阅读说明：本技术 一种降低锡精炼渣中锡含量的方法 (Method for reducing tin content in tin refining slag ) 是由 张璋 王彦坤 杨从兴 刘庆东 周先辉 李鹏程 李正永 于 2020-07-31 设计创作，主要内容包括：本发明公开了一种降低锡精炼渣中锡含量的方法,在锡火法精炼除杂反应充分进行后,通过在精炼锅出渣前加入松香,以改善浮渣的流动性,使一部分机械夹杂锡又回到锡液中,在确保精炼脱杂效果满足生产要求的前提下,捞出的精炼渣含锡下降10～20个质量百分点。本发明使得锡精炼渣的机械夹杂锡量显著下降,提高了粗锡除铁、砷、铜、锑过程中的锡直收率,降低了锡精炼渣渣含锡,从而使锡精炼及锡渣处理两方面的经济效益都得到提升。(The invention discloses a method for reducing tin content in tin refining slag, which is characterized in that after the fire refining impurity removal reaction of tin is fully carried out, rosin is added before slag is discharged from a refining pot to improve the fluidity of floating slag, so that part of mechanical impurity-containing tin returns to tin liquid, and the tin content in the fished out refining slag is reduced by 10-20 mass percent on the premise of ensuring that the refining impurity removal effect meets the production requirement. The invention obviously reduces the mechanical tin content of the tin refining slag, improves the tin direct recovery rate in the process of removing iron, arsenic, copper and antimony from crude tin, and reduces the tin content of the tin refining slag, thereby improving the economic benefits of both tin refining and tin slag treatment.)

1. A method for reducing the tin content in tin refining slag is characterized by comprising the following steps: after the fire refining impurity removal reaction of tin is fully carried out, the additive is added before slag is discharged from the refining pot to improve the fluidity of floating slag, so that part of mechanical impurity-containing tin returns to the tin liquid, and the tin content of the fished refining slag is reduced by 10-20 mass percent on the premise of ensuring that the refining impurity removal effect meets the production requirement.

2. The method for reducing the tin content in the tin refining slag according to claim 1, characterized in that: the additive is rosin, and the addition amount is 1-5 wt.% of the amount of the treated crude tin.

3. The method for reducing the tin content in the tin refining slag according to the claim 1 or 2, characterized in that the adding mode of the additive is as follows:

1) controlling the temperature in a tin fire refining pot to be 240-360 ℃;

2) and mashing rosin, uniformly adding the mashed rosin into a tin fire refining pot, stirring and reacting for 5-15 min, and fishing out slag.

4. The method for reducing the tin content in the tin refining slag as claimed in claim 3, wherein the particle size of the crushed rosin is less than 3 mm.

5. The method for reducing the tin content in the tin refining slag according to claim 3, wherein the method is used for a condensation method iron and arsenic removal process of adding sawdust, a centrifuge liquation method iron and arsenic removal process, a sulfur adding copper removal process and an aluminum adding arsenic and antimony removal process.

Technical Field

The invention belongs to the technical field of non-ferrous metal smelting, and particularly relates to a method for reducing the content of tin in tin refining slag.

Background

Four impurities of iron, arsenic, copper and antimony in the crude tin are generally removed by a fire refining mode, the main process procedures are iron and arsenic removal by a liquation method, iron and arsenic removal by a condensation method, copper removal by adding sulfur and arsenic and antimony removal by adding aluminum, and refined tin slag produced in the fire refining process often contains a large amount of mechanically-doped metallic tin. The main reasons that the refined tin slag contains a large amount of mechanical impurity tin are as follows: the scum formed on the surface of the tin liquid in the refining impurity removal process has higher viscosity and poorer liquidity, so that the scum can wrap a large amount of metallic tin and enter refining slag in the slag dragging process, the direct yield of tin refining is reduced, the treatment capacity of the tin refining slag is increased, and the overall economic benefit of tin smelting is influenced. The tin content of carbon slag produced by a condensation method is 65-76 wt.%, the tin content of centrifugal slag produced by a centrifugal separation method is 38-49 wt.%, the tin content of sulfur slag produced by adding sulfur and removing copper is 55-65 wt.%, and the tin content of aluminum slag produced by adding aluminum and removing arsenic and antimony is 60-70 wt.%.

Because the fire refining impurity removal of tin mainly utilizes the difference principle of impurity elements or impurity compounds and tin melting points to realize the impurity removal process, the refining temperature is controlled strictly in the process of removing iron, arsenic, copper and antimony impurities in crude tin by fire refining, so that the liquidity of tin liquid and scum is improved by adjusting the refining temperature conventionally, and the reduction of mechanical tin inclusion in the slag fishing process is difficult to realize. In order to reduce the amount of tin inclusion in a tin pyrometallurgical refining machine, it is particularly necessary to find a method for reducing the content of tin in tin refining slag by improving the fluidity of refining dross and reducing the amount of tin inclusion in the dross machine.

Disclosure of Invention

Based on the problems in the prior art, the invention provides a method for reducing the tin content in tin refining slag on the premise of ensuring that the impurity removal effect of tin refining is not influenced, and the method is used for solving the problem of large tin content in mechanical slag inclusion of the tin refining slag.

The invention is realized by the following technical scheme:

a method for reducing the tin content in tin refining slag comprises the following steps: after the fire refining impurity removal reaction of tin is fully carried out, the additive is added before slag is discharged from the refining pot to improve the fluidity of floating slag, so that part of mechanical impurity-containing tin returns to the tin liquid, and the tin content of the fished refining slag is reduced by 10-20 mass percent on the premise of ensuring that the refining impurity removal effect meets the production requirement.

Preferably, the added additive is rosin, and the adding amount is 1 to 5 weight per thousand of the amount of the treated crude tin.

Preferably, the addition mode of the additive is as follows: 1) controlling the temperature in a tin fire refining pot to be 240-360 ℃; 2) and mashing rosin, uniformly adding the mashed rosin into a tin fire refining pot, stirring and reacting for 5-15 min, and fishing out slag.

Preferably, the particle size of the crushed rosin is less than 3 mm.

Preferably, the method is used for a condensation method iron and arsenic removing process of adding sawdust, a centrifuge liquation method iron and arsenic removing process, a sulfur adding copper removing process and an aluminum adding arsenic and antimony removing process.

The additive rosin is added after impurity-removing scum is completely formed, and the rosin and the scum float on the surface of the molten metal together without being mixed with the metal and introducing new impurities, so that the impurity-removing effect is not influenced.

Has the advantages that: according to the invention, the rosin is added before the slag is refined by the tin fire method to change the fluidity of the slag, so that the mechanical tin inclusion content of the tin refining slag is obviously reduced, the tin direct recovery rate in the process of removing iron, arsenic, copper and antimony from crude tin is improved, and the tin content of the tin refining slag is reduced, thereby improving the economic benefits of tin refining and tin slag treatment.

Drawings

FIG. 1 is a schematic view of a refining kettle of the present invention, wherein: 1-refining floating slag, 2-crude tin liquid, 3-rosin, 4-mechanical stirring device and 5-tin impurity removal pot.

Detailed Description

An embodiment of the present invention will now be described with reference to fig. 1. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention.