铅阳极泥剪切射流曝气强化碱浸脱砷工艺研究  

Enhanced alkaline leaching of arsenic in lead anode slime using shearing jet aeration reactor

作　　者：闵小波[1,2] 周波生 柴立元[1,2] 梁彦杰[1,2] 柯勇[1] 赵宗文[1] 沈忱[1] 

机构地区：[1]中南大学冶金与环境学院,长沙410083 [2]国家重金属污染防治工程技术研究中心,长沙410083

出　　处：《有色金属科学与工程》2015年第4期1-5,75,共6页Nonferrous Metals Science and Engineering

基　　金：国家自然科学基金资助项目(51474247);国家公益性行业科研专项(201509050);湖南省科技重大专项(2014FJ1011)

摘　　要：采用剪切射流曝气反应器对铅阳极泥碱浸脱砷过程进行强化,考察了液固比、氢氧化钠浓度、时间及温度等因素对阳极泥中砷、铅、锑、铋浸出率的影响,通过正交实验优选出最佳浸出工艺条件,即:氢氧化钠浓度1 mol/L、浸出液体积/固体质量(液固比)为6 m L/g、温度70℃、时间1 h.在此最佳工艺条件下,砷浸出率高达95%以上,而铅、锑浸出率分别维持在2%、1%以下,铋基本不被浸出.针对高砷浸出液采用石灰沉砷,沉砷率可达85%以上.沉砷后上清液补充一定的氢氧化钠可返回浸出工序,回用效果理想,浸砷率高达94%以上.与常规碱浸脱砷相比,采用剪切射流曝气碱浸脱砷可以有效地降低Na OH用量,缩短浸出时间及提高砷与有价金属的分离率.由此可见,剪切射流曝气反应器可以应用于含砷物料的预处理,实现砷的高效浸出.In this study, alkaline leaching enhanced by shearing jet aeration reactor was employed to remove arsenic from lead anode sline. The effects of various parameters, such as liquid/solid ratio, concentrations of sodium hydroxide solution, leaching time and temperature, on leaching ratios of different metals were investi- gated. On this basis, the optimal conditions was obtained through orthogonal experiment, namely, 1.0 mgl/L NaOH, a liquid/solid ratio of 6：1, leaching at 70 ~C for 1 h. Under this optimal condition, the leaching rate of As reached up to 95.0 %, and that of Pb and Sb was less than 2.0 % and 1.0 %, respectively, while Bi was hardly dissolved in alkaline solution. In addition, arsenic-containing leachate could be treated with lime and removal rate of As in leachate exceeding 85 %. Then, the filtrate from lime precipitation was recycled and reused in leaching process. Also, a satisfying result could be obtained with more than 95 % of As leaching rate after the filtrate was recycled. Compared with the conventional alkaline leaching for As removal, this process could decrease the dosage of sodium hydroxide, shorten the leaching time, and efficiently improve the separation rate of arsenic and other valuable metals. It can be concluded that the shearing jet aeration reactor can beapplied to the pretreatment of arsenic-containing materials and obtain a high leaching rate of arsenic.

关 键 词：铅阳极泥 剪切 射流曝气 碱浸 脱砷 

分 类 号：TF812[冶金工程—有色金属冶金] TF114.1