预防煤炭自燃的注砂技术实验研究

山砂是我国西北部矿区地表的主要自然资源之一,但如用其直接作为煤矿注浆防灭火的原料,不仅会造成输送管路的堵塞,还会引起输送管路的严重磨损。为此,首先研究了常见增稠剂羧甲基纤维素、聚丙烯酰胺和聚丙烯酸钠等对砂粒的悬浮性能,实验结果表明它们只能延缓砂粒的沉降。进而从理论上分析了砂粒悬浮的条件,发现具有一定屈服应力的假塑性流体特性的液体才能悬浮砂粒;并且悬浮砂粒粒径越大,所需屈服应力也越大。基于理论分析,研制了具有该特性的浆液,山砂在该浆液中不仅具有良好的悬浮性能,浆液还具有输送阻力小的特性。管道输送试验表明,浆液稳定性和流动阻力符合实际要求。

Experimental Study on the Sand Injection for Preventing Spontaneous Combustion of Coal

Sand is one of the rich natural resources on the earth surface in no rthwest China. But in coalmines, if the sand is used directly as the material in sand-injecting system without any additive, it will not only block up but also wear and tear the pipelines seriously. In this paper, the common thickening agen ts, such as sodium carboxymethyl cellulose, polyacrylamide and sodium polyacryla te, were tested first. The sedimentation velocity of sand was lowered, but sand could not be suspended. The suspension condition of sand was analyzed. The sand could be suspended in the fluid which is a pseudo-plastic fluid with yield stre ss. The larger the diameter of sand particulates, the higher the yield stress ne eded. According to theoretical analysis, this fluid was developed. The sand coul d be suspended in the liquid, and the fluid flows through the pipeline with a lo wer pressure loss. The experiment of fluid transportations by pipelines showed t hat its stability and flowing resistance accords with the practical requirements .