1、Designation: D5341/D5341M 17D5341/D5341M 17aStandard 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
2、, 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 test procedure, describes th
3、e equipment and techniques used fordetermining lump coke reactivity in carbon dioxide (CO2) gas at elevated temperatures and its strength after reaction in CO2 gasby tumbling in a cylindrical chamber referred to as an I-tester.1.2 The values stated in either SI units or inch-pound units are to be re
4、garded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the
5、safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed
6、 in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.
7、1 ASTM Standards:2D346 Practice for Collection and Preparation of Coke Samples for Laboratory AnalysisE11 Specification for Woven Wire Test Sieve Cloth and Test SievesE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 British Carbonization Research A
8、ssociation Report:Carbonization Research Report 91, “The Evaluation of the Nippon Steel Corporation Reactivity and Post-Reaction-StrengthTest for Coke.”33. Summary of Test Method3.1 A sample of dried coke of designated origin and size is reacted with CO2 gas in a retort at a specified elevated tempe
9、raturefor a specified length of time. Two indices, coke reactivity index (CRI) and coke strength after reaction (CSR), are determinedusing the reacted coke residue.The mass or weight loss after reaction determines the CRI.The mass or weight retained after sievingthe tumbled reacted coke in a designa
10、ted number of revolutions over a designated turning rate determines the CSR.4. Significance and Use4.1 When coke lumps descend in the blast furnace, they are subjected to reaction with countercurrent CO2 and to abrasion asthey rub together and against the walls of the furnace. These concurrent proce
11、sses physically weaken and chemically react withthe coke lumps, producing an excess of fines that can decrease burden permeability and result in increased coke rates and lost hotmetal production. This test method is designed to measure indirectly this behavior of coke in the blast furnace.1 This tes
12、t method is under the jurisdiction ofASTM Committee D05 on Coal and Coke and is the direct responsibility of Subcommittee D05.15 on Metallurgical Propertiesof Coal and Coke.Current edition approved Aug. 1, 2017Nov. 1, 2017. Published September 2017November 2017. Originally approved in 1993. Last pre
13、vious edition approved in 20142017as D5341 14.D5341 17. DOI: 10.1520/D5341_D5341M-17.10.1520/D5341_D5341M-17A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the sta
14、ndards Document Summary page on the ASTM website.3 Available from British Carbonization Research Association, Chesterfield, Derbyshire, England.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previ
15、ous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM Int
16、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Reagents5.1 Nitrogen, with purity greater than 99.9 % by volume, dry and with total oxygen and carbon dioxide concentrations of lessthan 100 mg/kg.5.2 Carbon dioxide, with purity of greater than 99.5 %
17、 by volume, dry with an oxygen concentration less than 100 mg/kg.6. Apparatus6.1 Electric Furnace (Fig. 1), capable of housing the reaction vessel assembly containing the coke sample and providing auniform temperature of 1100 C 6 5 C in the assembly. The position of the coke sample contained in the
18、vessel assembly whenhoused in the furnace shall be in the center of the controlled temperature zone. It is preferable that the furnace have independentlycontrolled heating in three zones to achieve uniformity of heating in the retort and that this control be achieved with aprogrammable controller.6.
