China’s coking coal resources are scarce, and maximizing the recycling of these resources is the primary objective of coal processing and utilization. The embedding features of inorganic minerals within coking middling coal resources are an inherent factor influencing their liberation and separation efficiency. However, current research lacks a systematic investigation into how the embedding features of inorganic minerals in coking middling coal affect their liberation characteristics and flotation separation performance. This study examines three Chinese coking middling coal samples with distinct embedding features. Based on quantitative characterization of inorganic mineral embedding, grinding tests with varying durations and flotation separation tests on post-grinding products were conducted. Liberation and separation efficiencies were evaluated to explore the influence of inorganic mineral embedding on liberation degree and the subsequent impact of the liberation degree on flotation performance. The results indicate that the three coking middling coal samples with different embedding features exhibit significant differences in the dissociation behavior between inorganic minerals and organic matter. The particle size (D) of inorganic mineral phases is the primary factor influencing the liberation degree of inorganic minerals, while the complexity of intergrowth between inorganic minerals and organic matter (CIG) is a secondary factor. The CIG is the primary factor affecting the liberation of organic matter. As the liberation of inorganic minerals and organic matter increases, the separation efficiency improves for the Liuwan middling coal samples, whereas it deteriorates for the Shaqu and Changzhi samples.
Hua et al. (Wed,) studied this question.