Removal of Ni(II) from strongly acidic wastewater by chelating precipitation and recovery of NiO from the precipitates.
Removal of Ni(II) from strongly acidic wastewater by chelating precipitation and recovery of NiO from the precipitates.
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DOI：
10.1016/j.jes.2020.12.014
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发表时间：
2021-06
影响因子：
6.9
通讯作者：
Xin Yang;Xianjia Peng;Linghao Kong;Xingyun Hu
中科院分区：
文献类型：
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作者：
Xin Yang;Xianjia Peng;Linghao Kong;Xingyun Hu
有色金属冶炼工业中产生的强酸性废水通常含有高浓度的Ni（II），这是一种有价值的金属。本研究评价了使用二甲基二硫代氨基甲酸钠（DDTC）作为沉淀剂从强酸性废水中沉淀Ni（II）的效果。考察了各种因素对沉淀过程的影响，并对沉淀机理进行了探讨。最后，沉淀物中的镍在火法冶金方法之后被回收。结果表明，在优化条件下（DDTC：Ni（II）摩尔比= 4：1;温度= 25 °C），10 min后Ni（II）去除率达到99.3%。在强酸性废水中，DDTC的二硫代氨基甲酸酯基团可与Ni（II）反应生成DDTC单键Ni沉淀。进一步的回收实验表明，DDTC单键镍沉淀经煅烧可得到高纯NiO，镍的回收率可达98.2%。煅烧过程中释放的气体由NO2、CS2、H2O、CO2和SO2组成。这些结果为从强酸性废水中有效回收Ni（II）提供了依据。
Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(II), which is a valuable metal. In this study, the precipitation of Ni(II) from strongly acidic wastewater using sodium dimethyldithiocarbamate (DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions (DDTC:Ni(II) molar ratio = 4:1; temperature = 25 °C), the Ni(II) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(II) to form DDTCsingle bondNi precipitates. Further recovery experiments revealed that high-purity NiO can be obtained by the calcination of DDTCsingle bondNi precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO2, CS2, H2O, CO2, and SO2. These results provide a basis for an effective Ni(II) recovery method from strongly acidic wastewater.