回转窑焙烧铅锌冶炼废水污泥重金属物质流向研究

Study on Current Direction of Heavy Metal Material in the Waste Water and Sludge from Lead and Zinc Smelting by Rotary Kiln Roasting

采用回转窑高温焙烧铅锌废水处理污泥,研究回转窑焙烧过程烟气重金属物质流向的基础理论,可以评价该工艺重金属污染控制的适用性。通过XRF、ICP-OES、ICP-MS等手段检测分析废水处理污泥焙烧前后固体物料及烟气中重金属含量。结果表明:高温焙烧使得大部分重金属挥发为气态,随烟尘沉降而被捕集;各重金属的回收效率分别为Zn 89.1%、Pb 76.7%和Cd 47.3%。水淬渣中重金属含量显著降低,Zn、Pb、As、Cd含量分别降低至0.46%、0.016%、0.05%和0.05%。重金属流向分析表明,除尘后3.9%Zn、19.4%Pb、33.2%Cd、63.2%As及100%Hg进入烟气中。采用回转窑处理铅锌废水污泥不仅可资源回收有价金属铅、锌、镉,还降低了炉渣重金属含量,为铅锌冶炼行业重金属污染控制与危险废物资源化提供参考借鉴和指导意义。

The rotary kiln is adopted for treatment of sludge by high temperature roasting of lead and zinc waste water,the basic theory of current direction of heavy metal material in the fume in the process of rotary kiln roasting is studied,which can evaluate the applicability of contamination control of heavy metal. The solid material and heavy metal content in the fume before and after roasting is detected by XRF,ICP-OES,ICP-MS and so on. The results show： most heavy metals are volatilized by high temperature roasting and are collected along with fume sedimentation; the recovery rates of each heavy metal separately is： Zn 89. 1%,Pb 76. 7% and Cd 47. 3%. The heavy metal content in the water-quenched slag is decreased obviously,the content of Zn,Pb,As,Cd are decreased to 0. 46%,0. 016%,0. 05% and 0. 05%. The current direction analysis of heavy metal show,there is 3. 9% Zn,19. 4% Pb,33. 2% Cd,63. 2% As and100% Hg entered into the fume after dedusting. The valuable metal-lead,zinc,cadmium not only can be recycled resourceful,and the heavy metal content of furnace slag can be reduced by adoption of rotary kiln for treatment of lead and zinc waste water and sludge,which supply the reference,consulting and guiding significance to heavy metal pollution controlling and hazardous wastes recycling in the lead and zinc smelting industry.