煤炭在未来依然是中国能源结构的重要组成部分,煤炭开采过程中产生含高浓度硫酸盐的煤矿酸性废水(ACMD)是制约其实现高质量绿色可持续发展的关键。ACMD是SO2-4的一个重要工业污染来源,其主要是含硫矿暴露后的氧化作用产生。通过回顾ACMD的形成机理和危害,分析了可用于源头预防和后续处理的技术,秉持“预防胜于治理”的原则,全面分析了抑菌剂、氧气隔绝和表面钝化等预防硫酸盐产生的技术特点,后续处理阶段目前采用较多的技术包括化学沉淀、吸附、离子交换与膜技术的主动修复技术和以生物处理与人工湿地为主的被动修复技术。主动修复技术存在二次污染的风险和成本较高等问题,被动修复技术的处理时间和系统稳定性限制其广泛应用;鉴于硫酸在化学和冶金工业中市场可观,从ACMD回收硫酸的资源化前景潜力巨大,目前关于从ACMD中回收硫酸的潜在技术包括精馏、扩散渗析、电渗析、溶剂萃取和结晶等,评估了每种工艺应用于ACMD中的技术和经济可行性;最后着重强调了关于ACMD中硫酸盐防治和资源化技术的未来发展前景,其中包括深入研究预防技术,降低处理成本,开发新型稳定的处理和回收工艺,为煤炭行业的污染控制与废弃物资源化提供新的控制策略和更广泛的研究思路。

Coal will still be an important part of the China′s energy structure in the future. The acid coal mine drainage (ACMD)containing high concentrations of sulfates produced during the coal mining process is the key to restricting its realization of high-quality, greenand sustainable development. ACMD is an important industrial pollution source of SO2-4 , primarily generated by the oxidation of sulfur containing ores after exposure. The formation mechanism and hazards of ACMD were reviewed and the technologies that could be used forsource prevention and subsequent treatment were analyzed. Adhering to the principle of " prevention is better than cure" , the comprehensive analysis was conducted on the technical characteristics of preventing sulfate production such as biocides, oxygen isolation and surfacepassivation. Many technologies are currently used in the subsequent treatment stage, including active remediation technologies suchas chemical precipitation, adsorption, ion exchange and membrane technology, and passive remediation technologies based on biologicaltreatment and constructed wetlands. Active remediation technology has problems such as the risk of secondary pollution and higher costs,while the widespread application of passive remediation technology is restricted due to the processing time and system stability. Due tothe considerable market of sulfuric acid in the chemical and metallurgical industries, recycling sulfuric acid from ACMD is a good resourceprospect. Current potential technologies for recovering sulfuric acid from ACMD include distillation, diffusion dialysis, electrodialysis, solvent extraction and crystallization. The technical and economic feasibility of each process for application in ACMD was evaluated. Finally,the future development prospects of sulfate prevention and resource recovery technologies in ACMD were emphasized, including conductingin-depth research on prevention technologies, reducing treatment costs, and developing new and stable treatment and recovery processes,providing new control strategies and broader research ideas for pollution control and waste recycling in the coal industry.

0 引言

1 煤矿酸性废水的形成与危害

   1.1 煤矿酸性废水的形成

   1.2 煤矿酸性废水的危害

2 煤矿酸性废水中硫酸盐防治技术

   2.1 煤矿酸性废水中硫酸盐的源头预防

   2.2 煤矿酸性废水中硫酸盐的处理技术

3 煤矿酸性废水中硫酸盐的回收

   3.1 精馏

   3.2 扩散渗析、电渗析

   3.3 溶剂萃取

   3.4 结晶

   3.5 回收技术对比

4 结语与展望