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

Abstract

The invention provides a roasting-free evaporation-free method for producing cupric sulfate from zinc hydrometallurgy acid-wash copper dross, which comprises the following steps: stacking acid-wash copper dross for autoxidation; leaching the oxidated acid-wash copper dross at 75-100 DEG C according to a solid-to-liquid ratio of 1:(3-6) for 0.5-2.5 hours by using a 50-250g / L sulfuric acid solution as a leaching agent, thereby obtaining a slurry; filtering the leached slurry at 75-100 DEG C to respectively obtain a leach solution and a leached mud; and conventionally cooling to crystallize the leach solution, and carrying out centrifugal separation to obtain cupric sulfate and crystallization mother liquor. The oxidation of the acid-wash copper dross does not need roasting or addition of any oxidant, does not introduce any impurity, and is simple to operate. The invention does not have the process of concentration by evaporation, has the advantages of high production rate, obvious water-saving effect and obviously lower energy consumption (only about 10% of the traditional technique of concentration by evaporation). The invention also has the advantages of high resource comprehensive utilization ratio, no waste discharge and low environmental protection pressure.

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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