Quantitative determination of the effect of moisture and freeze / thaw cycles on coal gaugue decay rate in severe cold mining areas
CHENG Wei1,2 ,GUO Haiqiao3 ,SHANG Zhi4 ,MU Shouguo1,2 ,BIAN Zhengfu1,2 ,LEI Shaogang1,2
酷寒矿区表土瘠薄,陆地覆被破坏后可利用表土稀缺是制约煤矿区土地复垦的重要因素之一,难以获得足够的可用表土不仅直接影响到煤矿土地复垦效果,同时也限制煤矿区可持续发展的进程。因此在缺土区拓展可利用表土来源不仅是煤炭土地复垦中亟待解决的生产问题,也是一个重要的科学问题。煤矸石是矿产资源开发利用的副产物,也是潜在的表土来源之一。针对特殊环境下的土地复垦需要,以酷寒矿区未风化煤矸石为研究对象,从水分变化、冻融循环单独作用和水分-冻融循环叠加作用于煤矸石的角度进行试验设计,分析了3类14种处理下煤矸石风化崩解的差异性。结果表明:水分-冻融循环处理下煤矸石风化崩解速率明显大于水分和冻融循环单独处理,风化崩解速率差异较大。运用聚类分析把煤矸石14 种处理下的崩解速率分为2类,2类间的崩解速率差异显著,引起风化崩解速率差异显著的因素主要是较大的温差变化引起水分和盐分结晶膨胀。其中饱和含水-冻融循环组风化崩解速率大于非饱和水分组,大温差组大于小温差或恒温组。指出了温差变化中冰晶作用的存在引起了煤矸石的快速崩解主导因素。本研究揭示了水分作用对煤矸石风化崩解的影响大于温度用冻融循环有利于煤矸石风化崩解。
This paper focuses on the weathering decay characteristics of coal gangue in severe cold mine areas. These coal gangue are subjected to the treatments of content moisture,freeze / thaw cycles and content moisture+freeze / thaw cycles under laboratory conditions,respectively. The results show that the weathering decay rate under content moisture+freeze / thaw cycles treatment is higher than that under content moisture or freeze / thaw cycles. The hierarchical clustering method is applied to analyze the decay characteristics of the coal gaugue. The sample is almost individually clas- sified into two clusters. The result also show a significant difference in content moisture+freeze / thaw cycle groups. The existence of frost crystallization wedging brings the disintegration of coal gaugue decay rates. The results also show that the effect of moisture variation,but not freeze / thaw cycle,on rock decay is a crucial factor in coal gaugue decay. Freeze / thaw cycle,in particular,affects the coal gangue,because it causes more spalling and fracturing by frost crystal- lization. The analysis suggests that the moisture content and phase plays a key role in coal gaugue decay processes.
coal gaugue;weathering rate;freeze / thaw cycle;weathering and pedogenesis
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会