Method for recovering copper sulfate in acidic copper sulfate waste liquid

Abstract

The invention relates to the field of waste liquid treatment, and particularly discloses a method for recovering copper sulfate in acidic copper sulfate waste liquid. The method comprises the following steps: S1, collecting the acidic copper sulfate waste liquid; S2, adding Cu(OH)2 into the acidic copper sulfate waste liquid for neutralization treatment; S3, pumping the acidic copper sulfate waste liquid in the step S2 into a first evaporative crystallization device for crystallization and evaporation; S4, enabling the material in the step S3 to pass through a solid-liquid separation system to obtain a copper sulfate product, and discharging separated and evaporated mother liquor into an impurity removal reactor; S5, solid NaOH is added into the impurity removal reactor to generate Cu(OH)2 precipitate, the Cu(OH)2 precipitate is dehydrated and washed and then returns to the step S2, and supernate enters a second evaporative crystallization device or enters a factory sewage treatment station for further treatment; S6, crystallizing and evaporating the supernate by using a second evaporating crystallizer. The method has the advantages that the purity of the recovered product is high, new impurity ions are not introduced in the medicament adding process, the treatment process is stable in operation, and secondary pollutants are avoided.

Description

technical field [0001] The present application relates to the technical field of waste liquid treatment, and more particularly, to a method for recovering copper sulfate in acid copper sulfate waste liquid. Background technique [0002] The acid copper sulfate waste liquid is the copper sulfate consumption liquid in the electroplating tank discharged from the semiconductor wafer in the copper process and other processes. Its main components are copper sulfate and sulfuric acid. The weight ratio is about 15%. According to the "National Hazardous Waste List", the acid copper sulfate waste liquid belongs to the HW22 category of hazardous waste. If it is not treated effectively, it will not only pollute the environment but also waste resources. At present, the recycling technologies of acid copper sulfate waste liquid mainly include extraction-electrowinning recovery technology, eddy current electrolysis technology, ion exchange method, iron powder replacement recovery copper te...

AI Technical Summary

Problems solved by technology

The outstanding advantage of this technology is that it can recover high-purity copper products with a purity of 99.9%. The disadvantages are that the processing capacity is small, the organic copper extractant has emulsification, failure and other loss problems, and the pH adjustment process brings waste liquid volume increase, and the introduction of NH 4 + 、Na + , CO 3 2- Plasma and COD, after the incremental part is transferred to the waste liquid disposal company, it will also increase the difficulty of its standard discharge treatment

[0004] Chinese patent CN201220369211 introduces a vortex electrolysis technology. This technology is to add a vortex generator at the bottom of the traditional electrolytic cell. After the waste liquid is acted by the vortex generator, it forms a rapidly rotating fluid, which is in full contact with the cathode and anode surfaces of the electrolytic cell. It greatly improves the electrolysis efficiency, solves the problem of burning out the cathode due to the high electrolysis current density at high flow rate and the problem of easy short circuit due to the needle-shaped electrolyte on the upper part of the cathode. Although eddy current electrolysis has the above advantages compared with traditional electrolysis technology, However, it also has similar disadvantages to traditional electrolysis technology, that is, in acidic medium, the generated sediment will be dissolved in the waste liquid again, and the electrode plate needs to be replaced regularly, and the treatment cost is high

The advantage of this process is that the processing capacity is large, but its disadvantages are that the iron consumption is large, the purity of the recovered copper product is low, and a large amount of ferrous chloride waste liquid is produced, and the subsequent production of water treatment agent FeCl 3 The added value of resource utilization is low

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