1、Designation: D5341/D5341M 14D5341/D5341M 17Standard 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 the
3、 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 reg
4、arded 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 s
5、afety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.4 This international standard was developed in accordance with internatio
6、nally 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 Documents2.1 ASTM Standards:2D346 Practic
7、e 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 Association Report:Carbonizatio
8、n 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 temperaturefor a specified length o
9、f 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 designated number of revolutions over
10、 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 processes physically weaken and che
11、mically 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 test method is under the jurisdic
12、tion 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 Sept. 1, 2014Aug. 1, 2017. Published September 2014September 2017. Originally approved in 1993. Last previous edition approved in 20
13、102014as D5341 99 (2010)D5341 14.1. DOI: 10.1520/D5341_D5341M-14.10.1520/D5341_D5341M-17.2 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 standards Document Summa
14、ry 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 previous version. Becausei
15、t 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 International, 100 Barr
16、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 % by volume, dry with
17、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 C65C5 C in the assembly. Furnace dimensions do not impact the test results and may vary from240
18、 to 1035 mm 9 The position of the coke sample contained 12 to 40 34 in. in length and 76.2 to 88.9 mm 3 to 3in the vesselassembly when housed 12 in. in outside diameter. However, it in the furnace shall be in the center of the controlled temperaturezone. It is preferable that the furnace have indepe
19、ndently controlled heating in three zones to achieve uniformity of heating in theretort and that this control be achieved with a programmable controller.6.2 Reaction Vessel (Fig. 1), constructed of a heat-resistant steel or nickel alloy to(see Note 1the dimensions required to ) withan internal diame
20、ter of 78 mm 6 1 mm 3.07 in. 6 0.039 in. and designed to fit snugly inside the electric furnace selected foruse (use. Note 1). The coke to be tested sits on a porousperforated plate in the reaction vessel. Below this porousperforated plate,a gas preheater, such as a bed of ceramic Al2O3 balls sittin
21、g on a second perforated plate, is used to diffuse the nitrogen (N2) andcarbon dioxide (CO2) introduced into the vessel up through the coke bed during the course of the test. The gas enters through inletspositioned at the bottom of the reaction vessel and exits through outlets varying from 6 to at t
22、he top of the reaction vessel varyingfrom 6 mm to 15 mm 14 in. to 58 in. in inside diameter and positioned at the top and bottom of the reaction vessel. diameter.During the test, it is important that no backpressure be detected when gas enters or exits through these inlets or outlets. The reactionve
23、ssel is positioned such that the coke sample contained in the vessel on top of the ceramic Al2O3 balls is in the center of thecontrolled temperature zone in the furnace. The reaction vessel shall be inspected prior to each use for wear, cracks, ordeterioration. Clean and remove scale that could cont
24、aminate the test sample if present. The vessel should also be checked for leaksprior to initial use and 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 we
25、ight 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 th
26、rough 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 R
27、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 t
28、he coke bed.FIG. 1 Example of Reactivity Test Apparatus (Dimensions in mm)D5341/D5341M 1726.5 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- 22.4 mm 78-in., 19.0- in., 19.0 mm 34-i
29、n., and 9.5-mm in., and 9.5 mm 38-in. in.actual openings between the wires are to be used. Standard test sieves that conform to Specification E11 should always be used.6.6 Balance, capable of weighing up to 25 kg 55.1 lbslb and sensitive to 0.1 g 0.000 22 lbs.lb.6.7 Coke Strength After Reaction Tumb
30、ler (Fig. 2), consisting of a cylindrical chamber with an internal length of 700700 mm6 10 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 10 mmthickness or more (Note 2). This cylindrical chamber is attached to its longitudinal center to an ele
31、ctric motor fitted with a directdrive fixed gearbox, a drive belt, or, preferably, a hydraulic drive set for a revolving rate of 20 r/min 6 1 r/min (Note 3). Arevolution counter is fitted so that the power is cut off when the cylinder has revolved 600 times in 30 min.NOTE 2Mild carbon steel should b
