Roasting-free evaporation-free method for producing cupric sulfate from zinc hydrometallurgy acid-wash copper dross

Abstract

The invention provides a method for producing copper sulfate from wet zinc smelting pickling copper slag without roasting or evaporation. The pickling copper slag is stored and allowed to oxidize naturally; a sulfuric acid solution with a concentration of 50-250g / L is used as a leaching agent. , leaching the oxidized pickled copper slag at a solid-to-liquid ratio of 1:3-6 at 75-100°C for 0.5-2.5 hours to obtain a slurry; then leaching the obtained slurry at 75-100°C Carry out filtration to obtain the leachate and leaching residue respectively; then the obtained leachate is crystallized by conventional cooling, and then centrifuged to obtain copper sulfate and crystallization mother liquor. The oxidation of pickling copper slag does not require roasting or adding oxidants, does not introduce impurities, and is simple to operate; the invention does not have an evaporation concentration process, has fast production speed, and obvious water-saving effects. The energy consumption is only about 10% of the traditional evaporation concentration process. Significantly reduced; the invention has a high comprehensive utilization rate of resources, no waste discharge, and little pressure on environmental protection.

Description

technical field [0001] The invention relates to a method for preparing copper sulfate crystals without roasting and evaporation from pickling copper slag produced in a zinc hydrometallurgy process, and belongs to the technical fields of hydrometallurgy and chemical industry. Background technique [0002] In the process of producing electric zinc by hydrometallurgy, the leaching solution containing zinc needs to be purified and removed. Usually, zinc powder is added to replace impurities such as copper and cadmium, and copper and cadmium slag is produced to recover zinc, copper, cadmium, and lead. Zinc, silver and other valuable elements are often leached out by pickling, soluble metals such as zinc, and zinc sulfate solution and pickling copper slag are produced. Copper in the pickling copper slag mainly exists in a metallic state. This type of copper slag contains more impurities, the direct selling price is lower, and the economic benefit is poor. It needs further treatmen...

AI Technical Summary

Problems solved by technology

From the perspective of solution evaporation, due to the high phase change heat of water, this process needs to absorb a large amount of energy; from the perspective of steam utilization, in order to ensure the evaporation speed of the solution, it is necessary to keep the solution in a boiling state, which is It will inevitably lead to the need to maintain a certain residual pressure of high-temperature and high-pressure steam, resulting in a large amount of lack of air, which eventually leads to a large consumption of steam. No matter whether it is the traditional methods and equipment to reduce steam consumption such as decompression evaporation or multi-effect evaporation, this core cannot be avoided. This is also the root cause of high energy consumption in the evaporation and concentration process

At the same time, in the process of evaporation and concentration, some impurities will reach supersaturation and precipitate out in the concentrated mother liquor, which will affect the quality of copper sulfate products. In order to ensure the quality of copper sulfate products, it is often necessary to use copper raw materials with less impurities, resulting in an increase in raw material costs and a decline in economic benefits. ; Although the method of purifying and removing impurities by solution has a certain effect, it also makes the operation complicated, increases the production cost, and introduces new impurities, and the purification slag produced will also reduce the copper recovery rate

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