阅读说明：本技术 一种锡精炼硫渣氧压浸出同时回收铜和硫的方法 (Method for simultaneously recovering copper and sulfur by oxygen pressure leaching of tin refining sulfur slag ) 是由 张璋 杨从兴 杨成林 宋兴诚 王红彬 陈云 苏瑞春 李发祥 黄迎红 李鹏程 彭文 于 2020-06-16 设计创作，主要内容包括：一种锡精炼硫渣氧压浸出同时回收铜和硫的方法,将以质量含量计,含有锡50～70％、铜10～20％、硫7～10％的硫渣研磨后,与稀硫酸按液固质量比3～6:1混合,再添加硫渣质量2～10％的铁粉,加入氧压反应釜中,在200～240℃、氧分压1.5～3MPa的条件下浸出2～4h,然后过滤得到浸出渣与硫酸铜溶液；将浸出渣用水洗涤过滤得到脱除铜硫锡精矿产品,将硫酸铜溶液浓缩结晶后得到硫酸铜。本发明通过改变氧压浸出工艺条件及添加催化剂的方法,一次氧压浸出后得到脱除铜硫的锡精矿供锡熔炼工序使用,而铜与硫以硫酸铜的形式被回收方法简单,回收成本低,节能环保。(A method for recovering copper and sulfur simultaneously by oxygen pressure leaching of tin refining sulfur slag comprises the steps of grinding sulfur slag containing 50-70% of tin, 10-20% of copper and 7-10% of sulfur by mass, mixing the ground sulfur slag with dilute sulfuric acid according to the liquid-solid mass ratio of 3-6: 1, adding iron powder with the mass of 2-10% of the sulfur slag into an oxygen pressure reaction kettle, leaching for 2-4 hours under the conditions of 200-240 ℃ and 1.5-3 MPa of oxygen partial pressure, and filtering to obtain leaching slag and a copper sulfate solution; and washing and filtering the leached residues with water to obtain a copper-sulfur-tin-removed concentrate product, and concentrating and crystallizing a copper sulfate solution to obtain copper sulfate. By changing the oxygen pressure leaching process conditions and adding a catalyst, the tin concentrate without copper and sulfur is obtained after primary oxygen pressure leaching and is used for a tin smelting process, and the method for recovering copper and sulfur in a copper sulfate form is simple, low in recovery cost, energy-saving and environment-friendly.)

1. A method for simultaneously recovering copper and sulfur by oxygen pressure leaching of tin refining sulfur slag is characterized by comprising the following steps:

(1) grinding sulfur slag containing 50-70% of tin, 10-20% of copper and 7-10% of sulfur by mass, mixing the ground sulfur slag with dilute sulfuric acid according to the liquid-solid mass ratio of 3-6: 1, adding iron powder with the mass of 2-10% of the sulfur slag, adding the iron powder into an oxygen pressure reaction kettle, leaching for 2-4 hours at the temperature of 200-240 ℃ under the condition of the oxygen partial pressure of 1.5-3 MPa, and filtering to obtain leaching slag and a copper sulfate solution;

(2) washing and filtering leaching residues obtained in the step (1) with water to obtain a copper, sulfur and tin removal concentrate product;

(3) and (2) concentrating and crystallizing the copper sulfate solution obtained in the step (1) to obtain copper sulfate.

2. The method for simultaneous recovery of copper and sulfur by oxygen pressure leaching of tin refining sulfur slag as claimed in claim 1, wherein said tin refining sulfur slag is a refining slag produced by adding sulfur to remove copper during crude tin refining.

3. The method for simultaneously recovering copper and sulfur by oxygen pressure leaching of tin refining sulfur slag according to claim 1 or 2, characterized in that the initial concentration of dilute sulfuric acid used in the step (1) is 60-90 g/L.

4. The method for recovering copper and sulfur simultaneously by oxygen pressure leaching of tin refining sulfur slag according to claim 1 or 2, characterized in that in the step (2), a washing liquid after washing the leaching slag is returned to the step (1) as a leaching solution.

5. The method for recovering copper and sulfur simultaneously by oxygen pressure leaching of tin refining sulfur slag as claimed in claim 1 or 2, characterized in that, in the step (3), after the copper sulfate solution is concentrated and crystallized, the crystallization mother liquor rich in iron ions is returned to the step (1) as the leaching solution.