32、e selected to fabricate this tumbler apparatus.NOTE 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 lbs.lb.8. Prepa
33、ration of Sample8.1 Sieve the gross sample at 25.0 mm 1 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 mm25.0 mm 1 in. to pass a 22.4-mm22.4 mm 78-in. in. sieve opening.8.3 Sieve the crushed samp
34、le using a 22.4-mm 22.4 mm 78-in. in. sieve placed on top of a 19.0-mm 19.0 mm 34-in. in.sieve. Discard the minus 19.0-mm 19.0 mm 34-in. in. coke, and retain the 22.4- by 19.0-mm 22.4 mm by 19.0 mm 78- by in.by 34-in. in. fraction for testing.8.4 The size reduction of the plus 25.0 mm 1 in. should b
35、e accomplished in stages by recrushing any plus 22.4-mm 22.4 mm78-in. in. coke remaining after each subsequent double sieving step until there is no oversize retained on the 22.4-mm 22.4 mm78-in. in. sieve. The opening to the crusher should be set such that the gross sample yields at least 10 % of 1
36、9.0- by 22.4-mm19.0 mm by 22.4 mm 34- in. by 78-in. in. test coke (Note 4).NOTE 4The size of the sample required for most coke tests depends on collecting sufficient received material to have sufficient natural sample fortesting, that is, stability 75.0 mm by 50.0 mm 33 in. by 2 in. For the CSR test
37、s, most companies crush as-received coke to yield a 19.0- by 22.0-mm19.0 mm by 22.0 mm 34- in. by 78-in. in. product. Therefore, 57 kg 125 lbslb of gross sample is not necessarily required. In fact, Nippon SteelCorporation, the originator of the test, believes 10-kg 22-lbs 10 kg 22 lb sublots of the
38、 gross sample is representative of the gross sample collectedand is sufficient, with suitable crushing and sieving equipment, to yield enough 19- by 22-mm 19 mm by 22 mm coke to provide repeatable results.48.5 Using a riffle splitter, subdivide the 19.0- 19.0 mm by 22.4-mm22.4 mm 34- in. by 78-in. i
39、n. coke into three test samples,each weighing approximately 250 g 0.55 lbs.lb.4 Nishi, 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 1738.6 Dry the test coke samples to less than 1 % moisture a
40、t 150C for a minimum of 2 h at 150 C. As a final step, dedust thedried test sample on a 19 mm 34for 2 h. in. sieve prior to selecting pieces for analysis.9. Procedure9.1 From each test coke sample prepared in accordance with Section 78, randomly hand pick and accurately weigh to the nearest0.1 g 0.0
41、002 lb, a 200- 6 2.0-g 0.4409 6 0.0044 lb 200 g 6 2.0 g 0.4409 lb 6 0.0044 lb sample for testing. Record thenumber of pieces selected from each test 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 th
42、e thermocouple sits vertically 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
43、 coke bed heights in the reaction 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 assemb
44、ly during this purge time.9.4 Preheat the furnace to a temperature that will allow the sample, when the sample is loaded into the furnace, to reach11001100 C 6 5C5 C in 30 min.9.5 Place the reaction vessel into the furnace and heat the sample to 1100C1100 C in the atmosphere of N2 gas. Once thesampl
45、e temperature of 11001100 C 6 5C5 C is reached, soak the sample for 10 min in N2 gas for a total heat up time of 40min. Then heat the samples for 120 min in an atmosphere of CO2 gas, with a flow rate of 5.0 L/min61.0 % (Note 6). The furnacetemperature may be increased just prior to the introduction
46、of the CO2 gas in order to compensate for a temperature decrease asa result of the endothermic reaction. The temperature of 1100 C 6 5 C shall be regained within 10 minutes of the introductionof the CO2 gas. Maintain the coke bed temperatures at 1100C1100 C 6 5C5 C during the test. (Fig. 3)9.6 After
47、 exactly 120-min120 min exposure to CO2 gas, switch back to the N2 purge gas at 5 L/min to 10 L/min for 5 min topurge the reactor vessel of CO2. Subsequently, remove the reaction vessel from the furnace, and allow the sample temperature tocool to 100C.100 C.9.7 After cooling, remove the coke sample
48、completely from the reaction vessel and vessel. Use a magnet to remove any metalferrous flakes or scale from the sample and then weigh the coke to the nearest 0.1 g 0.0002 lbs.lb.9.8 Transfer the reacted coke to the strength after reaction tester and tumble for 600 revolutions in 30 min at 20 r/min6
49、1 r/min.9.9 After the 600 revolutions, remove all coke from the drum. Sieve the coke using a 9.5-mm 9.5 mm 38-in. in. sieve. Weighthe coke remaining on the 9.5-mm 9.5 mm 38-in. in. sieve for calculation of CSR. Weigh the coke passing the 9.5-mm 9.5 mm38-in. in. sieve for checking material losses during tumbling.NOTE 6Since carbon monoxide (CO) is generated during the coke reactivity test, the test apparatus should
