1、Designation: D 717 86 (Reapproved 2008)Standard Test Methods forAnalysis of Magnesium Silicate Pigment1This standard is issued under the fixed designation D 717; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. 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 magnesiumsilicate pigment.1.2 The values stated in SI units are to be regarded as the
3、standard. 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 regu
4、latory 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 718 Test Methods for Analysis of Aluminum SilicatePigmentD 1193 Specificat
5、ion 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 thePigmentE97 Test Method for Directional Reflectance Factor, 45-deg 0-deg, of Opaque Specimens by Broad-Band
6、 FilterReflectometry33. Significance and Use3.1 These test methods may be used to confirm the statedSiO2, CaO, and MgO content of magnesium silicate for qualitycontrol.4. Apparatus4.1 Platinum Crucible.4.2 Electric Furnace, capable of 1200C.5. Purity of Reagents5.1 Reagent grade chemicals shall be u
7、sed 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, where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reage
8、nt 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 1193.SILICON DIOXIDE6. Reagents6.1 Hydrochloric Acid (sp gr 1.19)Concentrated hydro-chloric
9、acid (HCl).6.2 Hydrochloric Acid (1+20)Mix 1 volume of concen-trated hydrochloric acid (HCl, sp gr 1.19) with 20 volumes ofwater.6.3 Hydrofluoric Acid (48 %)Concentrated hydrofluoricacid (HF).6.4 Sodium Carbonate (Na2CO3).6.5 Sulfuric Acid (sp gr 1.84)Concentrated sulfuric acid(H2SO4).7. Procedure7.
10、1 Transfer1gofthesample weighed to 0.1 mg to aplatinum crucible and fuse with5gofNa2CO3until the entirecontents of the crucible are in a molten state. Continue heatingfor 20 min. Keep a close-fitting platinum cover on the crucibleduring the fusion. When the fusion is complete, allow the1These test m
11、ethods 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. Originallyapproved in 1943. Last previou
12、s edition approved in 2003 as D 717 - 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 page onthe ASTM website.3Withdrawn.4R
13、eagent 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., and the United States Pharmacopeia
14、and 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.crucible and contents to cool, and transfer to a 600-mLporcelain casserole containing 200 mL of water (N
15、ote 1). Boiluntil the melt is disintegrated.NOTE 1If, during the cooling period, the crucible is partially im-mersed several times in cold water to chill the outer portions of the melt,the subsequent removal of the melt is facilitated. Do not allow the waterto enter the crucible while the contents a
16、re hot to avoid spattering.7.2 Remove crucible and lid, being careful to scrub andrinse out any adhering particles of the melt. Carefully acidifythe contents of the casserole with concentrated HCl (sp gr1.19); introduce the HCl in small portions, keeping a watchglass over the crucible to avoid loss
17、by spattering. Add 30 mLof HCl in excess and evaporate to dryness on a steam bath; takecare to break up any crusts that form. When the materialappears completely dry, and no odor of HCl can be detected,remove the casserole from the steam bath, and allow to cool.7.3 Wash down the sides of the cassero
18、le with 20 mL of HCl(sp gr 1.19) and then with water. Repeat the evaporation asdescribed in 7.2, then bake for1hinanoven at 105C. Coolthe residue, drench with 25 mL of HCl (sp gr 1.19), add 175mL of water, and warm, while stirring, until all soluble salts aredissolved. Filter off the silica on a clo
19、se-texture paper, washfive times with HCl (1+20), wash five times with hot water, andreserve the filtrate for determination of other oxides (Section9).7.4 Transfer the paper and washed silica to a clean platinumcrucible, ignite, first gently until the filter paper is consumed,and then at 1200C for 2
20、0 min, cool, and weigh. Moisten theresidue with water, add 5 drops of H2SO4(sp gr 1.84), and 15mL of HF. Evaporate to dryness on a steam bath, heat gentlyuntil H2SO4has been expelled, and ignite at 1200C for 5 min.Cool and weigh. The loss in weight represents the SiO2.8. Calculation8.1 Calculate the
