煤矿矿井水综合利用系统运行性能评估与优化分析

Performance evaluation and optimization analysis of comprehensive utilization system for mine wastewater in coal mine

西北地区某大型煤矿矿井水综合利用系统采用双碱法软化+陶瓷膜超滤+反渗透脱盐+纳滤分盐+碟管式反渗透膜法浓缩+MVR蒸发结晶工艺,设计处理水量为1 900 m^(2)/h,最终产水可达到工业水、农田及绿化灌溉水的回用标准要求,固体产品为质量分数98%以上的高纯度硫酸钠。对该工艺进行运行性能评估,对各个设备的运行参数及出水水质进行连续测试。测试结果表明,系统的各项性能指标基本满足设计要求,能够实现矿井水的综合利用及零排放目标。同时对系统中存在的问题,如高密度沉淀池污泥未资源化利用、超滤装置运行膜通量偏高、浓水超滤进水压力过高、纳滤装置出力及回收率偏低等进行了优化分析,并提出了改进建议。

Double alkali softening treatment+ceramic membrane ultrafiltration+RO desalination+nanofiltration salt separation+DTRO membrane concentration+MVR evaporation crystallization process is adopted in the comprehensive utilization system of mine wastewater of a large coal mine in Northwest China.Designed water quantity is 1 900 m^(2)/h,and the final product water meets the reuse standard of industrial water,farmland and greening irrigation water.The solid product is over 98%high purity sodium sulfate.Evaluation of operation performance of the process was carried out,and the operation parameters and effluent quality of each equipment were tested.The test results showed that the performance of the system basically met the design requirements and could achieve the goal of comprehensive utilization of mine wastewater and zero discharge.At the same time,the problems such as non-resource utilized sludge from high-density sedimentation tank,high membrane flux of ultrafiltration,high influent pressure of concentrated water ultrafiltration,low output and recovery rate of nanofiltration device were optimized and analyzed,and suggestions for improvement were put forward.