1、Designation:D71786(Reapproved 2014)Standard Test Methods forAnalysis of Magnesium Silicate Pigment1This standard is issued under the fixed designation D717;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A n
2、umber in parentheses indicates the year of last reapproval.Asuperscript epsilon()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 thestandard.The v
3、alues 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 regulatory limita-ti
4、ons prior to use.2.Referenced Documents2.1 ASTM Standards:2D234 Specification for Raw Linseed Oil(Withdrawn 2007)3D280 Test Methods for Hygroscopic Moisture(and OtherMatter Volatile Under the Test Conditions)in PigmentsD718 Test Methods for Analysis of Aluminum SilicatePigmentD1193 Specification for
5、 Reagent WaterD1208 Test Methods for Common Properties of CertainPigmentsD2448 Test Method for Water-Soluble Salts in Pigments byMeasuring the Specific Resistance of the Leachate of thePigmentE97 Method of Test for Directional Reflectance Factor,45-Deg 0-Deg,of Opaque Specimens by Broad-BandFilter R
6、eflectometry(Withdrawn 1991)33.Significance and Use3.1 These test methods may be used to confirm the statedSiO2,CaO,and MgO content of magnesium silicate for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
7、 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,where suchspecifications are available.4Other grades may be used,pro-vided it is first ascertained that the reagen
8、t 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 D1193.SILICON DIOXIDE6.Reagents6.1 Hydrochloric Acid(sp gr 1.19)Concentrated hydro-chloric acid(
9、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 1.84Concentrated sulfuric acid(H2SO4).7.Procedure7.1 Transfer 1 g of
10、 the sample weighed to 0.1 mg to aplatinum crucible and fuse with 5 g of Na2CO3until the entirecontents of the crucible are in a molten state.Continue heatingfor 20 min.Keep a close-fitting platinum cover on the crucible1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and
11、 Related Coatings,Materials,and Applications and are the directresponsibility of Subcommittee D01.31 on Pigment Specifications.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1943.Last previous edition approved in 2008 as D717 86(2008).DOI:10.1520/D0717-86R14.2For r
12、eferenced 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.3The last approved version of this historical standard is referenced onw
13、ww.astm.org.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.,and the United States Pharmacop
14、eiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 during the fusion.When the fusion is complete,allow thecrucible and contents to cool,and transfer to a 600-mLpo
15、rcelain casserole containing 200 mL of water(Note 1).Boiluntil the melt is disintegrated.NOTE1If,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 watert
16、o enter the crucible while the contents are 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 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,a