19、2 Reaction Vessel (Fig. 1), constructed of a heat-resistant steel or nickel alloy (see Note 1) with an internal diameter of 78 mm6 1 mm 3.07 in. 6 0.039 in. and designed to fit snugly inside the electric furnace selected for use. The coke to be tested sitson a perforated plate in the reaction vessel
20、. Below this perforated plate, a gas preheater, such as a bed of ceramicAl2O3 balls sittingon a second perforated plate, is used to diffuse the nitrogen (N2) and carbon dioxide (CO2) introduced into the vessel up throughthe coke bed during the course of the test. The gas enters through inlets positi
21、oned at the bottom of the reaction vessel and exitsthrough outlets at the top of the reaction vessel varying from 6 mm to 15 mm 14 in. to 58 in. in inside diameter. During the test,it is important that no backpressure be detected when gas enters or exits through these inlets or outlets. The reaction
22、 vessel ispositioned such that the coke sample contained in the vessel on top of the ceramic Al2O3 balls is in the center of the controlledtemperature zone in the furnace. The reaction vessel shall be inspected prior to each use for wear, cracks, or deterioration. Cleanand remove scale that could co
23、ntaminate the test sample if present. The vessel should also be checked for leaks prior to initial useand at specified intervals. See subsection 9.3.NOTE 1Inconel 601 is recommended over stainless steel. Inconel 601 does not leave scale, that, if not properly removed, can alter a coke samplemass or
24、weight after the test.6.3 FlowmetersRotometers or, preferably, mass flowmeters shall be used to monitor the amount of N2 and CO2 gases usedin the test. The accuracy of measuring gas flowrates should be 61 % of full scale since varying gas flow can cause variability inthe test results. Gas pressures
25、through the flowmeters should be maintained at the manufacturers calibration specification.Flowmeters shall be calibrated for the gas being used or the flow rate shall be corrected to account for the difference in the densityof the gas used for calibration.6.4 Thermocouple (Fig. 1), of the K, S, or
26、R type normalized at 20 C to 21C and enclosed in a heat-resistant steel or nickelalloy or ceramic protection tube placed in the center of the coke sample in the reaction vessel. A centering pipe or tube also madeof heat-resistant material is used to guide the thermocouple into its proper location in
27、 the coke bed.6.5 Sieves, used for sieving the coke during its preparation for reactivity testing and after tumbling for strength after reactiontesting. Square mesh sieves having 22.4 mm 78 in., 19.0 mm 34 in., and 9.5 mm 38 in. actual openings between the wires areto be used. Standard test sieves t
28、hat conform to Specification E11 should always be used.FIG. 1 Example of Reactivity Test Apparatus (Dimensions in mm)D5341/D5341M 17a26.6 Balance, capable of weighing up to 25 kg 55.1 lb and sensitive to 0.1 g 0.000 22 lb.6.7 Coke Strength After Reaction Tumbler (Fig. 2), consisting of a cylindrical
29、 chamber with an internal length of 700 mm 610 mm 27 58 in. 6 38 in. and an internal diameter 130 mm 6 5 mm 5 18 in. 6 12 in., with end caps of 10 mm thickness ormore (Note 2). This cylindrical chamber is attached to its longitudinal center to an electric motor fitted with a direct drive fixedgearbo
30、x, a drive belt, or, preferably, a hydraulic drive set for a revolving rate of 20 r/min 6 1 r/min (Note 3).Arevolution counteris fitted so that the power is cut off when the cylinder has revolved 600 times in 30 min.NOTE 2Mild carbon steel should be selected to fabricate this tumbler apparatus.NOTE
31、3Most Japanese publications refer to this as an I600/10 test.7. Sampling7.1 The gross sample of coke shall be collected in accordance with Test Method D346.7.2 For the standard procedure, the quantity must be not less than 57 kg 125 lb.8. Preparation of Sample8.1 Sieve the gross sample at 25.0 mm 1
32、in. and discard the undersize.8.2 With suitable crushing equipment, preferably a jaw or roll crusher, reduce the size of all of the remaining plus 25.0 mm 1in. to pass a 22.4 mm 78 in. sieve opening.8.3 Sieve the crushed sample using a 22.4 mm 78 in. sieve placed on top of a 19.0 mm 34 in. sieve. Di
33、scard the minus 19.0mm 34 in. coke, and retain the 22.4 mm by 19.0 mm 78 in. by 34 in. fraction for testing.8.4 The size reduction of the plus 25.0 mm 1 in. should be accomplished in stages by recrushing any plus 22.4 mm 78 in.coke remaining after each subsequent double sieving step until there is n
34、o oversize retained on the 22.4 mm 78 in. sieve. Theopening to the crusher should be set such that the gross sample yields at least 10 % of 19.0 mm by 22.4 mm 34 in. by 78 in. testcoke (Note 4).NOTE 4The size of the sample required for most coke tests depends on collecting sufficient received materi
