Techno-economic comparison of technologies for the concentration of a mixed leachant bleed stream

摘要

In a new hydrometallurgical process for recovery of lead from lead oxide secondaries, liquid effluence is minimized by jointly treating contaminated washing water and leachant bleed. To enable internal recycling of the leachant bleed and recover pure water, it is necessary to incorporate a concentration unit. In this paper different technologies for concentrating the mixed stream are compared. At a specified water recovery rate of 10 m~3/h, the total costs for mechanical vapour compression evaporation, freeze concentration and multiple effect evaporation are 13, 18 and 18 U$/m~3 of recovered water, respectively. The total costs decrease at increasing water recovery rates, but mechanical vapour compression evaporation remains the cheapest technology within the major part of the range studied (5-55 m~3/h water recovery).