Preparation and Evaluation of Graphite from Coal-Derived Feedstocks

4 Preparation and Evaluation of Graphite From Coal-Derived Feedstocks 

In order to assess the loss of inorganic contaminants during graphitization, the ash composition of most of the graphites was analyzed by ICP-AES. The total ash contents of the WVU graphites are compared to those for the precursor calcined cokes in Table 22. Also included are data for H-451 and VNEA, which are the current qualified nuclear-grade graphites. 

2 Correlation cf graphite properties with processing methodology 

A key factor in the suitability of cokes for graphite production is their isotropy as determined by the coefficient of thermal expansion. After the calcined coke was manufactured into graphite, the axial CTE values of the graphite test bars were determined using a capacitance bridge method over a temperature range of 25 to 100°C. The results are summarized in Table 24. Also included in the table are bulk density measurement of calcined cokes and the resistivity values of their graphites. 

These results are significant since they show that the ultimate characteristics of the graphite product can be unequivocally controlled by the blendmg of pitches. Further, the results indicate that a single coal source could be utilized, by appropriate treatment, to provide a slate of different pitches and cokes. 

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