阅读说明：本技术 一种联合火法与湿法工艺使锑在锡冶炼中开路的方法 (Method for opening circuit of antimony in tin smelting by combining pyrogenic process and wet process ) 是由 张璋 刘庆东 王彦坤 宋兴诚 杨从兴 杨德香 白家福 于 2020-06-16 设计创作，主要内容包括：一种联合火法与湿法工艺使锑在锡冶炼中开路的方法,首先将粗锡精炼加铝除砷锑产出的铝渣,用电炉熔炼后产出高锑粗锡,然后脱除铁、砷及铜,再进行真空蒸馏,分离得到真空粗锡和锡铅锑合金；把真空粗锡进行电解精炼,得到锡含量≥99.9wt.％的精锡产品；再把锡铅锑合金进行真空蒸馏,分离得到二次真空粗锡和铅锑合金。本发明将铝渣电炉熔炼产出的高锑粗锡,经真空蒸馏与电解精炼联合处理后产出了符合产品标准的产品精锡,并使锡冶炼流程中富集于铝渣的锑绝大部分以铅锑合金,少量以精炼阳极泥的方式从锡冶炼流程中开路,有效降低了锑在锡冶炼流程中的循环量,同时也减少了锡在精炼过程中的循环量,以较经济的方式回收了锡。(A method for opening a circuit in tin smelting of antimony by combining a pyrogenic process and a wet process comprises the steps of firstly refining crude tin, adding aluminum, removing arsenic and antimony to produce aluminum slag, smelting the aluminum slag by using an electric furnace to produce high-antimony crude tin, then removing iron, arsenic and copper, then carrying out vacuum distillation, and separating to obtain vacuum crude tin and tin-lead-antimony alloy; carrying out electrolytic refining on the vacuum crude tin to obtain a refined tin product with the tin content being more than or equal to 99.9 wt%; and then carrying out vacuum distillation on the tin-lead-antimony alloy, and separating to obtain secondary vacuum crude tin and lead-antimony alloy. According to the invention, the high-antimony crude tin produced by smelting the aluminum slag in the electric furnace is treated by combining vacuum distillation and electrolytic refining to produce the product refined tin meeting the product standard, most of antimony enriched in the aluminum slag in the tin smelting process is lead-antimony alloy, and a small amount of antimony is opened from the tin smelting process in a way of refining anode mud, so that the circulation amount of antimony in the tin smelting process is effectively reduced, the circulation amount of tin in the refining process is also reduced, and the tin is recovered in a more economic way.)

1. A method for opening a circuit of antimony in tin smelting by combining a pyrogenic process and a wet process is characterized by comprising the following steps:

(1) refining crude tin, adding aluminum, removing arsenic and antimony to produce aluminum slag, smelting the aluminum slag by using an electric furnace to produce high-antimony crude tin, then removing three impurities including iron, arsenic and copper, melting the high-antimony crude tin subjected to impurity pre-removal at the temperature of 350-550 ℃, continuously and uniformly adding the high-antimony crude tin into a vacuum furnace, carrying out vacuum distillation at the vacuum degree of 2-15 Pa and the distillation temperature of 1100-1250 ℃, and separating to obtain vacuum crude tin and a tin-lead-antimony alloy distilled and entering a condenser;

(2) casting the vacuum crude tin obtained in the step (1) at the temperature of 280-320 ℃ to form an anode plate, casting refined tin with tin content being more than or equal to 99.9 wt.% to form a cathode plate, carrying out electrolytic refining in electrolyte with silicofluoric acid as an electrolytic medium, adding sulfuric acid to purify the electrolyte, preventing lead from enriching and polluting cathode tin in the electrolyte, and finally obtaining refined tin product with tin content being more than or equal to 99.9 wt.% and anode mud;

(3) melting the tin-lead-antimony alloy obtained in the step (1) at the temperature of 450-650 ℃, continuously and uniformly adding the melted tin-lead-antimony alloy into a vacuum furnace, carrying out vacuum distillation under the conditions that the vacuum degree is controlled to be 2-5 Pa and the distillation temperature is 1250-1350 ℃, and separating to obtain secondary vacuum crude tin and the lead-antimony alloy distilled into a condenser; wherein, the secondary vacuum crude tin returns to the step (1) and is matched with the high-stibium crude tin for vacuum distillation treatment for a plurality of times in a small amount.

2. The method for opening antimony in tin smelting by combining a pyrogenic process and a wet process according to claim 1, wherein the high-antimony crude tin has a tin content of 80-85 wt.%, an antimony content of 6-10 wt.%, an arsenic content of 0.1-0.6 wt.%, and the balance of lead and bismuth.

