash theprecipitate once by decantation and then slightly on the filterwith hot NH4Cl.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
24、asdescribed in 8.2. After filtering, wash the precipitate ten timeswith small portions of hot NH4Cl solution. Transfer 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,
25、takingcare to avoid reduction. Weigh the precipitate asAl2O3+TiO2+Fe2O3.8.4 Fuse the combined oxides from 8.3 with9to10gofK2S2O7in 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 m
26、Lof water and warm to effect solution. Transfer the solution to a250-mL volumetric flask, dilute to volume, and 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 con
27、taining 0.5 to 3 % TiO2,a20-mL aliquot is suitable. Add 5 mL of H2O2(3 %), dilute tovolume with H2SO4(1+9) and 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 re
28、adings to a curveplotted from a set of TiO2standards similarly treated and readon the same instrument.8.6 Determine 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 o
29、f NH4C2H3O2(20 %),and 10 mL of o-phenanthroline (0.1 %). Roll a small piece ofcongo red paper into a ball and 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 s
30、uitable colorimeter usinga filter with transmission limits 485 to 550 nm, or at 510 nmwith a prism or grating 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
31、 follows: Fuse1gofsample with 10 g of K2S2O7in ahigh-silica crucible starting at low temperature and increasingthe 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
32、 heat to disintegrate the cake. Filter and wash free ofchlorides with hot water. Save filtrate. Ignite the insolubleresidue 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 drop
33、s more of H2SO4(1+1) and combine the solution withthe bulk of the iron. Add 5 mL of HCl to the combinedsolutions 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 ro
34、om temperature, wash downthe inside of the beaker with water, and add at one stroke 10mL of cool HgCl2solution (saturated). Stir the solutionvigorously for 1 min, add 5 mL of phosphoric acid (85 %) and3 drops of diphenylamine indicator solution. Titrate with 0.05D 718 86 (2008)2N K2Cr2O7solution to
35、an intense deep-blue end point thatremains unchanged on further addition of K2Cr2O7solution.8.9 Calculate the 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
36、 100P/S! 2 C (2)where:P = weight of combined oxides Al2O3+TiO2+Fe2O3,S = specimen weight, g, andC =Fe2O3+TiO2,%.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 m
37、atter in accor-dance with Test Methods D 280.COARSE PARTICLES(Total Residue Retained on a No. 325 (45-m) Sieve)11. Apparatus11.1 SieveA No. 325 (45-m) 76 mm (3-in.) diameterhigh form sieve conforming to Specification E11, shall beused.11.2 Stirring Apparatus, consisting of:11.2.1 Mixing CupA stainle
38、ss steel cup, about 178 mm (7in.) deep, and slightly tapered from an outside diameter at thetop of about 102 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 elec
39、tric motor turns a vertical shaft at a speedof not less than 10 000 r/min without load. The shaft shall beequipped 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 (11
40、2 in.) above the bottom of the dispersion cup.A common malted milk-type mixer of high quality meets thisspecification.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 mLo
41、f water to which has been added about 2 drops of 0.5 %solution sodium silicate, and stir for about 10 min at 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 t
42、he specimen to the sieve. Spray the sieve surfacegently with a low pressure fan-shaped spray (tap water at 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
43、 Calculation:Percent of coarse particles (3)5increase in weight of sieve/specimen weight!3100!MATTER SOLUBLE 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 Careful
44、ly weigh out the proportion of the standardextender pigment and standard zinc oxide mutually agreedupon, and 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 p
45、aste with the sample using the same weightof pigment, volume of oil, and number of strokes of the glassmuller 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 ju
46、dge the color immediately.PRECISION AND BIAS16. Precision and Bias16.1 Data are not available to determine 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 alu
47、minum oxide in aluminum silicate pigment; alumi-num silicate pigment, analysis of; pigment, aluminum silicateD 718 86 (2008)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are ex
48、pressly 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 subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revi
49、sed, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. 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 standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Bo
