Study on the ideal location of a bottom drainage roadway

Abstract

The bottom drainage roadway plays a crucial role in preventing coal and gas outbursts by using underground gas drainage methods. Therefore, it is essential to select the ideal position of the bottom drainage roadway. In this paper use a combination of geological data and numerical simulation to study the ideal position of the bottom drainage roadway, we taking the gas drainage of the first workface of No. 3 coal seam in the Yuxi coal mine in China as an example. The geological study showed a limestone marker layer at an average vertical distance of 14 m from the first mining face. Using this marker layer, the bottom drainage roadway could be excavated without the risk of accidentally exposing the coal seam, and less crosscutting borehole drilling from the bottom drainage roadway would be required. Based on the needs of gas control, the layout of the bottom drainage roadway was selected as an external stagger type. Combined with the numerical simulation results, when located 20 m outside of the mining workface 'footprint' on the horizontal projection, the bottom drainage roadway was a sufficient distance from the stress concentration area during mining of workface 1301, which facilitated roadway maintenance. Furthermore, the length of the crosscutting boreholes is also relatively short, which reduces the amount and cost of drilling. The results of this study are expected to provide a reference for the selection of an ideal position of the bottom drainage roadway in field engineering.

Research on Directional Hydraulic Coal Cutting and Outburst Prevention Technology in Soft and Hard Composite Coal Seams

“…The energy structure of “rich coal, poor oil, and little gas” determines that coal will be the main energy source in China for a long time in the future. According to statistics, 48% of China’s coal mines are coal and gas outburst or high gas mines, and the number, scale, and losses caused by coal and gas outburst accidents are among the highest in the world. − …”

“…According to statistics, 48% of China’s coal mines are coal and gas outburst or high gas mines, and the number, scale, and losses caused by coal and gas outburst accidents are among the highest in the world. 1 − 6 …”

Optimal Process Parameters for Direct Carbothermal Reduction of Vanadium–Titanium Magnetite in a Rotary Kiln

“…[9][10][11][12] Currently, the comprehensive utilization of vanadium-titanium magnetite mainly focuses on the recovery of iron, vanadium, and titanium. [13][14][15][16][17] Representative methods for the comprehensive utilization of vanadium-titanium magnetite include blast furnace converters, prereduction furnaces, reduction grinding methods, and sodium extraction reduction furnaces, which can be classified into blast furnace converters and nonblast furnace methods, according to their characteristics. [18][19][20] Although the blast furnace converter method can recover iron and vanadium from vanadium-titanium magnetite concentrates, it still fails to address the problem of the slag becoming viscous when the TiO 2 content in the slag is greater than 25%.…”

“…Currently, the comprehensive utilization of vanadium–titanium magnetite mainly focuses on the recovery of iron, vanadium, and titanium. [ 13–17 ] Representative methods for the comprehensive utilization of vanadium–titanium magnetite include blast furnace converters, prereduction furnaces, reduction grinding methods, and sodium extraction reduction furnaces, which can be classified into blast furnace converters and nonblast furnace methods, according to their characteristics. [ 18–20 ]…”