阅读说明：本技术 一种热态粗锡真空低能耗脱杂的方法 (Vacuum low-energy-consumption impurity removing method for thermal-state crude tin ) 是由 陈云 袁海滨 谢云华 唐都作 徐万立 丁剑 李俊杰 刘庆东 张瑜梅 李志禄 于 2021-09-26 设计创作，主要内容包括：一种热态粗锡真空低能耗脱杂的方法,将锡还原熔炼炉产出的粗锡,放入受锡锅后,在受锡锅上罩上真空罩；将真空罩通水进行冷却,同时开启真空泵,将真空罩抽真空至100Pa以下,并保持0.5h～2h,利用还原熔炼炉产出粗锡的余热进行热态粗锡的真空蒸馏脱杂；关闭真空泵,卸压到常压后,关闭冷却水将真空罩从受锡锅上移除；将冷凝在真空罩上的挥发物取下,即得到脱杂的热态粗锡。本发明有效利用了还原熔炼产出粗锡的余热,实现As、Bi、Pb、Sb等杂质与锡的分离,杂质脱除过程能耗低,高效、环保。(A method for removing impurities from hot crude tin in vacuum with low energy consumption comprises placing crude tin produced by a tin reduction smelting furnace into a tin receiving pot, and covering the tin receiving pot with a vacuum cover; cooling the vacuum cover by introducing water, simultaneously starting a vacuum pump, vacuumizing the vacuum cover to be below 100Pa, keeping for 0.5-2 h, and performing vacuum distillation and impurity removal on the thermal crude tin by using the waste heat of the crude tin produced by the reduction smelting furnace; closing the vacuum pump, releasing the pressure to normal pressure, and closing cooling water to remove the vacuum cover from the tin receiving pot; and taking off the volatile matter condensed on the vacuum hood to obtain the miscellaneous removed thermal state crude tin. The method effectively utilizes the waste heat of the crude tin produced by reduction smelting, realizes the separation of impurities such As As, Bi, Pb, Sb and the like from the tin, and has low energy consumption in the impurity removal process, high efficiency and environmental protection.)

1. A method for removing impurities from hot crude tin in vacuum with low energy consumption is characterized by comprising the following steps:

s1: putting the crude tin produced by the tin reduction smelting furnace into a tin receiving pot, and covering a vacuum cover on the tin receiving pot;

s2: cooling the vacuum cover by introducing water, simultaneously starting a vacuum pump, vacuumizing the vacuum cover to be below 100Pa, keeping for 0.5-2 h, performing vacuum distillation on the thermal crude tin by utilizing the waste heat of the crude tin produced by the reduction smelting furnace, and volatilizing As, Bi, Pb and Sb successively;

s3: closing the vacuum pump, releasing the pressure to normal pressure, and closing the cooling water;

s4: removing the vacuum hood from the tin receiving pot;

s5: and (3) taking off the volatile matters containing As, Bi, Pb and Sb condensed on the vacuum cover, and leaving the material in the tin receiving pot to be the miscellaneous hot crude tin.

2. The method according to claim 1, wherein in step S2, when the residual heat of the crude tin from the reduction smelting furnace is used for vacuum distillation, if the residual heat of the crude tin is insufficient, the tin pan can be heated for auxiliary heating.

3. The method for vacuum low-energy-consumption impurity removal of the hot crude tin according to claim 1 or 2, wherein the impurities removed by the vacuum distillation impurity removal of the hot crude tin are at least As, Bi, Pb and Sb.

4. The method for vacuum low-energy impurity removal of the crude tin in the thermal state according to claim 1 or 2, wherein the volatile matter containing As, Bi, Pb and Sb is high impurity crude lead.

5. The method for vacuum low-energy-consumption impurity removal of the crude tin in the thermal state according to claim 3, wherein the volatile matter containing As, Bi, Pb and Sb is high-impurity crude lead.

Technical Field

The invention belongs to the technical field of non-ferrous metal smelting, and particularly relates to a method for removing impurities from crude tin discharged by reduction smelting of tin concentrate or other tin-containing materials.

Background

The crude tin produced by reduction smelting of tin concentrates or other tin-containing materials contains many impurities, and even the tin refined from tin-rich concentrates generally does not meet the requirements of users. The common impurities in the crude tin include iron, arsenic, antimony, copper, lead, bismuth, sulfur and the like, which have great influence on the properties of tin, and in order to meet the quality requirement of the refined tin of a standard grade, the refining of tin is required, and in most cases, the comprehensive utilization rate of raw materials can be improved and the pollution to the environment can be reduced during the refining.

