The Case Study Of Safe Treatment Projects Of Arsenic Residue Of A Mining Area In Chenzhou Hunan

The population of Xiangjiang River is concentrated, economic is developed, urbanization is the highest level of development in Hunan Province. The total area of the basin accounts for 40.3% of the province, but also bear more than 60% of the province’s pollution, heavy industry this basin have started very early, has a certain history, since a very long time, because the industry is unreasonable, regulators pattern as a result of imperfect heavy metal pollution in the region. Located in southern Hunan Chenzhou City, known as the rural non-ferrous metals, non-ferrous metals and arsenic contamination is one of the most common smelting process heavy metal pollution in many parts of the basin are subject to different levels of heavy metals arsenic, and further expansion trend, heavy metal pollution on human health more harm. In addition, frequent incidents of arsenic contamination in the community caused a very bad influence. Arsenic pollution control, it is necessary to control arsenic waste. Arsenic waste in complex chemical composition, in which the highest arsenic content, but also contains copper, mercury, tin, zinc and other elements, if such materials long buried in the ground, the soil will cause pollution and affect the quality of groundwater and thus on human health hazard. Thus, arsenic waste management has a very important significance.In this paper, the arsenic-containin wastes residue(arsenic residue) of Chenzhou mines was employed as the research object, through checking pretreatment technology and comparing schemes, the stabilization/solidification pretreatment technology is put forward. The goal of low cost and good curing effect is achieved by using an optimum cement/ arsenic residue ratio and water/cement ratio.The optimum process conditions are detemined as follow: arsenic residue: cement: stabilizer =100: 20: 2; water/cement ratio=1.5. Arsenic residue and cement are milled in a cement mortar mixing machine for 20 sec, and then add 6.7% aqueous solution of sodium sulfide in 10~20 sec, and then milled for 360±5 sec. The mixing mortar will be landfilled in pumping way and solidificated in the landfill site. The SEM analysis results show that the leaching concentrations of As is 3~4mg/L. Its properties far below the standards of GB5085.3-2007.According to the conclusion of the experiment, the project can basicly eliminate the contamination on water and soil near by waste residue. And As、Pb、Cd、Zn、Cu would respectively cut down 0.73t/a、0.30 t/a、0.070 t/a、0.52 t/a、0.76 t/a after the implementation of the project. This calculation provides a basis for the improvement of the ecological environment and water quality of Xiangjiang river basin.