摘要
矿山排土场生态修复是煤矿露天开采面临的重大环境问题,是制约建设绿色露天煤矿的重要因素。土壤重构是排土场生态修复的重要步骤,以新疆为代表的西北煤炭基地,水资源短缺,盐碱化突出,土壤水盐运移是决定土壤重构是否成功的关键指标。目前研究集中在表层土壤重构改善土壤养分促进植物生长,针对保水控盐的功能化土壤重构的研究甚少,对不同土壤重构方式下的水盐运移机制尚不明晰。研究立足新疆煤炭资源禀赋特征,从煤炭循环经济的角度出发,采用能源化工副产物煤气化渣(CGS)作为重构材料,通过毛细水上升-蒸发试验,分析CGS重构后水盐垂向运移和水分供给能力,通过Van Genuchten模型拟合土壤水分特征曲线,分析CGS重构后土壤持水能力,研究CGS作为含水层重构材料的可行性。采用煤矿开采伴生岩石矿物红泥岩作为重构材料,通过土柱入渗蒸发试验,分析红泥岩重构后不同土壤深度的水盐变化情况,研究泥岩作为隔水层重构材料的可行性。结果表明,CGS重构改善土壤质地,优化孔隙结构,促进了土壤水盐运移,毛细作用增强,促进了下层水分向上供给,同时也增加了盐分表聚,重构改变土水特征曲线参数,增加了饱和含水量θ_(s),降低了参数a和n,改善了土壤持水性能。CGS添加量越高,细渣质量分数越大,效果越明显。CGS作为重构含水层材料具有可行性。红泥岩黏粒和次生矿物含量高,孔隙结构丰富,物理吸附性良好,重构后0~24 cm深度下土壤含水率高于对照组,蒸发后的盐分在20~24 cm达最高值,红泥岩有效阻隔了盐分上移。红泥岩作为重构隔水层材料具有可行性。研究以期探索出一条适合西部煤炭基地排土场土壤重构模式。
The ecological restoration of mine dump is a major environmental problem faced by open-pit mining,and it is an important factor restricting the construction of green open-pit coal mine.Soil reconstruction is an important step in the ecological restoration of dumps.The northwest coal base,represented by Xinjiang,is characterized by water scarcity and salinization.Soil water and salt migration is a key indicator to determine the success of soil reconstruction.At present,the research focuses on the surface soil reconstruction to improve soil nutrients and promote plant growth.There are few studies on the functional soil reconstruction of water and salt control,and the mechanism of water and salt transportation under different soil reconstruction methods is still unclear.Based on the characteristics of coal resource endowment in Xinjiang,from the perspective of coal circular economy,this study used coal gasification slag(CGS),a by-product of energy and chemical industry,as a reconstruction material.Through a capillary water rising-evaporation experiment,the vertical migration of water and salt and water supply capacity after CGS reconstruction were analyzed.The Van Genuchten model was used to fit the soil water characteristic curve,analyzed the soil water holding capacity after CGS reconstruction,and studied the feasibility of CGS as an aquifer reconstruction material.The red mudstone associated with coal mining was used as the reconstruction material.Through the soil column infiltration evaporation experiment,the water and salt changes at different soil depths after the reconstruction of red mudstone were analyzed,and the feasibility of mudstone as the reconstruction material of aquiclude was studied.The results showed that the CGS reconstruction improved soil texture,optimized pore structure,promoted soil water and salt transport,enhanced capillary action,promoted the upward supply of water in the lower layer,and also increased salt surface accumulation.The reconstruction changed the parameters of soil water charac
作者
张凯
李晓楠
暴凯凯
姜凯升
王潇芫
谭栩荧
ZHANG Kai;LI Xiaonan;BAO Kaikai;JIANG Kaisheng;WANG Xiaoyuan;TAN Xuying(School of Chemical&Environmental Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Guoneng Xinjiang Hongshaquan Energy Co.,Ltd.,Changji Prefecture 831100,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2024年第3期1556-1569,共14页
Journal of China Coal Society
基金
国家重点研发计划资助项目(2022YFF1303304)
国家自然科学基金资助项目(42177037)
煤基大宗固废生态综合利用技术研发与示范基金资助项目(GJNY-22-71)。
关键词
土壤重构
水盐运移
煤气化渣
红泥岩
毛细水上升
soil reconstruction
water and salt transport
coal gasification slag
red mudstone
capillary water rising