The fluctuation range of crude tin components produced by various smelting plants is large, and the fluctuation range mainly depends on the components of tin concentrate, the concentrate smelting pretreatment operation, the treatment process flow and the like. The crude tin refining comprises two methods of pyrometallurgy and hydrometallurgy (electrolysis), and the current crude tin refining method which is the mainstream in the world is pyrometallurgy. The advantages of pyrometallurgical processes are high productivity and no long-term stagnation of the metal in the production process, and a low amount of accumulated tin.

The raw tin of each tin refining plant contains different impurities, different production scales and different raw material supply and equipment conditions, so that the fire refining process is different. For crude tin produced by smelting high-grade concentrate with less impurities, such as Indonesia, Thailand and the like, refined tin can be obtained only by 1-2 fire refining operations, and the refining recovery rate (Thailand) reaches 99.45%. The fire refining process for treating crude tin with high impurity content is relatively long, for example, the Yunnan tin industry company in the old city of China adopts the fire refining principle process shown in figure 2 because the produced crude tin has high impurity content, wherein one or two impurities are removed in each operation, and some impurities are gradually removed in several operations. For example, arsenic is removed in three operations (centrifugal iron and arsenic removal, condensation iron and arsenic removal, and aluminum addition for arsenic and antimony removal).

The existing fire refining method of tin has poor operation environment, great environmental pollution and great labor intensity of workers in the lead and bismuth removing procedures of a continuous crystallizer, and can produce a great amount of refining slag rich in tin, thereby reducing the economic benefit of enterprises.

Disclosure of Invention

The invention aims to provide a method for removing impurities from hot crude tin in vacuum at low energy consumption, and solves the problems of poor production environment, large environmental pollution, high labor intensity of workers and the like in the conventional fire refining method for treating crude tin containing high impurities.

The technical scheme adopted by the invention is as follows:

a method for removing impurities from hot crude tin in vacuum with low energy consumption comprises the following steps:

s1: putting the crude tin produced by the tin reduction smelting furnace into a tin receiving pot, and covering a vacuum cover on the tin receiving pot;

s2: cooling the vacuum cover by introducing water, simultaneously starting a vacuum pump, vacuumizing the vacuum cover to be below 100Pa, keeping for 0.5-2 h, performing vacuum distillation on the thermal crude tin by utilizing the waste heat of the crude tin produced by the reduction smelting furnace, and volatilizing As, Bi, Pb and Sb successively;

s3: closing the vacuum pump, releasing the pressure to normal pressure, and closing the cooling water;

s4: removing the vacuum hood from the tin receiving pot;

s5: and (3) taking off the volatile matters containing As, Bi, Pb and Sb condensed on the vacuum cover, and leaving the material in the tin receiving pot to be the miscellaneous hot crude tin.

In the step S2, when the residual heat of the crude tin produced by the reduction smelting furnace is used for vacuum distillation, if the residual heat of the crude tin is insufficient, the tin pan can be heated for auxiliary heating.

Further, the impurities of the thermal state crude tin are removed by vacuum distillation, and the removed impurities are at least As, Bi, Pb and Sb.

Further, the volatile matter containing As, Bi, Pb and Sb is high impurity lead bullion.

The invention adopts vacuum distillation to remove impurities from the crude tin produced by the reduction smelting furnace, fully utilizes the waste heat of the crude tin produced by the reduction smelting (the crude tin produced by the reduction smelting of the crude tin is usually at the temperature of 900-1100 ℃) to carry out vacuum distillation, and separates impurities such As As, Bi, Pb, Sb and the like from the tin.

The invention adopts a vacuum distillation method, reduces the system pressure, and can volatilize the vapor pressure of lead, bismuth, arsenic and antimony which is higher than the system pressure at a temperature which is much lower than the boiling point of tin. As shown in table 1:

TABLE 1 vapor pressure of Sn, Pb, Bi, Sb and As as a function of temperature (K)

The temperatures used in the above table are thermodynamic temperatures, as a function of the temperature t in degrees Celsius: t (k) ═ 273.15+ t (° c).

The method effectively utilizes the waste heat of the crude tin produced by reduction smelting, realizes the separation of impurities such As As, Bi, Pb, Sb and the like from the tin, and has low energy consumption in the impurity removal process, high efficiency and environmental protection. After the crude tin is subjected to vacuum treatment, the impurity content is greatly reduced, the pressure of a subsequent refining system is reduced, the produced refining slag is greatly reduced, volatile matters can be directly sold, and the refining return investment is reduced.

The method is simple, easy to operate, green and environment-friendly, provides an effective way for impurity removal treatment of crude tin, and has wide application prospect.

Drawings

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

FIG. 2 is a flow diagram of a prior art fire refining process.

