Waste water processing method during heavy metal compound production process

Abstract

The invention discloses a waste water processing method during a heavy metal compound production process, and specifically relates to a waste water processing method during a lithium ion battery cathode material producing process. According to the invention, a precipitating agent and a flocculating agent are added into heavy metal compound production waste water; the mixture is filtered and separated, such that heavy metal precipitate and a high-concentration salt solution are obtained; the high-concentration salt solution is processed through multiple-effect evaporation, condensation, and separation, such that inorganic salt crystals can be obtained; and residue waste water can be discharged into a city sewage processing system. With the method, heavy metal ions can be effectively precipitated and recovered, and ammonia nitrogen and other high-concentration salt ions can be removed and recovered. The method is simple, and the cost is low. With the method, waste water can satisfy a standard for being discharged into the city sewage processing system.

Description

technical field [0001] The invention relates to a method for treating waste water in the production process of heavy metal compounds, in particular to a method for treating heavy metal waste water produced in the process of preparing positive electrode materials for lithium ion batteries. Background technique [0002] During the preparation of the precursor of the cathode material for lithium-ion batteries, wastewater containing heavy metal ions and NH 4 + 、Na + 、K + , SO 4 2- , Cl - , NO 3 - high-concentration saline solution. Excessive salt concentration in the water body after wastewater discharge will lead to eutrophication of the water body, deterioration of water resources, salinization of the land, etc., and will also have a certain impact on human health. [0003] The above-mentioned wastewater generally needs to be discharged into urban sewage treatment plants for treatment. According to regulations, wastewater discharged into urban sewage treatment plants...

AI Technical Summary

Problems solved by technology

The disadvantage of the ion exchange method is that the one-time investment is relatively large, and the regeneration cost is high; the membrane separation method cannot completely remove the salt component; the electrolysis method is currently difficult to treat wastewater containing heavy metals and is still in the research and development stage; the ordinary evaporation process consumes a lot of energy

Most enterprises generally only use simple sedimentation tanks to treat heavy metal ions in wastewater, adjust the pH value, and then discharge them after mixing with domestic sewage. The salt concentration exceeds the standard, which will pollute surface water bodies