In-situ modification in ultrafine crushing process of Taixi ultralow ash anthracite

Abstract Modification technology has become an important factor in realizing the preparation of coal-based materials considering the agglomeration phenomenon that often occurs during the ultrafine crushing process of coal. In this paper, Taixi anthracite was adopted as raw material, and maleic anhydride (MAH), ethylene diamine tetraacetic acid (EDTA) and dodecylbenzene sulfonic acid (DBSA) were respectively selected as modifiers to conduct in-situ surface modification on Taixi ultralow ash anthracite. The optimum proportions of MAH and DBSA were both 1%, and the corresponding particle size d 97 could decrease from 14.45 μm to 7.17 μm and 7.09 μm respectively, meanwhile with a good dispersity. In contrast, the aid-grinding and dispersion effects of EDTA in the ultrafine crushing process of Taixi anthracite were not as significant. The increasing proportions of these three modifiers have similar influence on DBP absorption value of Taixi coal powder, namely presenting an increasing trend first followed by a decreasing one. According to FTIR analysis, all these three modifiers could cover the particle surface of Taixi anthracite in the form of physical coating. After overall consideration, MAH was the best modifier for the in-situ surface modification of Taixi coal powder. Therefore, this study can provide technological support for follow-up studies on composition of coal-based PANI.