Supernatant wastewater comprehensive recovery and purification system and process after nickel carbonate preparation by nickel electrolysis liquid purification system

Abstract

The invention provides a supernatant wastewater comprehensive recovery and purification system and process after nickel carbonate preparation by a nickel electrolysis liquid purification system. The supernatant wastewater comprehensive recovery and purification system comprises a dechlorination reaction tank, a cooler, a pH regulating tank, a conveying pump, a cartridge filter, a high pressure pump, a circulating pump and a nanofiltration unit, which are connected in sequence, wherein a brine outlet of the nanofiltration unit is connected with a brine storage tank, and a dense phase water outlet is connected with a dense phase water storage tank of the nanofiltration unit. According to the invention, sodium chloride, sodium sulfate and heavy metal ions in supernatant wastewater after the nickel carbonate preparation by the nickel electrolysis liquid purification system are effectively separated, and the dense phase water of the separated sodium chloride, sodium sulfate and heavy metal ions are comprehensively recovered to solve the problem that liquid waste is drained to pollute the environment.

Description

technical field [0001] The invention belongs to the technical field of nickel electrolysis, and relates to a system and process for comprehensive recovery and purification of supernatant waste water after the nickel electrolytic cleansing system prepares nickel carbonate, which can separate heavy metals such as sodium sulfate and nickel from the above waste water from sodium chloride, And realize comprehensive recycling. Background technique [0002] Sulfide soluble anode nickel electrolysis process is the mainstream process of nickel electrolytic refining in my country and even in the world, but in order to balance the liquid volume and sodium ions of the electrolytic system, it is necessary to extract a part of the electrolyte from the electrolytic closed circuit system, add soda ash to precipitate to produce nickel carbonate, and precipitate The supernatant of the final solution contains a large amount of sodium chloride, a small amount of heavy metal ions such as sodium s...

AI Technical Summary

Problems solved by technology

At present, this kind of wastewater is mixed with other heavy metal-containing wastewater and treated by lime neutralization, but because the treatment process does not have the ability to remove salt, the content of sodium salt in the treated wastewater is too high, which limits recycling. Drainage will pollute the environment, especially the groundwater, which is especially obvious in the arid areas of Northwest China

Excessive groundwater salinity restricts the use of groundwater and increases its cost. Irrigation can also lead to soil salinization

Images