转炉钢渣处理酸性矿山废水的研究进展

Research process on treatment acid mine drainage by basic oxygen furnace slag

酸性矿山废水(Acidminedrainage,AMD)普遍具有pH低,Fe、Mn等离子浓度高的特点,其任意排放对环境危害很大。采用工业固体废弃物对酸性矿山废水进行中和吸附处理,具有成本低、效率高、资源综合利用率高等优点,其已成为酸性矿山废水处理的发展趋势。钢渣中含有大量的碱性物质,且吸附效果好,适于作为AMD的处理材料。对钢渣处理酸性矿山废水的研究现状进行了分析,认为钢渣适于处理废弃小型闭坑矿废水,其处理效果受钢渣成分、废水成分、工艺参数等因素的综合影响。钢渣中的含钙组分为中和AMD的主要碱性物质,特别是自由CaO的含量以及含钙组分在渣中的存在形态对处理效果影响较大。钢渣对AMD中不同离子的去除效率有所不同,其中,对Cu^(2+)、Cd^(2+)、Pb^(2+)、As^(3+)、PO_(4)^(3-)等离子的去除效率较高,对SO_(4)^(2-)的去除效率较低。另外,废水pH对处理效果的影响也较大,当pH低于钢渣表面零点电荷值时,不利于钢渣对AMD中离子的吸附。通过对钢渣进行改性处理、优化工艺参数可提高钢渣处理AMD的效果。另外,对处理AMD后的钢渣进行应用评估,对于该技术的推广应用具有重要意义。

Acid mine drainage(AMD)is generally characterized by low pH and high concentration of Fe and Mn,and its arbitrary discharge is harmful to the environment.Neutralization and adsorption treatment of acid mine drainage by industrial solid waste has the advantages of low cost,high efficiency,and high comprehensive utilization rate of resources.It has become the development trend of acid mine drainage treatment.Steel slag contains a lot of alkaline substances and has good adsorption effect,which is suitable for the development and research of AMD treatment materials.The research status of treating AMD with steel slag is analyzed.It shows that steel slag is suitable for treating small,abandoned mine drainage,and the treatment effect is comprehensively affected by steel slag compositions,AMD composition,and technological parameters.Calcium containing components are the main alkaline substances neutralizing AMD,especially the content of free CaO and its existing form in slag,which have great influence on the neutralization effect of wastewater.The removal efficiency of different ions in AMD by steel slag is different.The removal efficiency of Cu^(2+),Cd^(2+),Pb^(2+),As^(3+) and PO_(4)^(3-) is higher,while that of SO_(4)^(2-) is lower.In addition,the pH of wastewater also has a great influence on the removal of AMD.When the pH is lower than the zero charge value on the surface of steel slag,it is not conducive to the adsorption of ions in AMD.Modification treatment of steel slag-based adsorbent and optimization of process parameters can improve the effect of steel slag treatment for AMD.In addition,evaluation of steel slag after treatment of AMD are also important for the extension and application of this technology.