Effect of carbonization temperature on the grindability of carbonaceous material produced from different coals

Abstract

Carbonization experiments were conducted on four kinds of sub-bituminous coal particles at a temperature range of 450-1200°C. The effect of treating temperature on the grindability of produced carbonaceous materials was investigated, and its mechanism was analyzed through various means. Results show that the grindability of all coals, whether caking or slightly-caking, exhibit the same variation trend with an increase in carbonization temperature. Moreover, the entire process can be divided into four stages. (1) After the most intense devolatilization stage, the grindability of carbonaceous material exhibited different degrees of increase compared with that of raw coal because of the development of a pore structure. (2) The first significant decrease in the grindability occurred from the plastic stage to the complete resolidification of the coal matrix.(3) After the aromatic polycondensation stage accompanied by a large amount of H 2 release, the coal molecular structure became compact, such that the grindability of semi-coke considerably decreased again. (4) At high temperatures, the coal matrix underwent graphitization, which changed semi-coke to coke. The molecular structure of coal became ordered, and the grindability decreased again. The analysis shows that a change in the internal chemical structure of carbonaceous material has a much more pronounced effect on grindability than a change in its pore structure, except in the first stage. The constant compaction and regularization of the coal molecular structure continued happening throughout the entire process and play a decisive role in the change in grindability.

Remediation with Semicoke-Preparation, Characterization, and Adsorption Application

“…A significant criterion for determining ‘low cost’ sorbents are their potential to be reused or regenerated, hence not requiring a refreshing material after every treatment application process [ 60 ]. This aspect of adsorbent technology defines its economic potential.…”