Abstract This study focused on the performance of an UF–NF–RO integrated system treating a gold mining effluent from the pressure-oxidation stage in order to concentrate metals, and recover acid and water. Aspects such as the most suitable cross-flow velocity, cleaning procedure, and water recovery fraction were evaluated. For cross-flow velocities, a threshold value of 1.5 × 10−2 m/s was found for NF and RO stages. Besides, the system had its best performance while operating at recovery fractions of 90%, 40–50%, and 50% for UF, NF, and RO, respectively. Concentration factors of 2.0 and 2.7 were found in metals from the NF retentate and sulfuric acid from the RO retentate respectively. For cleaning purposes, hydrochloric and oxalic acid demonstrated the best cost-benefit. A long-term operation inside the mining company was assessed and the results confirmed that NF and RO association allowed for the recovery of a purified acid stream, which may be reused in the ore processing; the production of a metal enriched stream, that can be transferred to a subsequent metal recovery stage; and the generation of high quality reuse water. The total cost of the proposed route was US$ 1.137/m3 of effluent, including UF and NF concentrate neutralisation.

中文翻译：

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用于金矿废水处理的综合 UF-NF-RO 路线：从实验室规模到中试规模

摘要 本研究的重点是 UF-NF-RO 集成系统处理来自压力氧化阶段的金矿废水以浓缩金属并回收酸和水的性能。对最合适的错流速度、清洁程序和水回收率等方面进行了评估。对于错流速度，NF 和 RO 阶段的阈值为 1.5 × 10−2 m/s。此外，该系统在 UF、NF 和 RO 的回收率分别为 90%、40-50% 和 50% 时具有最佳性能。在来自 NF 截留物的金属和来自 RO 截留物的硫酸中发现的浓度因子分别为 2.0 和 2.7。出于清洁目的，盐酸和草酸显示出最佳的成本效益。对矿业公司内部的长期运营进行了评估，结果证实 NF 和 RO 联合允许回收纯化的酸流，可在矿石加工中重复使用；生产富含金属的流，可以转移到后续的金属回收阶段；并产生高质量的回用水。拟议路线的总成本为 1.137 美元/立方米的污水，包括 UF 和 NF 浓缩物中和。