Abstract: In Guixi Smelter of Jiangxi Copper Company Limited，in order to solve the adverse effects of solid suspended solids in the production return water of the beneficiation workshop on production and equipment，based on the precision filtration technology，the purification test of the return water is carried out.Based on the analysis of the basic characteristics of suspended solids in return water，four kinds of fil⁃ tration accuracy of 1，3，5 and 10 μm are compared in parallel. The attenuation law of filtration flux， backwash regeneration ability and visual clarity of filtered water are emphatically investigated.The experi⁃ mental results show that the flux changes of 1，3，5 μm filter cartridge show good regularity. After back⁃ washing，the flux is restored to be stable，and the filtered water is clear and bright. Considering the factors of filtration efficiency and long-term operation economy，3 μm precision is the optimal pore size for the treatment of the slag selection return water，which can provide engineering reference for the short process purification of similar low concentration slurry return water.

Key words: slag selection, return water purification, suspended solids, precision filtration, flux re? covery