空气氧化碱浸含砷钴镍渣

Alkali leaching of cobalt/nickel residue containing arsenic using air

采用空气做氧化剂,在碱性体系中将砷、锌高效浸出。结果表明:在温度为80℃、碱浓度为5 mol/L、时间为12 h、液固比为5:1的条件下,砷、锌的浸出率均能够达到99%以上,2%的钴、铜被浸出,镍基本不被浸出;空气氧化浸出含砷钴镍渣的平均表观活化能为11.62k J/mol,属于扩散控制;平均反应级数为0.69;浸出渣中含铜68.24%、钴3.04%、镍0.87%,且含砷仅有0.01%,可进行铜、钴、镍的进一步回收。采用空气碱浸含砷镍钴渣,技术操作简单、成本低廉,避免剧毒砷化氢气体的产生,对含砷资源的综合利用有一定的现实意义。

Arsenic and zinc are efficiently leached in an alkaline system using air as an oxidant.The results show that the appropriate leaching conditions are listed as the follows:The alkali concentration is 5 mol/L,reaction temperature is 80 ℃,reaction time is 12 h,liquid to solid ratio is 5:1.Under the above conditions,the leaching rate of arsenic and zinc in the residue can reach more than 99% and that of cobalt and copper is below 2%.Nickel is not substantially leached.Its apparent activation energy is 11.62 kJ/mol.It can be seen that the oxidation of arsenic leaching is mainly controlled by diffusion.The average reaction order is 0.69.The leaching residue contains 68.24% Cu,3.04%Co,0.87% Ni,and only 0.01% of arsenic.It is conducive to the further recovery of copper,cobalt and nickel.The alkali leaching has simple technical operation and low cost.The technology avoids the generation of highly toxic As H3 and has practical significance for the comprehensive utilization of arsenic resources.