矸石山自燃治理及生态修复研究与应用

Research and application of spontaneous combustion control and ecological restoration of waste dump

潘西煤矿井下采掘生产过程中产生了大量的煤矸石,煤矸石提升到地面堆放场,日积月累慢慢堆积形成锥形矸石山体,裸露秃山无植被,垂直高度75 m,占地面积7.55万m2。矸石山体残留碎煤,含碳量20%~25%,矸石山富含硫磺石,含硫量3%~4%,为矸石自燃提供了物质条件。雨水顺着矸石裂隙流入到松散的矸石堆中,雨过天晴,在阳光照射下,水分蒸发,温度上升,随着时间的延长,慢慢在碎煤及硫磺石堆放集中的部位蓄热升温氧化自燃,山体内部形成高温点,直至自燃冒烟,烟雾缭绕弥漫扩散,散发CO、CO2、SO2氮氧化物等有毒有害气体,风化的碎粉碎屑在大风天气里极易扬尘,造成空气污染。雨水渗透矸石山渗到地表下,形成淋溶水,污染周边水源;雨水冲刷部分矸石流到周围田地,缓慢侵蚀周围农田。矸石山区域生态环境遭到极大污染破坏,危害周边居民身体健康,面临的环保压力越来越大,必须对矸石山自燃进行治理及生态修复。潘西煤矿通过探测矸石山表面及深部自燃状况,采取施工注水注浆钻孔进行注水降温注浆灭火,挖除刨平压实燃烧区,无机防灭火材料分层回填等综合治理技术,消除矸石山自燃危害,改善周边生态环境,取得了较好的效果。

A large amount of coal gangue were produced during the underground mining and production process in Panxi Coal Mine.The coal gangue was lifted to the ground dump site and accumulated gradually over time to form a cone-shaped gangue hill.The bare hill has no vegetation and the vertical height is 75 meters and it covers an area of 75500 m2.The gangue hill has residual coal with a carbon content of 20%~25%.The gangue dump is rich in sulfur with a content of 3%~4%,which provides material conditions for spontaneous combustion of gangue.The rainwater flows into the loose gangue piles along the gangue cracks.After the rain,the water evaporates and the temperature rises under sunlight.As time goes by,it slowly accumulates heat in the concentrated parts of the crushed coal and sulfur stone piles.Oxidation spontaneously ignites,forming high-temperature spots inside the mountain,until it spontaneously ignites and smokes,the smoke diffuses and emits toxic and harmful gases such as carbon monoxide,carbon dioxide,sulfur dioxide,nitrogen oxides,etc.and the weathered debris are easy to dust in windy weather,causing air pollution.The rainwater seeps into the gangue hill and seeps below the surface,forming leaching water and polluting the surrounding water sources;the rainwater washes away some of the gangue and flows to the surrounding fields and slowly erodes the surrounding farmland.The ecological environment of the gangue dump area has been greatly polluted and damaged,endangering the health of the surrounding residents,and facing increasing environmental pressure.Therefore,it is necessary to control the spontaneous combustion of waste dumpand ecological restoration.Panxi coal mine detected the surface and deep spontaneous combustion of gangue hill,adopted the construction water injection grouting boreholes for water injection,cooling,grouting,fire fighting,excavation and planing,compacting the combustion zone,and layered backfilling of inorganic fire-fighting materials and other comprehensive treatment technologies to eliminate the spontaneous combustion hazards of gangue dump and improved the surrounding ecological environment,which achieved good results.