Leaching behavior of secondary zinc oxide dusts in ammonia solutions
Leaching of secondary zinc oxide dusts is an important process in recovery of zinc from solid wastes to produce zinc based products. Compared with acid leaching, ammonia leaching has many advantages and has been accepted as a more promising method for zinc leaching. Therefore, research on the leaching behavior of secondary zinc oxide dusts in ammonia solutions is of great importance for optimization and better controllability of the process. On the basis of study on dissolution of pure ZnO in ammonia solutions, the leaching behaviors of two secondary zinc oxide samples in ammonia leaching systems were investigated in this paper. The results indicated that, different samples had different leaching property. In ammonia solutions of the same conditions, pure ZnO has higher dissolution capacity than the two secondary zinc oxide samples, and difference also appeared between the two different secondary zinc oxide samples in zinc dissolution capacity. At the conditions of L/S = 5:1, NH3 total: CO3 2- =4:1 ( mol/mol) , the optimum leaching conditions were 20 min, 400 r/min for pure ZnO, 30 min, 400 r/min for sample A and 60 min, 500 r/min for sample B. Under their respective optimum leaching conditions, NH3 total: Zn2 + total ratios in solutions were 8. 1:1, 11.2:1, and 20 :1 for pure ZnO, sample A and sample B respectively, indicating different leaching capacity of the same amount of NH3 for different samples. To obtain the same leaching ratio of zinc, sample B required higher leaching reagents concentration than sample A. The main cause for these differences in leaching behavior lies in the species and contents of impurities present in the samples, higher contents of Pb, Fe, Cd are responsible for lower zinc leaching ratio and more ammonia consumption for sample B.
zinc oxide secondary zinc oxide ammonia leaching zinc leaching
Yongbin Yang Wenjuan Wang Qian Li Tao Jiang Xianju Shi
School of Minerals Processing and Bioengineering, Central South University Room 932,Lushan Road (South), 410083, Changsha, China
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
803-807
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）