闭坑煤矿水热利用的水质保障与处理模拟  

Simulation on water quality guarantee and treatment for hydrothermalutilization of closed coal mine

作　　者：周来[1,2] 张慧[1] 李松子 朱雪强 李泽[1] ZHOU Lai;ZHANG Hui;LI Songzi;ZHU Xueqiang;LI Ze(Engineering Research Center for Mine Ecological Restoration,Ministry of Education,Xuzhou 221116,China;School of Environment and Spatial Informatics,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]矿山生态修复教育部工程研究中心,徐州221116 [2]中国矿业大学环境与测绘学院,徐州221116

出　　处：《环境工程学报》2023年第7期2215-2226,共12页Chinese Journal of Environmental Engineering

基　　金：中央高校基本科研业务费专项资金中国矿业大学重大项目培育项目(2020ZDPYMS07);国家重点研发计划项目(2022YFC3702203)。

摘　　要：闭坑煤矿水热联用为煤矿区实施双碳战略的重要举措之一,其水热利用过程中最大挑战之一为集热装置的堵塞腐蚀问题。本文以常见的闭坑酸性高铁矿井水为例,采用中和-强化絮凝沉淀的处理工艺,以CaO为中和剂、聚合氯化铝(PAC)为絮凝剂、聚丙烯酰胺(PAM)为助凝剂,研究高温矿井20-50℃水温下水质调控关键参数与温度响应特征。实验表明,水温在30℃时,水中总Fe和Fe^(2+)去除效率可达最高,温度高于30℃不利于Fe^(2+)的充分氧化,温度过低不利于Fe^(3+)的水解,采用1.23 g·L^(-1)CaO+20 mg·L^(-1)PAC+3 mg·L^(-1)PAM的药剂组合可以使出水总Fe含量低于0.3 mg·L^(-1);利用分形方法分析了高温矿井水絮凝反应中絮体形态与温度变化的响应关系,温度过低或过高时,形成的絮体细密松散;30℃时絮凝反应中絮体的分形维数1.41增长到1.92,此刻分形维数增长速率最大,絮体结构大且紧实,絮体沉降速度增快,絮凝效果最佳;30℃下反应投入的CaO放热速率大于温度自然流失的速率,反应后综合温度呈上升趋势。当温度大于30℃时,絮体分形维数变化无定势,温度影响矿井水絮凝降污效率。闭坑煤矿水热联用中水质保障处理模拟为闭坑矿井水热联用的水质调控提供科学依据。Utilization of water together with thermal resource in closed coal mines is one of the important measures to implement the dual-carbon strategy in coal mines.One of the biggest challenges in the utilization of hydrogeothermal energy in closed coal mines is the blockage and corrosion of heat collectors and transfers due to water quality of mine drainage.In this study,the high-iron acid mine drainage(AMD)was taken as an example,which usually occurred in closed coal mine of China.The treatment process of neutralizationintensified flocculation and precipitation was used with CaO neutralizer,polyaluminum chloride(PAC)coagulant,and polyacrylamide(PAM)coagulant aid.The key parameters of water quality regulation at 20~50℃water temperature and temperature response characteristic in hot coal mine were studied.Experiments showed that the removal efficiencies of total Fe and Fe^(2+)in water could reach the highest values at the water temperature of 30℃,water temperature higher than 30℃was not conducive to the full oxidation of Fe^(2+),and too low temperature was not suitable for the hydrolysis of Fe^(3+).The treatment chemical package of 1.23 g·L^(-1)CaO+20 mg·L^(-1)PAC+3 mg·L^(-1)PAM could lead to the total Fe content of the effluent lower than 0.3 mg·L^(-1).The fractal method was used to analyze the synergistic relationship between floc morphology and temperature change.If the temperature was too low or too high,the floc formed was fine and loose;the floc fractal dimension increased from 1.41 to 1.92 in the flocculation reaction at 30℃,meanwhile the growth rate of the fractal dimension was the largest,and the floc structure was large and compact,the sedimentation speed of the flocs increased,and the flocculation effect was the best;at 30℃,the heat release rate of the CaO dosing in the reaction was greater than the natural loss rate of the temperature,and the comprehensive temperature after the reaction showed an upward trend.When the temperature was higher than 30℃,the change of floc fractal dimension prese

关 键 词：水质保障 地热利用 中和絮凝 酸性矿井水 闭坑煤矿 

分 类 号：X703[环境科学与工程—环境工程]