21、 percent of silica as follows:SiO2,%5 P/S! 3 100 (1)where:P = SiO2,g,andS = sample used, g.AMMONIUM HYDROXIDE GROUP(Alumina and Iron Oxide)9. Reagents9.1 Ammonium Chloride Solution (2 g/100 mL)Dissolve 2g of ammonium chloride (NH4Cl) in 100 mL of water.9.2 Ammonium Hydroxide (sp gr 0.90)Concentrated
22、 am-monium hydroxide (NH4OH).9.3 Hydrochloric Acid (1+3)Mix 1 volume of concen-trated HCl (sp gr 1.19) with 3 volumes of water.9.4 Methyl Red Indicator SolutionDissolve 0.2 g of me-thyl red in 100 mL of methanol, ethanol, or isopropanol.9.5 Potassium Pyrosulfate(K2S2O7).10. Procedure10.1 If an appre
23、ciable residue remains after the treatmentwith HF in accordance with 7.4, fuse the residue with a smallamount of K2S2O7until it is dissolved. Leach the pyrosulfatemelt out of the crucible with water and combine the solutionwith the filtrate reserved in accordance with 7.3.10.2 Using the methyl red i
24、ndicator solution, neutralize thecombined solutions from the silica determination with NH4OHand add an excess of 2 drops. Bring to a boil adding NH4OH1 drop at a time if necessary to maintain a slight alkalinity.Allow the precipitate to settle (not more than 5 min) and filter.Wash four times with ho
25、t NH4Cl solution.10.3 Set aside the filtrate and transfer the precipitate andfilter paper to the same beaker in which the first precipitationwas effected. Dissolve the precipitate with 40 mL of hot HCl(1+3), dilute the solution to about 100 mL, and reprecipitate thehydroxides as described in 10.2. F
26、ilter and wash the precipitatefour times with hot NH4Cl. Combine the filtrate and washingswith the filtrate set aside and reserve for the determination ofCaO (Section 10).10.4 Place the precipitate in a weighed platinum crucible,heat slowly until the papers are charred, and finally ignite toconstant
27、 weight at 1050 to 1100C with care to preventreduction. Cool and weigh as R2O3(aluminum and iron ox-ides).11. Calculation11.1 Calculate the percent of R2O3as follows:R2O3,%5 P2/S! 3 100 (2)where:P2=R2O3,g,andS = sample used, g.CALCIUM OXIDE12. Reagents12.1 Ammonium Hydroxide (1+1)Mix 1 volume of con
28、-centrated NH4OH (sp gr 0.90) with 1 volume of water.12.2 Ammonium Oxalate Solution(NH4)2C2O4H2O),saturated.12.3 Ammonium Oxalate Solution (1 g/L)Dilute 1.0 g ofammonium oxalate (NH4)2C2O4H2O) in 1 L of water.12.4 Hydrochloric Acid (1+3)See 9.3.12.5 Hydrochloric Acid (1+1)Mix 1 volume of concen-trat
29、ed hydrochloric acid (HCl, sp gr 1.19) with 1 volume ofwater.12.6 Methyl Red Indicator SolutionSee 9.4.13. Procedure13.1 Acidify the combined filtrates obtained in the precipi-tations of the ammonium hydroxide group (Section 10) withHCl and evaporate them to a volume of about 300 mL. Add 5mL of HCl
30、(1+1), a few drops of methyl red indicator solution,and 30 mL of warm ammonium oxalate solution (saturated).Heat the solution to 70 to 80C and add NH4OH (1+1)dropwise while stirring, until the color changes from red toyellow. Allow the solution to stand without further heating for1 h (no longer) wit
31、h occasional stirring during the first 30 min.Filter and wash moderately with cold dilute ammonium oxalatesolution. Reserve the filtrate and washings.13.2 Transfer the precipitate and filter paper to the beaker inwhich the precipitate was effected. Dissolve the oxalate in 40D 717 86 (2008)2mL of hot
32、 HCl (1+3) and macerate the filter paper. Dilute to200 mL with water, add a few drops of methyl red indicatorsolution and 5 mL of ammonium oxalate solution (saturated).Heat the solution nearly to boiling, and precipitate calciumoxalate again by neutralizing the acid solution with NH4OH asdescribed i
33、n 13.1.Allow the solution to stand 1 to 2 h and washas before. Combine the filtrate with that already obtained andreserve for the determination of MgO (Section 16).13.3 Dry the precipitate in a weighed covered platinumcrucible. Char the paper without inflaming, burn the carbon atas low a temperature
34、 as possible, and, finally, heat with thecrucible tightly covered in an electric furnace or over a blastlamp at a temperature of 1100 to 1200C. Cool in a desiccatorand weigh as CaO. Repeat the ignition to a constant weight.14. Calculation14.1 Calculate the percent of CaO as follows:CaO, % 5 P3/S! 3
