1、Designation: D5341 99 (Reapproved 2010)1D5341/D5341M 14Standard Test Method forMeasuring Coke Reactivity Index (CRI) and Coke StrengthAfter Reaction (CSR)1This standard is issued under the fixed designation D5341;D5341/D5341M; the number immediately following the designation indicatesthe year of ori
2、ginal 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 NOTEAdded research report information to Section 11 editorially in Septe
3、mber 2010.1. Scope1.1 This test method, patterned after the Nippon Steel test procedure, describes the 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
4、 referred to as an I-tester.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. The values given inparentheses are for information only. stated in each system may not be exact equivalents; therefore, each system shall be usedindependently of th
5、e other. Combining values from the two systems may result in non-conformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health pr
6、actices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 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 a
7、n Interlaboratory Study to Determine the Precision of a Test Method2.2 British Carbonization Research Association 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 dri
8、ed coke of designated origin and size is reacted with CO2 gas in a retort at a specified elevated temperaturefor a specified length of time. Two indices, coke reactivity index (CRI) and coke strength after reaction (CSR), are determinedusing the reacted coke residue. The weight loss after reaction d
9、etermines the CRI. The weight retained after sieving the tumbledreacted coke in a designated 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
10、abrasion asthey rub together and against the walls of the furnace. These concurrent processes 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 metho
11、d is designed to measure indirectly this behavior of coke in the blast furnace.5. Apparatus5.1 Electric Furnace (Fig. 1), capable of housing the reaction vessel assembly containing the coke sample and providing auniform temperature of 1100 6 5C in the assembly. Furnace dimensions do not impact the t
12、est results and may vary from 2401 This test 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 May 1, 2010Sept. 1, 2014. Published May 2010September 2014.
13、 Originally approved in 1993. Last previous edition approved in 20042010 asD5341 99 (2004).(2010)1. DOI: 10.1520/D5341-99R10E01.10.1520/D5341_D5341M-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Sta
14、ndardsvolume information, refer to the standards 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 o
15、f what changes have been made to the previous 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 considere
16、d the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1to 1035 mm 9 12 to 40 34 in. in length and 76.2 to 88.9 mm 88.9 mm 3 to 312 in. in outside diameter. However, it is preferablethat the furnace have independently
17、controlled heating in three zones to achieve uniformity of heating in the retort and that thiscontrol be achieved with a programmable controller.5.2 Reaction Vessel (Fig. 1), constructed of a heat-resistant steel or nickel alloy to the dimensions required to fit snugly insidethe electric furnace sel
18、ected for use (Note 1). The coke to be tested sits on a porous plate in the reaction vessel. Below this porousplate, a gas preheater, such as a bed of ceramicAl2O3 balls sitting on a second perforated plate, diffuse the nitrogen (N2) and carbondioxide introduced into the vessel up through the coke b
19、ed during the course of the test. The gas enters through inlets and exitsthrough outlets varying from 6 to 6 to 15 mm 14 to 58 in. in inside diameter and positioned at the top and bottom of the reactionvessel. During the test, it is important that no backpressure be detected when gas enters or exits
20、 through these inlets or outlets. Thereaction vessel is positioned such that the coke sample contained in the vessel on top of the ceramic Al2O3 balls is in the centerof the controlled temperature zone in the furnace.NOTE 1Inconel 601 is recommended over stainless steel. Inconel 601 does not leave s
21、cale, that, if not properly removed, can alter a coke sampleweight after the test.5.3 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 f
22、low can cause variability inthe test results. Gas pressures through the flowmeters should be maintained at the manufacturers calibration specification.5.4 Thermocouple (Fig. 1), of the K, S, or R type normalized at 20 to 21C and enclosed in a heat-resistant steel or nickel alloyor ceramic protection
23、 tube placed in the center of the coke sample in the reaction vessel. A centering pipe or tube also made ofheat-resistant material is used to guide the thermocouple into its proper location in the coke bed.5.5 Sieves, used for sieving the coke during its preparation for reactivity testing and after
24、tumbling for strength after reactiontesting. Square mesh sieves having 22.4-, 19.0-,22.4- 78-in., 19.0- 34-in., and 9.5-mm 38-in. actual openings between the wiresare to be used. Standard test sieves that conform to Specification E11 should always be used.5.6 Balance, capable of weighing up to 25 kg
25、 55.1 lbs and sensitive to 0.1 g (0.000 22 lbs).0.000 22 lbs.5.7 Coke Strength After Reaction Tumbler (Fig. 2), consisting of a cylindrical chamber with an internal length of 700 6 10 mm27 58 6 38 in. and an internal diameter 130 6 5 mm, mm 5 18 6 12 in., with end caps of 10-mm thickness or more (No
26、te 2).This cylindrical chamber is attached to its longitudinal center to an electric motor fitted with a direct drive fixed gearbox, a drivebelt, or, preferably, a hydraulic drive set for a revolving rate of 20 6 1 r/min (Note 3). A revolution counter is fitted so that thepower is cut off when the c
