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1、INTERNATIONAL STANDARD IS0 7404-3 Second edition 1994-l o-01 Methods for the petrographic analysis of bituminous coal and anthracite - Part 3: Method of determining maceral group composition MBthodes danalyse pktrographique des charbons bitumineux et de /anthracite - Partie 3: D wM is the mineral ma
2、tter content, as a mass per- centage, given by the equation w, = 1,08w,+ 0,55ws where w, is the sulfur content, as a mass per- centage on the air-dried basis. Equation (2) is based on assumed relative densities of 1,35 and 2,8 fo,r the macerals and mineral matter respectively. These equations have b
3、een found satisfactory in cer- tain coal basins but may not necessarily apply globally. It is essential for the user to establish suitable equations for the coals being analysed. 10.1 Repeatability limit The repeatability limit of the determination of the vol- ume percentage of a component is the va
4、lue of the difference between two single determinations, each based on the same number of points counted, carried out by the same operator on the same block using the same apparatus, below which 95 % of such differ- ences are expected to lie. The repeatability limit may be calculated from the formul
5、a I - (4 1 2 2 q where a, is the theoretical standard deviation. Provided that the operator makes negligible errors in classifying the macerals, the results of an analysis are subject to standard deviations calculable on the basis of the binominal distribution. Where p % of the total number of point
6、s counted, N, is registered for a given maceral group, the theoretical standard deviation, ut, of p is given by the equation a, = J p(100 -P) N Values based on counts of 500 points for the theor- etical standard deviation, coefficient of variation and repeatability calculated for a range of volume p
7、er- centages of a component are given in table 1, Table 1 - Theoretical standard deviation and repeatability limit of the percentage of a component, based on counts of 500 points Volume %, Standard Coefficient Repeatability deviation, of variation, limit, P ut 1000,/P N-l 2 2 CT, 5 20 50 80 95 1.0 2
8、0 1.8 9 z2 4,4 1,8 2,3 190 I,1 2.8 5.1 63 5.1 2,8 NOTE 3 For example, if the volume percentage of vitrinite in a sample is 80 %, then an operator can expect to obtain two results differing by less than 5,l percentage points (e.g. 78 % and 83 %I in 19 cases out of 20. Copyright International Organiza
9、tion for Standardization Provided by IHS under license with ISO Licensee=Defense Supply Ctr/9960866100 Not for Resale, 04/24/2007 10:04:18 MDTNo reproduction or networking permitted without license from IHS -,-,- 0 IS0 IS0 7404-3:1994(E) 10.2 Reproducibility limit The reproducibility limit of the de
10、termination of the volume percentage of a component is that value of the difference between two single determinations, each based on the same number of points counted, carried out by two different operators on two different subsamples taken from the same sample, using dif- ferent equipment, below wh
11、ich 95 % of such differ- ences are expected to lie. The reproducibility limit is given by the formula w J 2 2 co where ET, is the observed standard deviation. Values of the observed standard deviation normally exceed the values for the theoretical standard devi- ation given in table1 owing to the mi
12、sidentification of the macerals by different operators and to variation between subsamples; they have been found to vary from approximately 1,5 to 2,0 times the theoretical values, depending on the rank and the heterogeneity of the coal. 11 Test report The test report shall include the following inf
13、ormation: a) a reference to this part of IS0 7404; b) all details necessary for identification of the sam- ple; c) the name and address of the testing laboratory; d) date of test; e) the number of points counted; f) whether minerals were counted or ignored, or whether the mineral matter was calculat
14、ed, and (if calculated) the equation used; g) the results obtained; h) any other characteristics of the sample observed during the analysis that may be relevant to the use of the results. NOTE 4 It may also be useful to include nominal magni- fication, point count stage step size and line traverse s
15、pac- ing. 5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Defense Supply Ctr/9960866100 Not for Resale, 04/24/2007 10:04:18 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7404-3:1994(E) Q IS0 Annex A (informati
16、ve) Bibliography l International Handbook of Coal Petrography, published by the International Committee for Coal and Organic Petrology (ICCP). NOTE 5 The second edition (I 963), together with the first supplement (1971, corrected and revised in 19851, second supplement (1975) and third supplement (1
17、993) may be obtained from Professor D.G. Murchison, Fossil Fuels and Environmental Geochemistry, Drummond Building, Univer- sity of Newcastle, Newcastle-upon-Tyne, NE1 7RU, United Kingdom. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Defens
18、e Supply Ctr/9960866100 Not for Resale, 04/24/2007 10:04:18 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 7404-3: 1994(E) Q IS0 ICS 73.040.00 Descriptors: minerals and ores, solid fuels, coal, bituminous coal, anthracite, petrography, analysis methods, determination o
19、f content, organic matter, mineral matter, microscopic analysis. Price based on 6 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Defense Supply Ctr/9960866100 Not for Resale, 04/24/2007 10:04:18 MDTNo reproduction or networking permitted without license from IHS -,-,-