Measurement And Automation Of Microscopic Coal Petrography Parameters

When judging the coal by the measurement result of the coal’s vitrinite reflectance, the data of vitrinite content is needed for the correction. The vitrinite content can be got according to the measurement method from existing national standard, but it is too laborious to meet the measurement condition in the national standard, therefore most of the coking enterprises rarely perform the measurement of microscopic coal petrography parameters, which causing the deviation is inevitably brought into the measurement result when the enterprise is in the application of coal’s vitrinite reflectance. Given the laborious problems when measuring the coal’s vitrinite content by using the current national standard, this research explores a new method to get the vitrinite content of coal:configuring the mixed coal by the bituminous coal sample in which the vitrinite content is known and the other coal sample with unknown vitrinite content according to the fixed ratio, then measuring the coal blending to get the vitrinite reflectance, and peeling the reflectivity distribution peak of each single coal in the coal blending, finally we can calculate the vitrinite content of the coal sample based on the ratio of peak area. The linear correlation equation of results between the new method and national standards of10mixed coal is:ymeasured=1.5108xnational standard-44.356, and its correlation coefficient R is0.8770. When the confidence level α=0.01(R=0.7079), the linear fitting results are validated by the correlation test, which shows that the correlativity is very remarkable. The new method to measure the vitrinite reflectance of coal, and to get the vitrinite content of them at the same time, which can save time and effort compared to national standards. It has important significance to evaluate and eliminate the creating variances when using the vitrinite reflectance of coals such as coal blending for coking and so on.There is correlation between the measurement results of vitrinite reflectance by automatic and semi-automatic methods, no matter what it is single coal or blended coal, the enterprises always use one linear fitting equation to calculate. But the nature of single coal and blended coal is different, such as the coal rank, the vitrinite reflectance is more accurate for the single coal, and it is only one indicator for the mixed coal. So in this case, this paper more precisely discusses the correlation of the two kinds of measurement results, and the corresponding fitting equations can be got respectively both for the single coal and the blended coal. Using HD full automatic microscope photometer to respectively automatically and semi-automatically measure the vitrinite reflectance and standard deviation of32kinds of single coal and24kinds of mixed coal, Statistics of the vitrinite reflectance and the standard deviation of each single coal by automatic and semi-automatic methods, and perform the linear fitting of the measurement results. For single coal, the linear correlation equation of vitrinite reflectance of the single coal through automatic and semi-automatic measurement results is:yauto=0.9955xsemi-auto-0.0656, and its correlation coefficient R is0.9851; the linear correlation equation of standard deviation through automatic and semi-automatic measurement results is:yauto=0.8999Xsemi-auto-0.0046, and correlation coefficient R is0.7173. When the confidence level a=0.01(R=0.4487), the linear fitting results are validated by the correlation test. For mixed coal, the linear correlation equation of vitrinite reflectance of the mixed coal through automatic and semi-automatic measurement results is:yauto=1.0057xsemi-auto-0.0824, and its correlation coefficient R is0.9607; the linear correlation equation of standard deviation through automatic and semi-automatic measurement results is:yauto=0.9948xsemi-auto-0.0044, and correlation coefficient R is0.9839. When the confidence level α=0.01(R=0.5368), both linear fitting results are validated by the correlation test. Through the statistical analysis of the measurement results of the single coal and mixed coal, the results are more accurate between the conversions from the different fitting equations and the average random vitrinite reflectance and the standard deviation by semi-automatic and automatic methods.No matter which method is adopted, there are still corresponding advantages and disadvantages when preparing the coal sample. The research also explores the problem that different caking agents may make the differences in the measurement results. Using HD full automatic microscope photometer to measure the random vitrinite reflectance of polished grain mounts making from three kinds of different caking agents, and the measurement conditions are as following:the total points by automatic measurement is10000, and the points by semi-automatic measurement is100. The analysis of results shows that the polished grain mounts from three kinds of caking agents have the same effect, and they almost have no influence on the measure results. We can choose different caking agents according to the specific situation in practical application.