3. The method for opening antimony in tin smelting by combining a pyrogenic process and a wet process according to claim 1, wherein the tin content of the vacuum crude tin produced in step (1) is not less than 95 wt.%, the antimony content is less than 3 wt.%, and the lead content is not more than 1 wt.%.

4. The method for opening antimony in tin smelting by combining the pyrometallurgical and hydrometallurgical processes according to claim 1, wherein the step (2) is an electrolytic refining of the vacuum crude tin, and the electrolytic refining condition is that a refined tin product is used as a cathode starting sheet; the cell voltage is 0.15-0.3V, the homopolar distance is 90mm, and the current density is 90-100A/m²The temperature of the electrolyte is 30-35 ℃, and the period is 4-5 d; the content of tin in the electrolyte is 25-45 g/L, the total quantity of silicofluoric acid is 100-150 g/L, sulfuric acid is supplemented to 5-10 g/L each time, and the electrolyte circularly flows.

5. A combined pyrometallurgical and hydrometallurgical process for opening antimony in tin smelting according to claim 1, characterized in that the lead-antimony alloy produced in step (3) has a tin content of < 1 wt.%.

Technical Field

The invention belongs to the technical field of tin smelting, and particularly relates to a combined pyrogenic process and wet process, which is a method for realizing antimony open circuit in tin smelting by treating high-antimony crude tin by combining vacuum distillation and electrolytic refining.

Background

In the tin smelting industry, it has been a difficult problem to open a circuit from a tin smelting process in an economical and environment-friendly manner. In the tin refining process, antimony is generally removed in a manner of adding aluminum particles to form a high-melting-point aluminum-antimony compound, and aluminum slag with high tin content is obtained. In the past, when the amount of antimony-containing low-aluminum slag in the raw material is less, the aluminum slag is usually smelted to produce a tin-antimony alloy, and the tin-antimony alloy is purified and then sold as a tin-based bearing alloy. However, in recent years, due to the increase of the content of antimony impurities in raw ores and the use of a large amount of secondary antimony-containing tin raw materials, the amount of antimony entering a tin smelting process is increased, so that the amount of aluminum slag is also obviously increased, a large amount of tin is taken away by the aluminum slag, and the open circuit of antimony is realized in a tin-antimony alloy mode because the price of the tin-antimony alloy is not high and the market demand is small, which is particularly uneconomical.

Therefore, in recent years, a plurality of effective antimony open-circuit processes for smelting tin are proposed, wherein the front end of the processes is to smelt antimony-enriched aluminum slag in an electric furnace to produce high-antimony crude tin, and then a treatment process is designed for the high-antimony crude tin. Wherein the vacuum distillation is mature, the application range of the raw materials is wide, and the application is wide. However, the vacuum distillation method also has its drawbacks. For example, the general processing method of the vacuum distillation method is that vacuum tin with antimony content less than 1 wt.% is produced and returned to the tin fire refining process, and in order to achieve the purpose, a vacuum furnace needs to have higher vacuum degree, distillation temperature and longer distillation time, even the same batch of materials needs to be distilled for many times, so that a large amount of tin is volatilized along with antimony, the direct yield of the vacuum distillation tin is low, and the volatilized tin-antimony-lead alloy is difficult to process.

In addition, in the patent with publication number CN102978657A, an electrolytic method is adopted to treat crude tin with high antimony content of 85-95 wt.% and 3-10 wt.% of antimony, the crude tin with tin content of more than 99 wt.% is used as a cathode plate, a mixed solution of silicofluoric acid and sulfuric acid is used as an electrolyte, and antimony open circuit is realized in a manner that antimony is left in anode mud. However, in the description of the patent, the anode slime rate is high, all above 20%, due to the high content of antimony in the anode, a large amount of tin is also brought into the anode slime, and the final product is crude tin, which needs to be returned to the fire refining treatment. Although antimony can be removed to the anode slime in one step, the product needs further treatment due to the excessive amount of the anode slime, and the economic efficiency is not ideal enough.

The method of simply using vacuum distillation (pyrogenic process) or electrolytic refining (wet process) to treat high-antimony crude tin cannot economically and efficiently recover tin and open antimony circuit for large-scale tin smelting plants, so that an antimony open circuit method integrating the advantages of the vacuum distillation and the electrolytic refining is needed.

Disclosure of Invention

Aiming at the problems and the defects of the prior art, the invention provides a method for opening a circuit in tin smelting by combining a pyrogenic process and a wet process, namely a method for treating high-antimony crude tin by combining vacuum distillation and electrolytic refining.

