Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education, School of Metallurgy, Northeastern University, Shenyang 110819, P. R. China.
School of Resource and Environmental Science, Wuhan University, Wuhan 430072, P.R. China.
Proc Natl Acad Sci U S A. 2022 Aug 2;119(31):e2202884119. doi: 10.1073/pnas.2202884119. Epub 2022 Jul 25.
Traditional sulfide metallurgy produces harmful sulfur dioxide and is energy intensive. To this end, we develop an anode electrolysis approach in molten salt by which sulfide is electrochemically split into sulfur gas at a graphite inert anode while releasing metal ions that diffuse toward and are deposited at the cathode. The anodic splitting dictates the "sulfide-to-metal ion and sulfur gas" conversion that makes the reaction recur continuously. Using this approach, CuS is converted to sulfur gas and Cu in molten LiCl-KCl at 500 °C with a current efficiency of 99% and energy consumption of 0.420 kWh/kg (only considering the electricity for electrolysis). Besides CuS, the anode electrolysis can extract Cu from Cu matte that is an intermediate product from the traditional sulfide smelting process. More broadly, Fe, Ni, Pb, and Sb are extracted from FeS, CuFeS, NiS, PbS, and SbS, providing a general electrochemical method for sulfide metallurgy.
传统的硫化物冶金会产生有害的二氧化硫，且能源密集。为此，我们开发了一种在熔盐中的阳极电解方法，通过该方法，硫化物在石墨惰性阳极上电化学分裂为硫气体，同时释放出金属离子，这些离子扩散到阴极并沉积在阴极上。阳极的分裂决定了“硫化物到金属离子和硫气体”的转化，使反应能够持续不断地进行。使用这种方法，在 500°C 的 LiCl-KCl 熔盐中，CuS 可以转化为硫气体和 Cu，电流效率为 99%，能耗为 0.420 kWh/kg（仅考虑电解所需的电力）。除了 CuS，阳极电解还可以从传统硫化物熔炼过程的中间产物 Cu matte 中提取 Cu。更广泛地说，FeS、CuFeS、NiS、PbS 和 SbS 中的 Fe、Ni、Pb 和 Sb 也可以被提取出来，为硫化物冶金提供了一种通用的电化学方法。
