螯合剂对煤体性质的影响

煤矿进入深部开采后,煤体的力学性质发生改变,致使煤层的可注性降低,且煤层注水效果随着时间的推移逐渐变差。选用螯合剂增加煤层注水效果,通过实验分析发现:所注低渗透煤层中含有一定量的矿物质,螯合剂亚氨基二琥珀酸四钠(IDS)可以使矿物质解络成离子,使原本处于封闭状态的孔隙被疏通,水在煤层中的流动性增强;煤层中矿物质离子的浸出量随螯合剂IDS质量浓度增加逐渐增大, IDS用量在质量浓度为2 000 mg/L时性价比最高;IDS作用后煤样的冲击倾向性下降;含硫矿物质(例如黄铁矿)中金属离子被螯合后硫被释放,从源头上减少了硫的含量,同时IDS又是可降解环保型螯合剂,其使用对环境无毒性影响。煤层注水添加螯合剂为复合动力灾害防治提供参考。

Effects of chelating agent on coal properties

During the deep mining period of a coal mine, the mechanical properties of coal body have changed, resulting in the decrease of injectability of coal seam, and the effect of water injection in coal seam gradually deteriorates over time. In this research, chelating agent is selected to increase the effect of coal seam water injection. The experimental analysis has shown that the injected low permeability coal seam contains a certain amount of minerals which can be dissolved into ions by the chelating agent tetrasodium iminodiasuccinate (IDS), unclogging the originally closed pores, and enhancing the fluidity of water in the coal seam. The leaching amount of mineral ions in the coal seam increases gradually with the increase of the concentration of chelating agent IDS. When the concentration of IDS is 2 000 mg/L, the performance-cost ratio is the highest; the rock burst tendency of coal samples decreases by the action of IDS; the metal ions in sulfur-bearing minerals (such as pyrite) are released after chelation, which reduces the sulfur content from the source. At the same time, IDS is a degradable and environment-friendly chelating agent, providing assistance for environmental protection. Adding chelating agent to coal seam water injection can provide reference for the prevention and control of compound dynamic disasters.