ASTM_D_537_-_85_1997.pdf

Designation:D 537 85(Reapproved 1997)Standard Specification forSodium Metasilicate1This standard is issued under the fixed designation D 537;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.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 This specification for sodium metasilicate covers mate-rial suitable for various washing,cleaning,and scouringprocesses,with or without soap as conditions demand,andwhere a moderately strong alkaline material is desired.1.2 This material may be hazardous if not properly man-aged.1.3 Precautionary information for the safe use,storage,anddisposal of this material should be preliminarily obtained fromsuppliers and others.1.4 In case of personal accident with this material,applyappropriate first aid;telephone the nearest Poison ControlCenter for assistance,and get medical attention immediately.2.Referenced Documents2.1 ASTM Standards:D 501 Test Methods of Sampling and Chemical Analysis ofAlkaline Detergents23.Sodium Metasilicate3.1 Sodium metasilicate shall be a uniform product in one ofthe following forms as specified by the purchaser:3.1.1 Type I White granular or crystalline material.3.1.2 Type II Granular anhydrous material.4.Ordering Information4.1 Sodium metasilicate shall be purchased by net weightbut in the event of weight shortage it shall be recognized thatsodium metasilicate is subject to a possible gain or loss ofweight due to atmospheric or storage conditions,or both.Therefore,the calculation of net weight shall be based upon aproduct containing 98%of sodium metasilicate calculated asNa2SiO35H2O for Type I or 91.5%of sodium metasilicatecalculated as Na2SiO3for Type II.The net weight of thematerial to be paid for shall be calculated as follows:W 5R 3 T!/98 for Type I(1)W 5R 3 T!/91.5 for Type II(2)where:W 5 net weight of the material to be paid for,R5 net weight of the material as received,T5 total sodium metasilicate calculated as Na2SiO35H2O,andT8 5 total sodium metasilicate calculated as Na2SiO3.4.2 In the event that the calculation under 4.1 results in afigure greater than 100%,the seller waives the right to invoicethe purchaser for any amount in excess of 100%.5.Chemical Composition5.1 Sodium metasilicate,as received,shall conform to therequirements as to chemical composition prescribed in Table 1.6.Sampling and Analysis6.1 The material shall be sampled and analyzed in accor-dance with Test Methods D 501.The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard.Users of this standard are expressly advised that determination of the validity of any suchpatent rights,and the risk of 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 revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards,100 Barr Harbor Drive,West Conshohocken,PA 19428.1This specification is under the jurisdiction of the ASTM Committee D-12 onSoaps and Other Detergents and is the direct responsibility of Subcommittee D12.14on Specifications for Analysis of Inorganic Alkaline Detergents.Current edition approved May 31,1985.Published July 1985.Originallypublished as D 537 39.Last previous edition D 537 57(1980).2Annual Book of ASTM Standards,Vol 15.04.TABLE 1 Chemical RequirementsType IType IIminmaxminmaxSodium metasilicate:Calculated as Na2SiO35H2O,%98.0.Calculated as Na2SiO3,%.91.5.Total alkalinity to methyl orange,as Na2O,%28.530.050.052.0Total silica as SiO2,%27.529.045.0.Matter insoluble in water,%.0.2.0.3Carbonates as CO2,%.1.2.2.01Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.This standard is copyrighted by ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.Individualreprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585(phone),610-832-9555(fax),or serviceastm.org(e-mail);or through the ASTM website(http:/www.astm.org).D 5372