This paper is the result of mineral exploration engineering.

Objective Inertinite-rich coal is characterized by the high inertinite content, and several coal properties are personalized accordingly, which affecting its clean utilization. In this paper, we focus on both the determination of the time-space distribution of the inertinite-rich coals in China and the induction of the coal properties, clean potential and utilization mode of the low rank inertinite-rich coals in Northwest China.

Methods We sort out a large number of exploration data and research results, and coal macerals and coal properties data were analyzed and summarized. The determination of inertinite-rich coal's time-space distribution in China and their coal properties were based on the data. The clean potential and utilization mode of the low rank inertinite-rich coal in Northwest China were carried out along the coal properties combined with the indexes for various purposes.

Results It shows that the inertinite-rich coals are mainly distributed in the Early-Middle Jurassic in Northwest China. The low rank inertinite-rich coals in Northwest China are characterized by low ash, low sulfur, low harmful elements, low cohesiveness, low hydrogen content, low volatile matter, high carbon dioxide reactivity and high calorific value, among which, the hydrogen content, cohesiveness, volatile matter and carbon dioxide reactivity are obviously related to the high inertinite content. The coal properties show that the Jurassic coals in Northwest China are of high cleanliness and high calorific value, which is a high-quality power coal. The relatively low volatile matter and hydrogen content in the same coal rank make it not conducive to be used as coal for direct liquefaction. The low ash, low sulfur, low cohesiveness, strong reactivity with carbon dioxide are conducive to being used as coal for gasification, which is suitable for a variety of gasification processes. In addition, part of the low rank inertinite-rich coals represented by the northern part of Shaanxi Province are of high tar yield, which is suitable for low temperature retorting.

Conclusions The low rank inertinite-rich coals in Northwest China are suitable for power coal and gasification coal, and the tar-rich coal should be given priority to low temperature retorting.