Detailed Description

The invention discloses a method for removing impurities from hot crude tin in vacuum with low energy consumption, and the process flow is shown in figure 1. The specific method comprises the following steps:

s1: smelting a tin-containing material in a reduction smelting furnace to obtain crude tin, putting the crude tin into a tin receiving pot, and covering a vacuum cover on the tin receiving pot;

s2: and (3) cooling the vacuum cover by introducing water, starting the vacuum pump at the same time, vacuumizing the vacuum cover to be below 100Pa, keeping for 0.5-2 h, performing vacuum distillation on the thermal crude tin by utilizing the waste heat of the crude tin produced by the reduction smelting furnace, and volatilizing and removing impurities such As As, Bi, Pb, Sb and the like in succession. The crude tin produced by the reduction smelting furnace is usually between 900 and 1150 ℃, is just below the vapor pressure of tin, and is on the vapor pressure of impurities such As As, Bi, Pb, Sb and the like, so that the tin can be separated from the impurities such As As, Bi, Pb, Sb and the like. The volatilization sequence is that Bi, Pb, Sb and As are added according to the required temperature from low to high. When the impurities are removed by vacuum distillation, if the residual heat of the crude tin is insufficient, the crude tin can be heated by a tin pan for auxiliary heating. Volatile matters generated during vacuum distillation impurity removal are high impurity lead bullion containing As, Bi, Pb and Sb, and can be directly sold;

s3: closing the vacuum pump, releasing the pressure to normal pressure, and closing the cooling water;

s4: removing the vacuum hood from the tin receiving pot;

s5: and (3) taking off the volatile matters containing As, Bi, Pb and Sb condensed on the vacuum cover, and leaving the material in the tin receiving pot to be the miscellaneous hot crude tin.

The tin receiving pot and the vacuum cover used in the method are all devices in the prior art.

Example 1

Putting the crude tin (components Sn 93%, As 1.5%, Pb 2%, Bi 0.4% and Sb 0.6%) produced by the reduction smelting furnace into a vacuum furnace, vacuumizing to below 10Pa, and performing vacuum volatilization for 1h to produce the crude tin with the following components: 95.5 percent of Sn, 0.54 percent of As, 0.31 percent of Pb, 0.06 percent of Bi and 0.25 percent of Sb, and the produced volatile substances comprise the following components: 28% of As, 50% of Pb, 10% of Bi and 10% of Sb. The crude tin component is greatly improved, and the treatment pressure of a subsequent refining system is reduced. The volatiles are sold as high lead bullion.

Example 2

Putting the crude tin (components Sn 91.5%, As 1%, Pb 3%, Bi 0.3% and Sb 0.8%) produced by the reduction smelting furnace into a vacuum furnace, vacuumizing to below 70Pa, and performing vacuum volatilization for 1.5h to produce crude tin components: 95.5 percent of Sn, 0.37 percent of As, 0.47 percent of Pb, 0.05 percent of Bi and 0.33 percent of Sb, and the produced volatile substances comprise the following components: 16% of As, 64% of Pb, 6% of Bi and 12% of Sb. The crude tin component is greatly improved, and the treatment pressure of a subsequent refining system is reduced. The volatiles are sold as high lead bullion.

Example 3

Putting the crude tin (components Sn 91.5%, As 0.5%, Pb 4%, Bi 0.2% and Sb0.3%) produced by the reduction smelting furnace into a vacuum furnace, vacuumizing to below 100Pa, and performing vacuum volatilization for 2 hours to produce crude tin components: 95.8% of Sn, 0.18% of As, 0.63% of Pb, 0.03% of Bi and 0.13% of Sb, and the produced volatile substances comprise the following components: as 8%, Pb 83%, Bi 4%, and Sb 4%. The crude tin component is greatly improved, and the treatment pressure of a subsequent refining system is reduced. The volatiles are sold as high lead bullion.

Effect analysis

The crude tin produced by the reduction smelting furnace is directly discharged into the vacuum furnace, the vacuum furnace is vacuumized to be below 100Pa, the residual heat of the crude tin is utilized to carry out vacuum volatilization for 0.5-2 h, so that impurity elements such As As, Bi, Pb, Sb and the like in the crude tin are volatilized in a gas form, and a multi-element alloy is formed by condensation and collection for sale, the impurity elements such As As, Bi, Pb, Sb and the like in the crude tin are greatly reduced, the pressure of a subsequent refining system is greatly reduced, meanwhile, the residual heat of the crude tin produced by the reduction smelting furnace is fully utilized.

Finally, the above embodiments and the accompanying drawings are only intended to illustrate the technical solution of the present invention and not to limit, and although the present invention has been described in detail by the above embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the present invention as defined by the claims.