The technical scheme adopted by the invention is as follows:

a method for opening a circuit of antimony in tin smelting by combining a pyrogenic process and a wet process comprises the following steps:

(1) refining crude tin, adding aluminum, removing arsenic and antimony to produce aluminum slag, smelting the aluminum slag by using an electric furnace to produce high-antimony crude tin, then removing three impurities including iron, arsenic and copper, melting the high-antimony crude tin subjected to impurity pre-removal at the temperature of 350-550 ℃, continuously and uniformly adding the high-antimony crude tin into a vacuum furnace, carrying out vacuum distillation at the vacuum degree of 2-15 Pa and the distillation temperature of 1100-1250 ℃, and separating to obtain vacuum crude tin and a tin-lead-antimony alloy distilled and entering a condenser;

(2) casting the vacuum crude tin obtained in the step (1) at the temperature of 280-320 ℃ to form an anode plate, casting refined tin with tin content being more than or equal to 99.9 wt.% to form a cathode plate, carrying out electrolytic refining in electrolyte with silicofluoric acid as an electrolytic medium, adding sulfuric acid to purify the electrolyte, preventing lead from enriching and polluting cathode tin in the electrolyte, and finally obtaining refined tin product with tin content being more than or equal to 99.9 wt.% and anode mud;

(3) melting the tin-lead-antimony alloy obtained in the step (1) at the temperature of 450-650 ℃, continuously and uniformly adding the melted tin-lead-antimony alloy into a vacuum furnace, carrying out vacuum distillation under the conditions that the vacuum degree is controlled to be 2-5 Pa and the distillation temperature is 1250-1350 ℃, and separating to obtain secondary vacuum crude tin and the lead-antimony alloy distilled into a condenser; wherein, the secondary vacuum crude tin returns to the step (1) and is matched with the high-stibium crude tin for vacuum distillation treatment for a plurality of times in small amount.

The high-antimony crude tin has a tin content of 80-85 wt.%, an antimony content of 6-10 wt.%, an arsenic content of 0.1-0.6 wt.%, and the balance of lead and bismuth.

Further, the tin content of the vacuum crude tin produced in the step (1) is more than or equal to 95 wt.%, the antimony content is less than 3 wt.%, and the lead content is less than or equal to 1 wt.%.

Further, the vacuum crude tin is subjected to electrolytic refining in the step (2), wherein the electrolytic refining condition is that a refined tin product is used as a cathode starting sheet; the cell voltage is 0.15-0.3V, the homopolar distance is 90mm, and the current density is 90-100A/m²The temperature of the electrolyte is 30-35 ℃, and the period is 4-5 d; the content of tin in the electrolyte is 25-45 g/L, the total quantity of silicofluoric acid is 100-150 g/L, sulfuric acid is supplemented to 5-10 g/L each time, and the electrolyte circularly flows.

Further, the lead-antimony alloy produced in the step (3) has a tin content of less than 1 wt.%.

Firstly, removing impurities such as iron, arsenic, copper and the like from high-antimony crude tin produced by smelting aluminum slag in an electric furnace in advance, then fully utilizing the characteristic that vacuum distillation can efficiently volatilize metal elements with lower boiling points, and removing most of antimony and lead and impurities such as bismuth and arsenic which are mixed in the high-antimony crude tin in advance under the process condition of controlling the amount of returned secondary distillation materials to be less; and then the refined tin is directly produced by carrying out electrolytic refining on the vacuum crude tin from vacuum distillation by utilizing the characteristic that the impurity elements with higher potential can be removed at one time in a certain impurity content range in the electrolytic refining.

Compared with the process of vacuum distillation until the content of antimony is less than 1 wt.% and then returning to fire refining for antimony removal, the method greatly reduces the circulating treatment amount of tin in the vacuum distillation process, increases the unit time treatment amount of the high-antimony crude tin vacuum distillation, and avoids the phenomenon that part of antimony in the high-antimony crude tin from aluminum slag smelting is converted into aluminum slag for circulation again. Compared with the electrolytic refining directly using high-antimony crude tin, the method avoids the phenomenon that the direct yield of the electrolytic refined tin is low because most tin enters anode mud, and the refined tin is directly produced after the electrolytic refining.

According to the invention, the high-antimony crude tin produced by smelting the aluminum slag in the electric furnace is treated by combining vacuum distillation and electrolytic refining to produce the product refined tin meeting the product standard, most of antimony enriched in the aluminum slag in the tin smelting process is lead-antimony alloy, and a small amount of antimony is opened from the tin smelting process in a way of refining anode mud, so that the circulation amount of antimony in the tin smelting process is effectively reduced, the circulation amount of tin in the refining process is also reduced, and the tin is recovered in a more economic way.

The method is suitable for treating the high-antimony crude tin produced by the aluminum slag with larger amount in a large tin smelting plant, can realize the economic and efficient open circuit of impurity antimony in the large tin smelting plant, and avoids the vicious circle of antimony in the tin smelting process to a great extent.

Drawings

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

Detailed Description

The invention is further described with reference to the following drawings and specific embodiments.