1、BRITISH STANDARD BS 4262:1984 Method of specifying the technical quality of coke for use in blast furnaces UDC 662.749.2:669.162.2BS4262:1984 This British Standard, having been prepared under the directionof the Solid Mineral Fuels Standards Committee, waspublished under the authorityof the Board of
2、 BSI andcomes intoeffect on 28September1984 BSI 10-1999 First published February 1968 First revision September 1984 The following BSI references relate to the work on this standard: Committee reference SFC/7 Draft for comment 81/53503 DC ISBN 0 580 13944 1 Committees responsible for this British Sta
3、ndard The preparation of this British Standard was entrusted by the Solid Fuel Standards Committee (SFC/-) to Technical Committee SFC/7 upon which the following bodies were represented: British Steel Industry Coke Oven Managers Association National Coal Board Amendments issued since publication Amd.
4、 No. Date of issue CommentsBS4262:1984 BSI 10-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Sampling and sample preparation 1 3 Characteristics 1 4 Typical values and precision of the methods 2 Appendix A Guidance on the selection of tests for coke quality fo
5、r blast furnaces 4 Appendix B Extended Micum test 5 Appendix C Reactivity test 7 Figure 1 Relationship between10 4 /S m 2and drum revolutions 6 Figure 2 Typical arrangement of reactivity apparatus 9 Table 1 Details of drum tests 2 Table 2 Typical values of characteristics of coke andprecisionofthete
6、stmethods 3 Table 3 Relations between drum indices 4 Table 4 Typical extended Micum test data 5 Publications referred to Inside back coverBS4262:1984 ii BSI 10-1999 Foreword This revision of this British Standard has been prepared under the direction of the Solid Mineral Fuels Standards Committee. I
7、t supersedes the1968 edition which is withdrawn. The previous edition described a scheme which, if applied at producers and consumers works, enabled comparisons to be made by means of a “points value”, based upon approved systems of sampling analysis and testing of coke. The use of such a “points va
8、lue” concept is no longer current in the industry and this revision provides a reference standard for the technical assessment of coke when it is subjected to internal transfer and also in international trade. Attention is drawn to the provisions of the Health and Safety at Work etc. Act1974 and the
9、 need to ensure that appropriate precautions are taken to ensure the safety of personnel carrying out the methods of test referred to in this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their corr
10、ect application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to10, an inside back cover and a back cover. This standard has been updated (see copyrigh
11、t date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS4262:1984 BSI 10-1999 1 1 Scope This British Standard describes a method of specifying the technical quality of coke by listing the characteristics which are most widely used i
12、n the technical assessment of blast furnace coke. In the case of each characteristic specified, reference is made wherever possible to an authoritative source giving detailed procedures for the experimental techniques and evaluation of the appropriate characteristic. Information is given on typical
13、values for each characteristic and the precision of the test methods. It also provides guidance which may assist in the selection or choice of those properties which will be of most use in the assessment of coke for particular purposes (seeAppendix A). NOTEThe titles of the publications referred to
14、in this standard are listed on the inside back cover. 2 Sampling and sample preparation Sampling and sample preparation of coke for all purposes shall be carried out in accordance with the principles and particular requirements of BS1017-2. In some instances it is necessary to prepare coke having a
15、restricted range of particle size for a particular test. In such cases techniques of particle size reduction shall be such as to give the required yield of the specified size range. 3 Characteristics The technical quality of a consignment or lot of coke shall be specified by quoting the values obtai
16、ned from a sample (seeclause2) by the method stated for the following characteristics: a) total moisture content when tested in accordance with BS1016-2; b) ash and volatile matter content when tested in accordance with BS1016-4; c) sulphur content when tested in accordance with BS1016-7; d) phospho
17、rus content when tested in accordance with BS1016-9; e) size of the coke when determined in accordance with BS1016-18. In addition the values for one or more of the following characteristics shall be quoted: 1) mechanical strength when assessed(seeTable 1) either: i) in accordance with BS1016-13 (Mi
