Wet processing method for tin-copper slag

Abstract

The invention relates to a wet processing method for tin-copper slag. The method comprises the following steps that sulfuric acid and the tin-copper slag are put into a closed container according to aratio, and copper chloride is added according to 2-10 wt.% of the adding amount of the tin-copper slag; then oxygen is introduced into the closed container and pressurizing and heating are carried out, so that the tin-copper slag and the sulfuric acid are fully reacted under the action of an additive; a liquid-solid mass ratio of the sulfuric acid to the tin-copper slag is 4-8:1, and an initial acidity of a sulfuric acid solution is 100-200 g/l; the reaction pressure of the closed container is 0.8-2 Mpa, the reaction temperature is 120-200 DEG C, and the reaction time is 2-8 hours; and afterthe reaction is finished, solid-liquid separation is carried out, the leaching liquid is a copper sulfate solution, a copper sulfate product is obtained after concentrating and crystallizing, and theleaching residue is tin concentrate. According to the wet processing method for the tin-copper slag, the tin and the copper can be effectively separated, so that an open way of the copper is formed ina tin smelting system, and the processing cost of the tin-copper slag is reduced.

Description

technical field [0001] The invention belongs to the technical field of treatment methods for tin refining sulfur addition and copper removal slag. Background technique [0002] In the tin smelting process, after the tin concentrate is reduced and smelted into crude tin, due to the presence of copper in the tin smelting raw materials, the copper content in the crude tin is relatively high. Therefore, sulfur addition and copper removal operations are required to form a Tin-copper slag (also known as sulfur slag) with 10-30% copper and 30-80% tin. Most of the tin in this slag exists in the form of metal, oxide or alloy, and most of the copper exists in the form of copper sulfide. There are mainly the following methods for the treatment of such tin-copper slag at home and abroad: [0003] (1) Pyromelting: A certain proportion of flux is added to smelt in a short kiln to produce a semi-product of tin-copper alloy. Because a large amount of impurities in the slag enter the alloy...

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Problems solved by technology

[0003] (1) Pyromelting: A certain proportion of flux is mixed in a short kiln for smelting to produce semi-products of tin-copper alloy. Due to the large amount of impurities in the slag entering the alloy, it is difficult to further process the alloy product

[0004] (2) Roasting-leaching method: After the tin-copper slag is roasted, sulfuric acid is used to leaching the calcine, so that copper is opened from the tin smelting system in the form of copper sulfate products. This method has a low softening point of the tin-copper slag due to the existence of a large amount of metallic tin. , it is necessary to carry out multi-stage roasting to achieve the purpose of roasting without kiln formation and desulfurization, so that the roasting time is very long and the processing cost is high

Due to the existence of powdery copper sulfide in this method, the direct recovery rate of tin during electrolysis is low, and the current efficiency is low, resulting in poor economic benefits.

[0006] (4) Full wet process: Some researchers have conducted research on the full wet process of tin-copper slag, which is to decompose the tin-copper slag with hydrochloric acid, so that all the components in the slag enter the solution, and then carry out the treatment of each element in the solution. The separation of the method has the disadvantages of lengthy process flow and complicated process.

[0007] (5) fire-wet process: Tang Yunsheng, Li Yuanchang, Zhang Xionglin, Yang Chenglin, etc. proposed a treatment method for tin-copper slag, patent publication number CN1786226, using sulfuric acid for one-stage leaching, and the obtained stannous sulfate solution can be purified to obtain high-grade For stannous sulfate products, the first-stage leaching slag is oxidized and roasted, and then the sulfuric acid is leached in the second-stage to obtain a copper sulfate solution. The concentrated crystallization can produce copper sulfate products or enter the copper electrolysis system to produce copper. The second-stage leaching slag is the tin concentrate and returns to tin smelting system, this method has the disadvantage that the amount of metallic tin returned to tin smelting is relatively high

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