氨法处理高炉瓦斯灰制取等级氧化锌研究

以氨-碳酸氢铵混合液为浸出剂浸出高炉瓦斯灰中的有价金属锌,经净化、蒸氨、煅烧得到等级氧化锌,对相关工艺参数进行优化选择。结果表明,最佳浸出条件为:[氨水]/[NH4HCO3]=2、液固比为4、总氨浓度为5mol·L-1,浸出时间为3h,此条件下锌浸出率为82.55%;最佳净化条件为:锌粉用量为1.5g·L-1、净化时间为2.5h,此条件下铅的脱除率为97.70%;最佳蒸氨条件为90℃下蒸氨至终点溶液pH值为6~7,此条件下蒸氨后锌的沉淀率可达99.95%。沉淀物在500℃下煅烧1h,得到纯度为96.03%的氧化锌粉末,达到了HG/T2527—94的一级标准。

Preparation of grade zinc oxide from blast furnace dust by using ammonia process

Given the valuable metal zinc in blast furnace dust ,the grade zinc oxide was prepared from blast furnace dust by the process of leaching with ammonia-ammonium ,purification with zinc pow-der ,ammonia still process and calcination .The results show that the optimal conditions of leaching are the ratio of the concentration of ammonia to that of ammonium being 2 ,the ratio of liquid to solid being 4 ,the total ammonia concentration being 5 mol· L -1 ,and the leaching time being 3 hours ,un-der which the extraction rate of zinc is 82 .55% ;the optimal conditions of purification are that the con-sumption of zinc powder is 1 .5 g · L -1 ,the purification time is 2 .5 hours ,under which the desorption rate of Pb is 97 .70% ;and the optimal conditions of ammonia still process are that the temperature is 90 ℃ and pH value of pH is 6 to 7 ,under w hich the precipitation rate of zinc is 99 .95% .Calcined at 500 ℃ for 1 hour ,the content of zinc oxide powder is 96 .03% ,which complies with the primary standard of HG/T2527-94 .