Method for recycling potassium chloride electrogalvanizing waste bath solution by normal-temperature evaporation method

Abstract

The invention provides a method for recycling potassium chloride electrogalvanizing waste bath solution by a normal-temperature evaporation method. The method comprises the following steps: 1, pretreating a bath solution, specifically adding 5-10ml / L of hydrogen peroxide, conducting mechanical stirring for 30 minutes, conducting heating to 60-70 DEG C, keeping the temperature for 2-4 hours, adding2-5g / L of activated carbon powder, conducting mechanical stirring for 30 minutes, conducting standing for 4-8 hours, and conducting filtering to a clear state; and 2, pumping the pretreated bath solution into natural evaporation equipment by using a pump, and carrying out evaporation purification, wherein the natural evaporation equipment is formed by connecting platforms in parallel and in series, the platforms are formed by paving a plurality of soft PVC plates on flat ground or a tray formed by iron plates, pipelines and pumps are used for connection, and the natural evaporation equipmentis similar to a seawater salt drying device. According to the method for recycling the potassium chloride electrogalvanizing waste tank liquid through the normal-temperature evaporation method, the generated potassium chloride electrogalvanizing waste liquid is completely recycled, environmental pollution is avoided, investment is small, and the operation cost is low.

Description

technical field [0001] The invention relates to the field of evaporation recovery of waste bath liquid, in particular to a method for recovering and utilizing waste bath liquid of potassium chloride electroplating galvanizing by normal temperature evaporation. Background technique [0002] Potassium chloride electro-galvanizing is the largest type of electro-galvanizing, the bath contains 200-250 g / L potassium chloride, 35-60 g / L zinc chloride, 20-35 g / L boric acid, and appropriate amount of organic additives . There are 200,000 to 400,000 cubic meters of potassium chloride electroplating baths being produced nationwide. Because the temperature of the potassium chloride galvanizing process is 20-30 ° C, the water evaporates very little, and potassium chloride, boric acid, zinc chloride, and liquid additives must be continuously added during the production process, resulting in the continuous increase in the volume of the bath solution. (According to 300 working days) there...

AI Technical Summary

Problems solved by technology

Because the temperature of the potassium chloride galvanizing process is 20-30 ° C, the water evaporates very little, and potassium chloride, boric acid, zinc chloride, and liquid additives must be continuously added during the production process, resulting in the continuous increase in the volume of the bath solution. (According to 300 working days) there are 400,000 to 1,000,000 square meters of extra bath liquid, and so much bath liquid is finally discharged into the wastewater treatment station, where the lye is used to neutralize the precipitated zinc ions, and the biochemical system treats organic matter , reduce COD, and separate zinc-containing sludge and wastewater through a plate-and-frame filter press. The zinc-containing sludge is handed over to a qualified sludge disposal company for treatment. The wastewater is adjusted to meet the PH value and discharged into the natural water body, and a large amount of salt enters, causing high salinity