35、100 (3)where:P3= CaO, g, andS = sample used, g.MAGNESIUM OXIDE15. Reagents15.1 Ammonium Hydroxide (sp gr 0.90)Concentrated am-monium hydroxide (NH4OH).15.2 Ammonium Hydroxide (5+95)Mix 5 volumes ofconcentrated NH4OH (sp gr 0.90) with 95 volumes of water.15.3 Diammonium Phosphate Solution (250 g/L)Di
36、ssolve250 g of diammonium phosphate (NH4)2HPO4in enough waterto yield 1 L of solution.15.4 Hydrochloric Acid (1+3)See 9.3.16. Procedure16.1 Acidify the filtrates reserved in the determination ofCaO (Section 13) with HCl and concentrate to about 400 mL.Add to this solution about 50 mL of (NH4)2HPO4(2
37、50 g/L) andif the solution becomes alkaline, add HCl (1+3) to keep thesolution acidic. Cool the solution by placing the beaker in acold water trough or in a tray of ice water. After cooling addNH4OH drop by drop, while stirring constantly, until thecrystalline magnesium ammonium phosphate begins to
38、form,and then in moderate excess (5 to 10 % of the volume of thesolution), the stirring being continued for several minutes. Setthe solution aside for at least8hinacool atmosphere.16.2 Filter the solution on a close-texture paper and washwith NH4OH (5+95). Unfold the filter paper and, using hotwater
39、, wash the precipitate into the beaker in which theprecipitation was effected. Rinse the filter paper with hot HCl(1+3) and again with hot water; if necessary add more hot HCl(1+3) to dissolve the precipitate. Dilute the solution to about250 mL, add 1 mL of (NH4)2HPO4solution, and then addconcentrat
40、ed NH4OH drop by drop, while stirring constantly,until the precipitate is again formed as described in the NH4OHis in moderate excess. Cool and allow to stand for about 4 h.16.3 Filter the solution on a close-texture paper and washsix times with NH4OH (5+95). Transfer the precipitatewrapped in the m
41、oist paper to a weighed platinum or porcelaincrucible, slowly char the paper without allowing it to ignite andcarefully burn off the carbon over a gradually increasing flamewhich shall never heat the crucible to more than the faintestred. Finally ignite at 1000 to 1100C to constant weight, takingcar
42、e to avoid melting the pyrophosphate.17. Calculation17.1 Calculate the percent of MgO to 0.1 as follows:MgO, % 5 P43 0.3623!/S 3 100 (4)where:P4=Mg2P2O7,g,andS = sample used, g.molecular weight 0.2 MgOmolecular weight Mg2P2O752 3 40.32222.605 0.3623 (5)17.2 Consider the sum of MgO, CaO, and SiO2as c
43、ombinedmagnesium and calcium silicate.LOSS ON IGNITION18. Procedure18.1 Determine the loss on ignition in accordance with TestMethods D 1208.MOISTURE AND OTHER VOLATILE MATTER19. Procedure19.1 Determine the moisture and other volatile matter byTest Methods D 280.COARSE PARTICLES(Total Residue Retain
44、ed on a No. 325 (45-m) Sieve)20. Procedure20.1 Determine the coarse particles in accordance with TestMethods D 718, except that the specimen weight should beadjusted to provide appropriate sensitivity for the residualweight determination. Any difficulty encountered in wetting-out the specimen can be
45、 overcome by prewetting with a 50+50mixture of acetone or alcohol and water.MATTER SOLUBLE IN WATER21. Procedure21.1 Determine the matter soluble in water by Test MethodD 2448 or alternatively by Test Methods D 1208.COLOR22. Standard Pigment22.1 Standard Extender Pigment.22.2 Standard Zinc Oxide.23.
46、 Procedure23.1 Carefully weigh out the proportions 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 requi
47、red.D 717 86 (2008)3Prepare a similar paste 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
48、 so as to present them on aneven plane, and judge the color immediately.24. Dry Brightness24.1 The test sample and reference sample shall be preparedinto suitable smooth, dry, packed surfaces in accordance withaccepted practice and tested for reflectance using the greenfilter in accordance with Test
49、 Method E97.PRECISION25. Precision and Bias25.1 Data are not available to determine the precision andbias of these test methods. There are no plans at present toobtain such information. The methods have been in use forseveral years and are considered acceptable.26. Keywords26.1 calcium oxide in magnesium silicate; magnesium ox-ide in magnesium silicate; magnesium silicate pigment, analy-sis of; silicon dioxide, analysis ofASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentio
