1、Designation: D 5341 99 (Reapproved 2004)Standard Test Method forMeasuring Coke Reactivity Index (CRI) and Coke StrengthAfter Reaction (CSR)1This standard is issued under the fixed designation D 5341; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase 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 test method, patterned after the Nippon Steel testprocedure, describes the equipmen
3、t 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 SI units are to be regarded as thestandard. The values given
4、 in parentheses are for informationonly.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
5、limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 346 Practice for Collection and Preparation of CokeSamples for Laboratory AnalysisE 11 Specification for Wire Cloth and Sieves for TestingPurposesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of
6、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 C
7、O2gas 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 tu
8、mbled 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 fur
9、nace. 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
10、 blast furnace.5. Apparatus5.1 Electric Furnace (Fig. 1), capable of housing thereaction vessel assembly containing the coke sample andproviding a uniform temperature of 1100 6 5C in theassembly. Furnace dimensions do not impact the test resultsand may vary from 240 to 1035 mm in length and 76.2 to
11、88.9mm in outside diameter. However, it is preferable that thefurnace have independently controlled heating in three zones toachieve uniformity of heating in the retort and that this controlbe achieved with a programmable controller.5.2 Reaction Vessel (Fig. 1), constructed of a heat-resistantsteel
12、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
13、 thenitrogen (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 from 6to 15 mm in inside diameter and positioned at the top andbottom of the reaction vessel. During the test, it is im
14、portantthat no backpressure be detected when gas enters or exitsthrough these inlets or outlets. The reaction vessel is positionedsuch that the coke sample contained in the vessel on top of the1This test method is under the jurisdiction of ASTM Committee D05 on Coaland Coke and is the direct respons
15、ibility of Subcommittee D05.15 on MetalurgicalProperties of Coal and Coke.Current edition approved April 1, 2004. Published May 2004. Originallyapproved in 1993. Last previous edition approved in 1993 as D 5341 93a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
16、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.1Copyright ASTM International, 100 Barr Harbor Drive,
17、 PO Box C700, West Conshohocken, PA 19428-2959, United States.ceramic Al2O3balls is in the center of the controlled tempera-ture zone in the furnace.NOTE 1Inconel 601 is recommended over stainless steel. Inconel 601does not leave scale, that, if not properly removed, can alter a coke sampleweight af
18、ter the test.5.3 FlowmetersRotometers or, preferably, mass flowme-ters shall be used to monitor the amount of N2and CO2gasesused in the test. The accuracy of measuring gas flowratesshould be 61 % of full scale since varying gas flow can causevariability in the test results. Gas pressures through the
19、flowmeters should be maintained at the manufacturers cali-bration specification.5.4 Thermocouple (Fig. 1), of the K, S, or R type normal-ized at 20 to 21C and enclosed in a heat-resistant steel ornickel alloy or ceramic protection tube placed in the center ofthe coke sample in the reaction vessel. A
20、 centering pipe or tubealso made of heat-resistant material is used to guide thethermocouple into its proper location in the coke bed.5.5 Sieves, used for sieving the coke during its preparationfor reactivity testing and after tumbling for strength afterreaction testing. Square mesh sieves having 22
21、.4-, 19.0-, and9.5-mm actual openings between the wires are to be used.Standard test sieves that conform to Specification E 11 shouldalways be used.5.6 Balance, capable of weighing up to 25 kg and sensitiveto 0.1 g (0.000 22 lbs).5.7 Coke Strength After Reaction Tumbler (Fig. 2), consist-ing of a cy
22、lindrical chamber with an internal length of 700 610 mm and an internal diameter 130 6 5 mm, with end caps of10-mm thickness or more (Note 2). This cylindrical chamber isattached to its longitudinal center to an electric motor fittedwith a direct drive fixed gearbox, a drive belt, or, preferably, ah
23、ydraulic drive set for a revolving rate of 20 6 1 r/min (Note3). A revolution counter is fitted so that the power is cut offwhen the cylinder has revolved 600 times in 30 min.NOTE 2Mild carbon steel should be selected to fabricate this tumblerapparatus.NOTE 3Most Japanese publications refer to this
24、as an I600/10test.6. Sampling6.1 The gross sample of coke shall be collected in accor-dance with Test Method D 346.6.2 For the standard procedure, the quantity must be not lessthan 57 kg (125 lbs).7. Preparation of Sample7.1 Sieve the gross sample at 25.0 mm (1 in.) and discardthe undersize.7.2 With
25、 suitable crushing equipment, preferably a jaw orroll crusher, reduce the size of all of the remaining plus 25.0mm (1 in.) to pass a 22.4-mm (78-in.) sieve opening.7.3 Sieve the crushed sample using a 22.4-mm (78-in.) sieveplaced on top of a 19.0-mm (34-in.) sieve. Discard the minus19.0-mm (34-in.)
26、coke, and retain the 22.4- by 19.0-mm (78-by34-in.) fraction for testing.7.4 The size reduction of the plus 25.0 mm (1 in.) should beaccomplished in stages by recrushing any plus 22.4-mm(78-in.) coke remaining after each subsequent double sievingstep until there is no oversize retained on the 22.4-m
27、m (78-in.)sieve. The opening to the crusher should be set such that thegross sample yields at least 10 % of 19.0- by 22.4-mm (34-by78-in.) test coke (Note 4).NOTE 4The size of the sample required for most coke tests dependson collecting sufficient received material to have sufficient natural samplef
28、or testing, that is, stability 75.0 by 50.0 mm (3 by 2 in.). For the CSRtests, most companies crush as-received coke to yield a 19.0- by 22.0-mmproduct. Therefore, 57 kg (125 lbs) of gross sample is not necessarilyrequired. In fact, Nippon Steel Corporation, the originator of the test,believes 10-kg
29、 (22-lbs) sublots of the gross sample is representative of thegross sample collected and is sufficient, with suitable crushing and sievingequipment, to yield enough 19- by 22-mm coke to provide repeatableresults.44Nishi, T., et al, Journal of the Fuel Society of Japan, Vol 61, No 668, 1982, pp1066-1
30、073.FIG. 1 Example of Reactivity Test Apparatus (Dimensions in mm)FIG. 2 Example of I-Type Coke Tumbler (Dimensions in mm)D 5341 99 (2004)27.5 Using a riffle splitter, subdivide the 19.0- by 22.4-mm(34-by78-in.) coke into three test samples, each weighingapproximately 250 g (0.55 lbs).7.6 Dry the te
31、st coke samples to less than 1 % moisture at150C for 2 h.8. Procedure8.1 From each test coke sample prepared in accordance withSection 7, randomly hand pick and accurately weigh to thenearest 0.1 g (0.0002 lb), a 200- 6 2.0-g sample for testing.Record the number of pieces selected from each test sam
32、ple.8.2 Before the reaction vessel is put into the electric furnace,place the weighed sample in the reaction vessel in a manner asto ensure that the thermocouple sits vertically in the center ofthe coke bed with its tip 50 mm from the bottom of the cokebed. A centering guide normally fastened to the
33、 center of the lidis used to ensure this positioning of the thermocouple tip.NOTE 5Variations in coke density may result in different total cokebed heights in the reaction vessel. Therefore, in situations where 50 mmis not the center of the coke bed, adjust the thermocouple tip accordingly.8.3 Purge
34、 the reaction vessel for 5 min at 5 to 10 L/min ofN2before loading the vessel into the furnace. Check for leaksin the assembly during this purge time.8.4 Preheat the furnace to a temperature that will allow thesample, when the sample is loaded into the furnace, to reach1100 6 5C in 30 min.8.5 Place
35、the reaction vessel into the furnace and heat thesample to 1100C in the atmosphere of N2gas. Once thesample temperature of 1100 6 5C is reached, soak the samplefor 10 min in N2gas for a total heat up time of 40 min. Thenheat the samples for 120 min in an atmosphere of CO2gas,with a flow rate of 5.0
36、L/min 6 1.0 % (Note 6). Maintain thecoke bed temperatures at 1100C 6 5C during the test. (Fig.3)8.6 After exactly 120-min exposure to CO2gas, switch backto the N2purge gas at 5 to 10 L/min for 5 min to purge thereactor vessel of CO2. Subsequently, remove the reactionvessel from the furnace, and allo
37、w the sample temperature tocool to 100C.8.7 After cooling, remove the coke sample from the reactionvessel and weigh the coke to the nearest 0.1 g (0.0002 lbs).8.8 Transfer the reacted coke to the strength after reactiontester and tumble for 600 revolutions in 30 min at 20 6 1r/min.8.9 After the 600
