ASTM_D_5341_-_D_5341M_-_14.pdf

Designation:D5341/D5341M14Standard Test Method forMeasuring Coke Reactivity Index(CRI)and Coke StrengthAfter Reaction(CSR)1This standard is issued under the fixed designation D5341/D5341M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method,patterned after the Nippon Steel testprocedure,describes the equipment and techniques used fordetermining lump coke reactivity in carbon dioxide(CO2)gasat elevated temperatures and its strength after reaction in CO2gas by tumbling in a cylindrical chamber referred to as anI-tester.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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:2D346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisE11 Specification for Woven Wire Test Sieve Cloth and TestSievesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 British Carbonization Research Association Report:Carbonization Research Report 91,“The Evaluation of theNippon Steel Corporation Reactivity and Post-Reaction-Strength Test for Coke.”33.Summary of Test Method3.1 A sample of dried coke of designated origin and size isreacted with CO2gas in a retort at a specified elevatedtemperature for a specified length of time.Two indices,cokereactivity index(CRI)and coke strength after reaction(CSR),are determined using the reacted coke residue.The weight lossafter reaction determines the CRI.The weight retained aftersieving the tumbled reacted coke in a designated number ofrevolutions over a designated turning rate determines the CSR.4.Significance and Use4.1 When coke lumps descend in the blast furnace,they aresubjected to reaction with countercurrent CO2and to abrasionas they rub together and against the walls of the furnace.Theseconcurrent processes physically weaken and chemically reactwith the coke lumps,producing an excess of fines that candecrease burden permeability and result in increased coke ratesand lost hot metal production.This test method is designed tomeasure indirectly this behavior of coke in the blast furnace.5.Apparatus5.1 Electric Furnace(Fig.1),capable of housing the reac-tion vessel assembly containing the coke sample and providinga uniform temperature of 1100 6 5C in the assembly.Furnacedimensions do not impact the test results and may vary from240 to 1035 mm 912to 4034in.in length and 76.2 to88.9 mm 3 to 312in.in outside diameter.However,it ispreferable that the furnace have independently controlledheating in three zones to achieve uniformity of heating in theretort and that this control be achieved with a programmablecontroller.5.2 Reaction Vessel(Fig.1),constructed of a heat-resistantsteel or nickel alloy to the dimensions required to fit snuglyinside the electric furnace selected for use(Note 1).The coketo be tested sits on a porous plate in the reaction vessel.Belowthis porous plate,a gas preheater,such as a bed of ceramicAl2O3balls sitting on a second perforated plate,diffuse the1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct responsibility of Subcommittee D05.15 on MetallurgicalProperties of Coal and Coke.Current edition approved Sept.1,2014.Published September 2014.Originallyapproved in 1993.Last previous edition approved in 2010 as D5341 99(2010)1.DOI:10.1520/D5341_D5341M-14.2For 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.3Available from British Carbonization Research Association,Chesterfield,Derbyshire,England.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 nitrogen(N2)and carbon dioxide introduced into the vessel upthrough the coke bed during the course of the test.The gasenters through inlets and exits through outlets varying from6 to 15 mm 14to58in.in inside diameter and positioned atthe top and bottom of the reaction vessel.During the test,it isimportant that no backpressure be detected when gas enters orexits through these inlets or outlets.The reaction vessel ispositioned such that the coke sample