27、ylinder has revolved 600 times in 30 min.NOTE 2Mild carbon steel should be selected to fabricate this tumbler apparatus.NOTE 3Most Japanese publications refer to this as an I600/10 test.6. Sampling6.1 The gross sample of coke shall be collected in accordance with Test Method D346.6.2 For the standar
28、d procedure, the quantity must be not less than 57 kg (125 lbs).125 lbs.FIG. 1 Example of Reactivity Test Apparatus (Dimensions in mm)D5341/D5341M 1427. Preparation of Sample7.1 Sieve the gross sample at 25.0 mm (1 in.)1 in. and discard the undersize.7.2 With suitable crushing equipment, preferably
29、a jaw or roll crusher, reduce the size of all of the remaining plus 25.0 mm (1in.)1 in. to pass a 22.4-mm (78-in.)-in. sieve opening.7.3 Sieve the crushed sample using a 22.4-mm (78-in.)-in. sieve placed on top of a 19.0-mm (34-in.)-in. sieve. Discard theminus 19.0-mm (34-in.)-in. coke, and retain t
30、he 22.4- by 19.0-mm (78- by - by 34-in.)-in. fraction for testing.7.4 The size reduction of the plus 25.0 mm (1 in.)1 in. should be accomplished in stages by recrushing any plus 22.4-mm(78-in.)-in. coke remaining after each subsequent double sieving step until there is no oversize retained on the 22
31、.4-mm(78-in.)-in. sieve. The opening to the crusher should be set such that the gross sample yields at least 10 % of 19.0- by 22.4-mm(34- 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
32、natural sample fortesting, that is, stability 75.0 by 50.0 mm (33 by 2 in.).in. For the CSR tests, most companies crush as-received coke to yield a 19.0- by 22.0-mm 34-by 78-in. product. Therefore, 57 kg (125 lbs)125 lbs of gross sample is not necessarily required. In fact, Nippon Steel Corporation,
33、 the originator ofthe test, believes 10-kg (22-lbs)22-lbs sublots of the gross sample is representative of the gross sample collected and is sufficient, with suitable crushingand sieving equipment, to yield enough 19- by 22-mm coke to provide repeatable results.47.5 Using a riffle splitter, subdivid
34、e the 19.0- by 22.4-mm (34- by 78-in.)-in. coke into three test samples, each weighingapproximately 250 g (0.55 lbs).0.55 lbs.7.6 Dry the test coke samples to less than 1 % moisture at 150C for 2 h.8. Procedure8.1 From each test coke sample prepared in accordance with Section 7, randomly hand pick a
35、nd accurately weigh to the nearest0.1 g (0.0002 lb),0.0002 lb, a 200- 6 2.0-g 0.4409 6 0.0044 lb sample for testing. Record the number of pieces selected fromeach test sample.8.2 Before the reaction vessel is put into the electric furnace, place the weighed sample in the reaction vessel in a manner
36、asto ensure that the 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
37、 in different total 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.8.3 Purge the reaction vessel for 5 min at 5 to 10 L/min of N2 before loading the vessel into the furnace. Check for leaks
38、 inthe assembly during this purge time.8.4 Preheat the furnace to a temperature that will allow the sample, when the sample is loaded into the furnace, to reach 11006 5C in 30 min.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 Co
39、ke Tumbler (Dimensions in mm)D5341/D5341M 1438.5 Place the reaction vessel into the furnace and heat the sample to 1100C in the atmosphere of N2 gas. Once the sampletemperature of 1100 6 5C is reached, soak the sample for 10 min in N2 gas for a total heat up time of 40 min. Then heat thesamples for
40、120 min in an atmosphere of CO2 gas, with a flow rate of 5.0 L/min 6 1.0 % (Note 6). Maintain the coke bedtemperatures at 1100C 6 5C during the test. (Fig. 3)8.6 After exactly 120-min exposure to CO2 gas, switch back to the N2 purge gas at 5 to 10 L/min for 5 min to purge the reactorvessel of CO2. S
41、ubsequently, remove the reaction vessel from the furnace, and allow the sample temperature to cool to 100C.8.7 After cooling, remove the coke sample from the reaction vessel and weigh the coke to the nearest 0.1 g (0.0002 lbs).0.0002lbs.8.8 Transfer the reacted coke to the strength after reaction te
42、ster and tumble for 600 revolutions in 30 min at 20 6 1 r/min.8.9 After the 600 revolutions, remove all coke from the drum. Sieve the coke using a 9.5-mm (38-in.)-in. sieve. Weigh the cokeremaining on the 9.5-mm (38-in.)-in. sieve for calculation of CSR. Weigh the coke passing the 9.5-mm (38-in.)-in
43、. sieve forchecking material losses during tumbling.NOTE 6Since carbon monoxide (CO) is generated during the coke reactivity test, the test apparatus 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.9. Numbe
44、r of Tests9.1 Reactivity and strength after reaction tests should be determined in duplicate for each coke sample.9.2 If the difference between the weights of coke remaining after reaction with CO2 gas or after tumbling and sieving on the9.5-mm (38-in.)-in. sieve exceed 10 g (0.022 lbs),0.022 lbs, c
45、onduct one additional test and report the mean value of all threetests.10. Calculation10.1 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.)-in. sieve. Report the average of these values
46、for the two or more tests as the CRI and CSRvalues, respectively.10.1.1 Calculations are made as follows:CRI5A2BA 3100 (1)CSR5CB 3100 (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 tumbling.C =
47、 sample weight of +9.5-mm 38-in. material after tumbling.FIG. 3 CSR Test ProcedureD5341/D5341M 14411. Precision and Bias511.1 PrecisionThe relative precision of this test method, characterized by repeatability (Sr,r) and reproducibility (SR,R) hasbeen determined for the following materials to be:CRI
48、Material Average Sr SR r RSample 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 3.46 2.36 9.70CSRMaterial Average Sr SR r RSample 4 26.94 1.21 4.46 3.36 12.49Sample
49、 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 4.90The relative precision of this test method for the determinationindividual determinations of the CRI and CSR of coke coversisshown in Table 1the range of. The precision characterized by the repeatability (Sr 20 to 50 for CRI and 27 to, r) and reproducibility(SR 66 for CSR., R) are d