38、revolutions, remove all coke from thedrum. Sieve the coke using a 9.5-mm (38-in.) sieve. Weigh thecoke remaining on the 9.5-mm (38-in.) sieve for calculation ofCSR. Weigh the coke passing the 9.5-mm (38-in.) sieve forchecking material losses during tumbling.NOTE 6Since carbon monoxide (CO) is genera
39、ted during the cokereactivity test, the test apparatus should be placed in an area with properventilation. In addition, a CO monitoring device should be used to detectany unsafe buildup of CO gas.9. Number of Tests9.1 Reactivity and strength after reaction tests should bedetermined in duplicate for
40、each coke sample.9.2 If the difference between the weights of coke remainingafter reaction with CO2gas or after tumbling and sieving on the9.5-mm (38-in.) sieve exceed 10 g (0.022 lbs), conduct oneadditional test and report the mean value of all three tests.10. Calculation10.1 For each test, calcula
41、te, to the nearest 0.1 %, thepercentage of coke remaining after reaction in CO2gas and thatremaining after tumbling on the 9.5-mm (38-in.) sieve. Reportthe average of these values for the two or more tests as the CRIand CSR values, respectively.10.1.1 Calculations are made as follows:CRI 5A 2 BA3 10
42、0 (1)CSR 5CB3 100 (2)where:A = original test sample weight before reaction,B = sample weight after reaction in CO2, andC = sample weight of +9.5-mm (38-in.) material after tum-bling.11. Precision and Bias11.1 PrecisionThe relative precision of this test method,characterized by repeatability (Sr, r)
43、and reproducibility (SR, R)has been determined for the following materials to be:CRIMaterial Average SrSRrRSample 2 20.47 0.54 2.23 1.51 6.26Sample 5 21.17 1.53 2.07 4.30 5.78Sample 6 29.53 0.90 2.00 2.53 5.59Sample 3 29.84 1.28 2.29 3.58 6.41Sample 1 32.98 0.52 2.84 1.45 7.95Sample 4 53.00 0.84 3.4
44、6 2.36 9.70CSRMaterial Average SrSRrRSample 4 26.94 1.21 4.46 3.36 12.49Sample 3 30.73 3.19 3.34 8.94 9.34Sample 1 52.68 0.79 2.23 2.22 6.25Sample 6 55.89 1.82 2.55 5.08 7.13Sample 2 63.84 2.36 3.17 6.62 8.87Sample 5 65.96 1.15 1.75 3.22 4.90FIG. 3 CSR Test ProcedureD 5341 99 (2004)3The relative pre
45、cision of this test method for the determina-tion of CRI and CSR of coke covers the range of 20 to 50 forCRI and 27 to 66 for CSR.11.1.1 RepeatabilityThe difference in absolute value be-tween two results of separate and consecutive test determina-tions, carried out on the same sample in the same lab
46、oratory bythe same operator using the same apparatus, may be expectedto occur with a probability of approximately 0.95 (95 %confidence level).The repeatability limit for this method is (see Note 7):CRI 2.8CSR 5.411.1.2 ReproducibilityThe difference in absolute value ofreplicate determinations, carri
47、ed out in different laboratoriesusing samples taken at random from a single sample preparedfrom the same bulk sample after the last stage of reduction,may be expected to occur with a probability of approximately0.95 (95 %) confidence level).The reproducibility limit for this method is (Note 7):CRI R
48、 = 3.21 + 0.12 xCSR R = 14.4 0.13 xwhere x is the average of two single between-laboratoryresults.NOTE 7An interlaboratory study, designed consistent with PracticeE 691, was conducted in 1997. Seven laboratories participated. The detailsof the study and supporting data are given in ASTM Research Rep
49、ortD051022 filed at ASTM Headquarters.11.2 BiasCertified standard reference materials are notavailable for the determination of bias by this test method.12. Keywords12.1 coke; coke reactivity index; coke strength afterreactionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own
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