18、cum test 1)and Irsid drum test); or, ii) in accordance with JISK2151:1977 2)(JIS drum test); or, iii) in accordance with ASTM3402-8 3)(ASTM tumbler test); 2) shatter indices of coke of a specified size when assessed in accordance with BS1016-13; 3) bulk density, true relative density and apparent re
19、lative density when determined in accordance with BS1016-13; 4) reactivity when assessed in accordance with the method described in Appendix C. 1) Appendix B gives details of the extended Micum test. 2) Obtainable from Japanese Industrial Standards Committee, c/o Standards Department, Agency of Indu
20、strial Science and Technology, Ministry of International Trade and Industry1-3-1Kasumigaseki, Chiyodaku, Tokyo100, Japan. 3) Obtainable from ASTM,1916 Race Street, Philadelphia, Pa19103, USA.BS4262:1984 2 BSI 10-1999 Table 1 Details of drum tests 4 Typical values and precision of the methods An indi
21、cation is given in Table 2 of the order of values to be expected in the case of each characteristic noted. Further information regarding the reporting of results, change of base, rounding and precision may be obtained by reference to BS1016-16. Half-micum drum test JIS drum test ASTM tumbler test Dr
22、um dimensions Internal diameter Internal length Thickness of metal Lifting flights Number Depth of face mm mm mm mm 1 000 500 10 4 100 1 500 1 500 9 6 150 914 457 6 2 51 Rotating speed r/min 25 1 15 0.5 24 1 Test sample Mass Lump size Test sieve type Moisture kg mm % 25 20 round hole 40mm M 10 =%20m
23、m I 10 =%15mm 150 =%15mm 1400 Stability factor T 25 =%25mm Hardness factor T 6.3 =%6.3mm DI 30 15 DI 150 15BS4262:1984 BSI 10-1999 3 Table 2 Typical values of characteristics of coke and precision of the test methods Property Typical values Rounding Precision Repeatability Reproducibility Total mois
24、ture % 3 to 10 0.1 0.5absolute 0.7absolute Ash: dry basis % 6 to 12 0.1 75 75 50 60 0.1 0.1 2.0 units 2.0 units Shatter index S 40 80 0.1 6units for isolated consignments 5units for regular consignments NOTEThe Micum, Irsid, JIS, ASTM and shatter indices are dependent, to different extents, on the s
25、ize distribution of the bulk sample. As it is not possible to circulate a bulk sample to a number of laboratories without risk of breakage, and, therefore, alteration of the size distribution, no reproducibility tolerances have been given for these tests. DI 30 15 DI 150 15 BS4262:1984 4 BSI 10-1999
26、 Appendix A Guidance on the selection of tests for coke quality for blast furnaces The trend towards coke as opposed to coking coal becoming an internationally marketable product is growing and with it the requirement to meet critical quality specifications. Sampling of coke for proximate and ultima
27、te analyses presents no major difficulties; however, sampling and the selection of tests for assessing the physical quality of coke does present difficulties particularly where the coke has been or is to be subjected to considerable mechanical handling during transport and stocking. As a general rul
28、e the more rigorous the test, the lower the extent to which the test result is influenced. Micum test indices are extremely sensitive to the amount of handling to which the coke has been subjected, so much so that M 40indices may increase by6 to8 points between the coke ovens and the blast furnace.
29、The ASTM test being the most rigorous is barely influenced whilst the extended Micum slope is independent of any pretreatment. Physical quality specifications based upon drum tests should always specify in addition to the value of the index of quality the point in the handling system where the sampl
30、e is taken, e.g.point of loading or receipt. Metallurgical coke for use in the modern blast furnace also requires a narrow size range, e.g.30mm to70mm, consequently tests such as a Micum test based upon size greater than60mm round hole coke and to a lesser extent the ASTM test based upon size greate
31、r than50mm square hole coke are becoming less popular for assessing the quality of furnace coke since they are testing a less than representative sample of the coke. Where used, these tests are utilized for assessing coke oven operations rather than coke quality for ironmaking. For this reason the b
32、asic Micum test and the Irsid test use a sample of size greater than20mm. Other sizes of coke may be used for the Micum test when required but it is essential that the size used for the test should be reported with the result. In assessing the quality of coke for the blast furnace there is a growing
33、 tendency to move towards more rigorous tests based upon the generation of the fines fraction as an indicator of quality. These parameters are more indicative of the resistance to abrasion rather than the physical strength of the coke which has tended to be associated with the larger size indices an