Technical Field

The invention belongs to the technical field of tin smelting, and particularly relates to a method for treating tin smelting intermediate slag.

Background

In the tin smelting technology, aiming at the treatment of sulfur slag, a plurality of different treatment processes have been developed, such as a diaphragm electrolysis-oxidizing roasting-acid leaching process, a flotation-oxidizing roasting-leaching process, a chlorination method for directly treating sulfur slag to produce industrial stannic chloride, a vacuum distillation method for producing stannous sulfide, a direct oxygen pressure leaching method for producing copper sulfate and the like. However, no efficient, energy-saving, clean and environment-friendly process is accepted by various large tin smelting plants, especially sulfur in the sulfur slag is not effectively recycled, and the treatment of the sulfur slag is still a difficult problem in the tin smelting process.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provide a method which can efficiently remove copper and sulfur in sulfur slag and simultaneously recover the copper and the sulfur.

The technical scheme adopted by the invention is as follows:

a method for simultaneously recovering copper and sulfur by oxygen pressure leaching of tin refining sulfur slag comprises the following steps:

(1) grinding sulfur slag containing 50-70% of tin, 10-20% of copper and 7-10% of sulfur by mass, mixing the ground sulfur slag with dilute sulfuric acid according to the liquid-solid mass ratio of 3-6: 1, adding iron powder with the mass of 2-10% of the sulfur slag, adding the iron powder into an oxygen pressure reaction kettle, leaching for 2-4 hours at the temperature of 200-240 ℃ under the condition of the oxygen partial pressure of 1.5-3 MPa, and filtering to obtain leaching slag and a copper sulfate solution;

(2) washing and filtering leaching residues obtained in the step (1) with water to obtain a copper, sulfur and tin removal concentrate product;

(3) and (2) concentrating and crystallizing the copper sulfate solution obtained in the step (1) to obtain copper sulfate.

The tin refining sulfur slag is the refining slag generated by adding sulfur and removing copper in the crude tin refining process.

The initial concentration of the sulfuric acid used in the step (1) is 60-90 g/L.

And (3) in the step (2), returning the washing liquid after washing the leaching residues to the step (1) as a leaching solution preparation.

In the step (3), after the copper sulfate solution is concentrated and crystallized, the crystallization mother liquor rich in iron ions is returned to the step (1) to be used as the leaching solution preparation.

In the process of oxygen pressure leaching, copper and sulfur in the sulfur slag enter a solution to generate copper sulfate, metallic tin forms insoluble beta stannic acid, tin existing in oxides is basically insoluble, tin, copper and sulfur are effectively separated, and sulfur is finally recovered in a copper sulfate form and is fully utilized because the sulfur is oxidized into sulfate radicals. In addition, after being dissolved in the leaching solution as a catalyst, the iron powder is used as an oxygen carrier to participate in the sulfur slag leaching reaction, but is not consumed, and only participates in the reaction in a mode of interconversion of ferric ions and ferrous ions, and finally, the iron powder is enriched in the copper sulfate crystallization mother liquor and can be recycled, so that the catalyst iron does not need to be added every time, the operation is simplified, and the recovery cost is reduced.

On the basis of the oxygen pressure leaching process, the invention provides a method for producing copper sulfate and tin concentrate for removing copper and sulfur in an economic and environment-friendly manner. The method is carried out under the conditions of higher reaction temperature, higher oxygen pressure, lower sulfuric acid concentration and addition of iron catalyst, can quickly oxidize the sulfur in the sulfur slag into sulfate radicals to enter a solution, does not remain in the slag in the form of elemental sulfur, and ensures that the copper enters the solution in the form of copper ions, thereby shortening the reaction time of oxygen pressure leaching and improving the production efficiency. The obtained tin concentrate is low in copper and sulfur, so that the desulfurization process of the tin concentrate is avoided, and the sulfur is prevented from entering flue gas, so that the environment-friendly treatment cost is reduced. The tin and copper are efficiently recovered in the whole process by a short flow, the sulfur is fully utilized, no wastewater or waste residue is generated in the process, and the process is energy-saving and environment-friendly.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The invention is further illustrated by the following figures and examples.