钢铁冶金烧结除尘灰中银、铜、锌的浸提回收工艺研究  

Recovery of Silver,Copper and Zinc in Sintering Filtrated Dust from Iron and Steel Metallurgical Process

作　　者：吴滨[1] 张梅[1] 付志刚[1] 杨水莲[1] 王威燕[1] 杨运泉[1] 

机构地区：[1]湘潭大学化工学院,湖南湘潭411105

出　　处：《稀有金属》2015年第12期1108-1114,共7页Chinese Journal of Rare Metals

基　　金：湖南省自然科学基金项目(14JJ5027);国家环境保护部水体污染控制与治理科技重大专项(2010ZX07212-008)资助

摘　　要：采用银含量在250~400g·t^(-1)、含铜和含锌量均在1.0%(质量分数)以下的钢铁冶金烧结除尘灰为原料,以氨水为络合剂,研究了氨络合浸取回收烧结灰中贵金属银和有色金属铜、锌等元素的方法。利用银与甲醛的银镜反应原理、活泼金属的梯级还原置换原理、碳酸钠与含锌液反应生成碳酸锌沉淀及其煅烧分解反应原理,研究了从银、铜和锌的混合氨络合物中分步分离回收各金属元素并制备其相应单质或化合物产品的工艺路线及工艺条件。结果表明,在浸取过程中较适宜的工艺条件为:氨水浸取时间20min,氨水用量4.12mol·kg^(-1)烧结灰。在此条件下,各烧结灰样中银的浸出率均可达到70%以上。经分步分离回收实验所得的银产物中Ag元素的含量为91.20%,铜产物中Cu元素的含量为86.40%,氧化锌产物中ZnO的含量为98.70%。烧结除尘灰中银、铜和锌元素的总回收率分别为71.20%,60.40%和56.71%。该工艺具有操作简便、回收效率较高、生产成本低等优点,是一条适合于规模化生产的钢铁冶金烧结除尘灰中银及其他有色金属元素回收与综合利用新工艺。Using sintering filtrated dust from iron and steel metallurgical process as raw material of which the silver content was 250 -400 g t-1, and the copper and zinc contents were both less than 1.0% （mass fraction）, and with ammonia as chelating agent, a new method for recovering precious metal silver, nonferrous metals such as copper and zinc was studied. According to the silver mirror reaction principle for silver and formaldehyde, the stepped replacing reduction principle for active metals, sodium carbonate and zinc liquid reaction to produce zinc carbonate sediments and its decomposition reaction principle of calcination, the optimized conditions for the leaching and the separation of silver, copper and zinc in the dust and in their mixed ammine chelated solution were investigated, re- spectively. The preparation methods for the elemental or compound products of silver, copper and zinc recovered from the dust were developed. The experimental results showed that the appropriate conditions for the leaching process were leaching time of 20 min and the ammonia dosage of 4.12 mol kg-1 sintering filtrated dust. Under the conditions, all of the leaching rates of silver from each sintering filtrated dust could reach more than 70%. With the fractional and separation recycling experiments, the Ag element content of silver products was 91.20%, the Cu element content of copper products was 86.40%, and the Zn element content of ZnO products was 98.70%. The total recovery rates of silver, copper and zinc in the dust were 71.20% , 60.40% and 56.70% , respectively. The new developed process had advantages of simplified operation, higher recovery efficiency and lower production cost, which was suitable for the large-scaled recovering and comprehensive utilization of silver and other non-ferrous metallic elements in the sintering dust from iron and steel metallurgical enterprise.

关 键 词：烧结除尘灰 氨络合浸取 银镜反应 还原置换 回收 

分 类 号：TQ131.13[化学工程—无机化工]