铅锌尾矿库铊迁移转化及污染控制

Migration,Transformation and Pollution Control of Thallium in Lead-Zinc Tailings Reservoir

通过对取自云南氧化铅锌尾矿、硫化铅锌尾矿和库周土壤样品中的铊进行含量、形态和有效态分析,结合产酸试验和静态浸出试验研究铊在铅锌尾矿中的迁移转化过程和影响因素。结果表明:pH值和尾矿组成是影响铊释放的主要因素;而尾矿中有效态铊与铊总量比值是表征其释放风险的重要指标;酸性条件下铊更易溶解释放,碱性条件下尾矿中铊的活性会被抑制;pH=2时,受试硫化铅锌尾矿中铊的浸出率达32.25%;尾矿中铊由水体进入到土壤中应是造成库周土壤铊污染的主要途径,针对调查的受铊污染铅锌尾矿库周土壤,提出了“工程措施+化学沉淀+植物修复”的综合铊污染控制治理方案。

The contents,forms and available forms of thallium in tailings and soil samples from lead-zinc oxide-ore and lead-zinc sulfide-ore in Yunnan province were analyzed,the migration and transformation process of thallium in lead-zinc tailings and its influencing factors were studied by acid production test and static leaching test.The results show that pH value and tailing composition are the main factors affecting thallium release,and the ratio of available thallium to total thallium in tailings is an important index to characterize thallium release risk,when pH=2,the leaching rate of thallium in lead-zinc sulfide tailings reached 32.25%.The main way to cause thallium pollution in the soil around the reservoir is that thallium enters the soil from the water body in the tailings,a comprehensive thallium pollution control plan of"engineering measures+chemical precipitation+phytoremediation"was put forward.