ASTM_C_492_-_92_2013.pdf

Designation:C49292(Reapproved 2013)Standard Test Method forHydration of Granular Dead-Burned Refractory Dolomite1This standard is issued under the fixed designation C492;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the amountof hydration of a granular dead-burned refractory dolomitewhen exposed to moist air.1.2 The values stated in inch-pound units are to regarded asthe standard.The values given in parentheses are for informa-tion only.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C92 Test Methods for Sieve Analysis and Water Content ofRefractory MaterialsE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3.Significance and Use3.1 The hydration of dead-burned dolomite grains is animportant aspect of both manufacturing and using such grains.Moisture from any source will cause the grains to partiallydisintegrate,eventually making the dead-burned dolomite unfitfor use.This test method may prove useful for determining,ina relative manner,which grains are more resistant to hydrationthan others.3.2 Data from one laboratory might help in establishinginternal limits for determining whether a particular batch ofgrain is suitable for refractory production.However,this testmethod takes great care to run,and is not recommended as aquality control test.Possibly,a specification might be devel-oped between two parties if sufficient care in establishing thebias between the laboratories is carried out.4.Apparatus4.1 Sieve,ASTM No.40(425-m)(equivalent to a 35-meshTyler Standard Series)conforming to Specification E11,withpan and cover.4.2 Glass Petri Dishes,95 by 20-mm.4.3 Circulating Hot-Air Oven,capable of operating at 220 to230F(104 to 110C).4.4 Steam-Humidity Cabinet,to be maintained at 160 6 2F(71 6 1C)and 85 6 3%humidity.34.5 Scale,having a capacity of 200 g,accurate to 0.02 g.5.Sampling5.1 The sample used shall be quartered or riffled so that it istypical of the material being tested both in screen size andoiling.All material passing the No.40(425-m)sieve shall beremoved from this sample by screening.All screening shall bedone in accordance with Test Methods C92 for dry sieveanalysis.6.Procedure6.1 Place a 100 6 0.1-g portion of the representative sampleretained on the No.40(425-m)sieve sample in a 95 by20-mm Petri dish.Then place this dish in a hot-air oven for12h at 220 to 230F(104 to 110C)to prevent condensation ofwater on the sample when placed in a hot steam-humiditycabinet.6.2 Transfer the Petri dish containing the sample from thehot-air oven to the steam-humidity cabinet,and cover with aglass plate at an angle of 45 to prevent dripping on the sample.The edges of the glass plate shall overhang the Petri dish byabout34in.(19 mm).6.3 Maintain the steam-humidity cabinet at 160 6 2F(716 1C)and 85 6 3%humidity for 24 h.The time to reachthese conditions shall be approximately12h.Then immedi-ately remove the Petri dish from the cabinet and place in a1This test method is under the jurisdiction of ASTM Committee C08 onRefractories and is the direct responsibility of Subcommittee C08.04 on ChemicalBehaviors.Current edition approved April 1,2013.Published August 2013.Originallyapproved in 1962.Last previous edition approved in 2008 as C492 92(2013).DOI:10.1520/C0492-92R13.2For 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.3An apparatus manufactured by the American Instrument Co.,8030 GeorgiaAve.,Silver Spring,MD,or the Electric Hotpack Co.,Philadelphia,PA,has beenfound suitable for this purpose.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 hot-air oven at 220 to 230F(104 to 110C)for12h or until aconstant weight is attained.Then screen the sample on a No.40(425-m)sieve and weigh the material passing the sieve to thenearest 0.1 g.Always run the tests in triplicate.7.Report7.1 Report the hydration of a sample as the average percent-age of material passing the No.40(425-m)sieve after thehydration test.8.Precision and Bias8.1 Interlaboratory Study:8.1.1 An interlaboratory test program between four labora-tories was conducted.Each laboratory tested three dolomiticmaterials.Each of the three dolomitic materials was tested fourtimes.8.1.2 No ruggedness test was run on this test method priorto conducting th