Institute for Sustainability and Innovation, College of Engineering and Science, Victoria University, P.O. Box 14428, Melbourne, Vic 8001, Australia E-mail:
CSIRO, Process Science and Engineering/CSIRO Minerals Down Under National Flagship, Australia, P.O. Box 7229 Karawara, WA 6152, Australia.
Water Sci Technol. 2014;69(4):868-75. doi: 10.2166/wst.2013.788.
This paper describes for the first time the use of direct contact membrane distillation (DCMD) for acid and water recovery from a real leach solution generated by a hydrometallurgical plant. The leach solutions considered contained H2SO4 or HCl. In all tests the temperature of the feed solution was kept at 60 °C. The test work showed that fluxes were within the range of 18-33 kg/m(2)/h and 15-35 kg/m(2)/h for the H2SO4 and HCl systems, respectively. In the H2SO4 leach system, the final concentration of free acid in the sample solution increased on the concentrate side of the DCMD system from 1.04 M up to 4.60 M. The sulfate separation efficiency was over 99.9% and overall water recovery exceeded 80%. In the HCl leach system, HCl vapour passed through the membrane from the feed side to the permeate. The concentration of HCl captured in the permeate was about 1.10 M leaving behind only 0.41 M in the feed from the initial concentration of 2.13 M. In all the experiments, salt rejection was >99.9%. DCMD is clearly viable for high recovery of high quality water and concentrated H2SO4 from spent sulfuric acid leach solution where solvent extraction could then be applied to recover the sulfuric acid and metals. While HCl can be recovered for reuse using only DCMD.
本文首次描述了直接接触膜蒸馏（DCMD）在从湿法冶金厂产生的实际浸出液中回收酸和水的应用。所考虑的浸出液含有 H2SO4 或 HCl。在所有测试中，进料溶液的温度保持在 60°C。试验结果表明，对于 H2SO4 和 HCl 体系，通量分别在 18-33 kg/m(2)/h 和 15-35 kg/m(2)/h 的范围内。在 H2SO4 浸出系统中，DCMD 系统浓缩侧样品溶液中游离酸的最终浓度从 1.04 M 增加到 4.60 M。硫酸盐分离效率超过 99.9%，总水回收率超过 80%。在 HCl 浸出系统中，HCl 蒸气从进料侧透过膜进入渗透侧。在渗透侧捕获的 HCl 浓度约为 1.10 M，而进料中仅留下 0.41 M，初始浓度为 2.13 M。在所有实验中，盐的截留率均>99.9%。DCMD 显然适用于从废硫酸浸出液中高回收高质量水和浓 H2SO4，然后可以应用溶剂萃取回收硫酸和金属。而仅使用 DCMD 即可回收 HCl 以重复使用。
