Method for preparing copper sulphate by using copper sponge without roasting and evaporating

Abstract

The invention provides a method for preparing copper sulfate from copper sponge without roasting or evaporation. The copper sponge is stored to allow it to naturally oxidize; and then a sulfuric acid solution with a concentration of 70-300g / L is used as a leaching agent at 80-98°C. The oxidized sponge copper is leached for 1 to 2.5 hours at a solid-to-liquid ratio of 1: 4 to 8 to obtain a slurry; the obtained leached slurry is filtered at 80 to 98°C to obtain the leachate and leaching residue respectively. ; Then the obtained leaching liquid is crystallized by conventional cooling, and then centrifuged to obtain copper sulfate and crystallization mother liquor. Sponge copper oxidation does not require roasting or adding oxidants. Metal copper and other elements in the raw materials are converted into acid-soluble oxidation states with the participation of air, which does not introduce impurities and is easy to operate. This invention does not have an evaporation and concentration process, and the production speed is fast. The water saving effect is obvious, the energy consumption is only about 10% of the traditional evaporation concentration process, and the energy consumption is significantly reduced.

Description

technical field [0001] The invention relates to a method for preparing copper sulfate crystals by using sponge copper produced by electrolysis or replacement as a raw material without roasting and evaporation, and belongs to the technical fields of hydrometallurgy and chemical industry. Background technique [0002] Some copper-containing materials such as copper ore, copper slag, red copper, and circuit boards are usually leached with sulfuric acid to obtain a low-concentration copper sulfate solution. Some non-ferrous metal smelting and electroplating processes also produce crude copper sulfate solution. This type of copper sulfate solution is replaced. Or electrodeposition and other means to obtain metallic sponge copper. This kind of sponge copper contains more impurities, the direct selling price is lower, the economic benefit is poor, the market demand is small, and the product with high value needs to be further processed. The production of copper sulfate is a kind of...

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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 leads to an increase in steam consumption. No matter whether it is the traditional methods and equipment to reduce steam consumption such as vacuum evaporation or multi-effect evaporation, this cannot be avoided. A core problem, which 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 in the concentrated liquid, 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, which will lead to an increase in raw material costs and economic benefits. For copper raw materials with high impurity content, in order to produce qualified products, various complicated purification processes are often used before evaporation and concentration, which leads to increased costs, reduced direct product recovery rate, and a large amount of purified slag.

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