34、d the coarse breakage. Many equations have been published relating the various drum indices (seeTable 3). Where a specific drum index is quoted this should wherever possible be measured and not calculated from another index. Extreme caution is advised in using these equations and their use should be
35、 restricted to the abrasion indices and to coke made from conventional wet charges. In addition to assessing the quality of coke at ambient conditions there is a tendency to include high temperature test properties such as reactivity to carbon dioxide and the assessment of physical quality following
36、 reaction with carbon dioxide. Table 3 Relations between drum indices Reporter Joh et al a Miyazu et al b =(17.14M 40 ) 0.39 T 25 =2.62M 10 +73.9 =1.54M 10 +10.3 T 25 = M 40 20.1 T 6 =0.28M 10 +68.6 =(42.0T 25 ) 0.198 M 40 =96.08+1.85 M 40 =55.18+0.24 M 40 =57.73+0.31T 25 M 10 =62.970.58 M 10 =14.56
37、0.07 T 25 =53.78+0.13 a Joh, H and G da, S.Yawata Technical Report. 1970(233)116124. b Miyazu T et al Nippon Kokan Technical Report (6overseas) Dec1970, pp113. DI 30 15 DI 30 15 DI 30 15 DI 30 15 DI 150 15 DI 30 15 DI 150 15 DI 150 15BS4262:1984 BSI 10-1999 5 Appendix B Extended Micum test B.1 Gener
38、al A Micum test, known as the extended Micum test, can be carried out by repeating the test procedure and determining the size analysis of the sample after each test cycle, e.g.100,200,300,500,700,900 drum revolutions. B.2 Apparatus As described in4.3.2 of BS1016-13:1980. B.3 Test sample As describe
39、d in 4.3.3 of BS1016-13:1980. B.4 Procedure Carry out this variant of the Micum test by using the procedure described in4.3.4.2 of BS1016-13:1980. After the coke sample is sized following100drum revolutions, carefully return the whole mass of the sample to the drum and rotate for a further test cycl
40、e and again remove and resize. Repeat this procedure until the predetermined test cycles are completed. NOTEIt is impossible to carry out an extended Micum test without losing some of the sample which is reduced to a particle size of less than1min. It is also impossible to reject the test if the los
41、s at any stage exceeds the limit laid down in4.3.4.3 of BS1016-13:1980. Great care therefore is necessary to ensure that loss in mass at each stage of the extended test is kept to a minimum. All losses are added to the mass of the smallest fraction. B.5 Calculation of results Convert the cumulative
42、mass of each fraction, in kilograms and weighed to the nearest25g, in each testcycle to a percentage by multiplying by four, and tabulate the results cumulatively. Calculate the arithmetic mean size of the sample, after each test cycle using the formula given in4.2.5 of BS1016-13:1980. Inspect the d
43、ata by plotting the reciprocal of the square of the arithmetic mean size (multiplied by10 4for convenience) against the number of drum revolutions. An example of the results of a typical extended Micum test, using a sample containing all sizes greater than20mm, is given in Table 4 and shown graphica
44、lly in Figure 1. Table 4 Typical extended Micum test data Drum revolutions 0 100 200 300 500 700 900 Size analysis: % cumulative 100mm 80mm 60mm 40mm 30mm 20mm 10mm 10mm Arithmetic mean size S m (mm) 1.4 14.0 43.6 84.1 94.8 100.0 100.0 0.0 58.90 2.882 6.4 21.1 66.6 83.0 90.9 93.6 6.4 47.84 4.369 5.4
45、 20.2 60.0 78.3 87.4 90.0 10.0 44.69 5.007 3.7 17.8 55.0 74.6 84.1 87.4 12.6 42.16 5.625 2.6 13.0 47.5 67.6 78.6 82.1 17.9 38.08 6.896 2.0 8.8 42.1 61.6 73.7 77.8 22.2 34.78 8.266 1.1 6.8 37.8 57.5 69.2 74.1 25.9 32.33 9.567 10 4 S m 2 -BS4262:1984 6 BSI 10-1999 From Table 4: a) Micum indices 20mmM
46、40 =66.6 20mm M 10 =6.4 If required the M 40of a sample of greater than60mm coke can be estimated, with an accuracy of 5.0units, by taking account of the proportion of the greater than20mm sample which is greater than40mm at zero revolutions of the drum. Hence: b) Irsid indices I 20 =78.6 I 10 =17.9
47、 Figure 1 Relationship between 10 4 /S m 2 and drum revolutions 60 mm M 40 20 mm M 40 % 40 mm in 20 mm sample -100 = 66.6 84.1 -10079.2 5.0 = =BS4262:1984 BSI 10-1999 7 From Figure 1 the equation for the best straight line relationship between the reciprocal of the square of the arithmetic mean size
48、 and the number of drum revolutions is derived by graphical or mathematical means. Hence: y =0.0065x+3.70 then: Micum slope= intercept=3.70 fissure free size=52.0mm From Table 4 and Figure 1: The relationship between the extended Micum slope (M s ) and M 30after900 revolutions () for36 blast furnace
49、 cokes with extended Micum slopes in the range0.43 to0.93 is given by the equation: M s =1.85 (95% confidence limits 0.10) If this equation is used, the long and tedious procedure for carrying out the extended Micum test may be avoided. Appendix C Reactivity test C.1 Principle A mass of coke of a specified size is heated in an atmosphere of carbon dioxide and the loss in mass determined. The re