35、al to have sufficient natural sample fortesting, that is, stability 75.0 mm by 50.0 mm 3 in. by 2 in. For the CSR tests, most companies crush as-received coke to yield a 19.0 mm by 22.0 mm34 in. by 78 in. product. Therefore, 57 kg 125 lb of gross sample is not necessarily required. In fact, Nippon S
36、teel Corporation, the originator of thetest, believes 10 kg 22 lb sublots of the gross sample is representative of the gross sample collected and is sufficient, with suitable crushing and sievingequipment, to yield enough 19 mm by 22 mm coke to provide repeatable results.48.5 Using a riffle splitter
37、, subdivide the 19.0 mm by 22.4 mm 34 in. by 78 in. coke into three test samples, each weighingapproximately 250 g 0.55 lb.8.6 Dry the test coke samples for a minimum of 2 h at 150 C. As a final step, dedust the dried test sample on a 19 mm 34 in.sieve prior to selecting pieces for analysis.4 Nishi,
38、 T., et al, Journal of the Fuel Society of Japan, Vol 61, No 668, 1982, pp 1066-1073.FIG. 2 Example of I-Type Coke Tumbler (Dimensions in mm)D5341/D5341M 17a39. Procedure9.1 From each test coke sample prepared in accordance with Section 8, randomly hand pick and accurately weigh to the nearest0.1 g
39、0.0002 lb, a 200 g 6 2.0 g 0.4409 lb 6 0.0044 lb sample for testing. Record the number of pieces selected from eachtest sample.9.2 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 verticall
40、y in the center of the coke bed with its tip 50 mm 2 in. from the bottom of the cokebed. A centering guide normally fastened to the center of the lid is used to ensure this positioning of the thermocouple tip.NOTE 5Variations in coke density may result in different total coke bed heights in the reac
41、tion vessel. Therefore, in situations where 50 mm 2 in.is not the center of the coke bed, adjust the thermocouple tip accordingly.9.3 Purge the reaction vessel for 5 min at 5 L/min to 10 L/min of N2 before loading the vessel into the furnace. Check for leaksin the assembly during this purge time.9.4
42、 Preheat the furnace to a temperature that will allow the sample, when the sample is loaded into the furnace, to reach 1100 C6 5 C in 30 min.9.5 Place the reaction vessel into the furnace and heat the sample to 1100 C in the atmosphere of N2 gas. Once the sampletemperature of 1100 C 6 5 C is reached
43、, soak the sample for 10 min in N2 gas for a total heat up time of 40 min. Then heatthe samples for 120 min in an atmosphere of CO2 gas, with a flow rate of 5.0 L/min 6 1.0 % (Note 6). The furnace temperaturemay be increased just prior to the introduction of the CO2 gas in order to compensate for a
44、temperature decrease as a result of theendothermic reaction. The temperature of 1100 C 6 5 C shall be regained within 10 minutes of the introduction of the CO2 gas.Maintain the coke bed temperatures at 1100 C 6 5 C during the test. (Fig. 3)9.6 After exactly 120 min exposure to CO2 gas, switch back t
45、o the N2 purge gas at 5 L/min to 10 L/min for 5 min to purge thereactor vessel of CO2. Subsequently, remove the reaction vessel from the furnace, and allow the sample temperature to cool to100 C.9.7 After cooling, remove the coke sample completely from the reaction vessel. Use a magnet to remove any
46、 metal ferrousflakes or scale from the sample and then weigh the coke to the nearest 0.1 g 0.0002 lb.9.8 Transfer the reacted coke to the strength after reaction tester and tumble for 600 revolutions in 30 min at 20 r/min61 r/min.9.9 After the 600 revolutions, remove all coke from the drum. Sieve th
47、e coke using a 9.5 mm 38 in. sieve. Weigh the cokeremaining on the 9.5 mm 38 in. sieve for calculation of CSR. Weigh the coke passing the 9.5 mm 38 in. sieve for checkingmaterial losses during tumbling.NOTE 6Since carbon monoxide (CO) is generated during the coke reactivity test, the test apparatus
48、should be placed in an area with proper ventilation.In addition, a CO monitoring device should be used to detect any unsafe buildup of CO gas.10. Number of Tests10.1 Reactivity and strength after reaction tests should be determined in duplicate for each coke sample.10.2 If the difference between the
49、 masses or weights of coke remaining after reaction with CO2 gas or after tumbling and sievingon the 9.5 mm 38 in. sieve exceed 10 g 0.022 lb, conduct one additional test and report the mean value of all three tests.FIG. 3 CSR Test ProcedureD5341/D5341M 17a411. Calculation11.1 For each test, calculate, to the nearest 0.1 %, the percentage of coke remaining after reaction in CO2 gas and that remainingafter tumbling on the 9.5 mm 38 in. sieve. Repo
