BE1029580B1 - PROCESS FOR SEPARATION AND PURIFICATION OF HIGH ANTIMONIUM CONTENT RAW TIN - Google Patents

Abstract

Method for separating and purifying high antimony crude tin: subjecting high antimony crude tin to vacuum gasification to form a mixed metal vapor; and introducing the mixed metal vapor into a fractional condenser connected to a vacuum gasification furnace and conducting condensation in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C and 100°C to 250°C to obtain a crude lead product, a crude antimony product and a crude arsenic product, respectively, and a refined tin product left after vacuum gasification.

Description

PROCESS FOR SEPARATION AND PURIFICATION OF HIGH ANTIMONY CONTAINING

RAW TIN

TECHNICAL AREA

The present disclosure relates to a method for separating and

Purification of raw tin with a high antimony content, which belongs to the technical field of

belongs to non-ferrous metal pyrometallurgy.

TECHNICAL BACKGROUND

[0002] Most smelters in the world are gradually removing

Impurities from the raw tin through a pyro-refining process. The Pyro

Refining mainly includes the following steps: removing iron and

arsenic by condensation, removal of copper by sulfur (sulphur slag),

Removal of arsenic and antimony by aluminum (aluminum slag), removal of

Lead and bismuth by crystallization separation and solder by vacuum distillation.

Aluminum slag, which generally contains 6% to 12% aluminum, 10% to 15% antimony, 1% to 3% arsenic, and 55% to 70% tin, is a hazardous waste. Improper disposal of aluminum slag can produce highly toxic arsine, which can cause death.

Most of the aluminum slag is smelted in the electric furnace to

Tin Antimony Arsenic Dust (which contains 30% to 35% tin, 0.5% to 1% arsenic and 2% to 4%

including antimony), electric furnace slags and high antimony raw tin (which includes 80% to 85% tin, 3% to 12% antimony and 1% to 2% arsenic). the tin

Antimony-arsenic dust is returned to the reduction smelter after arsenic removal, and the antimony re-enters the tin smelting system, causing accumulation there, which affects the normal operation of the tin smelting plant.

There are essentially three methods for treating high antimony crude tin: (1) A copper slag and an aluminum slag are mixed and smelted to produce crude tin with a high copper antimony content.

to produce lead-bismuth. And then the process of separating lead and

Bismuth from the raw tin by vacuum distillation used to make a Babbitt

to produce alloy. However, Babbitt alloy has low market demand and is generally produced at a relatively low selling price depending on sales. (2) Electrolysis: A raw tin alloy with a high antimony content is converted into a

Cast anode plate. The electrolysis was carried out at room temperature (25°C).

The electrolyte concentration was 70 g/L, the Sn* concentration was 60 g/L and the

Current density was 120 A/m°. The composition of tin in the product can reach 99.99%, and antimony enters the anode slime and electrolyte. The

Anode slime has a complex composition that makes it difficult to comprehensively treat valuable metals such as antimony and tin; also contains the

Electrolyte a large amount of arsenic, which is extremely harmful to the environment. (3) Two-stage high temperature and low temperature continuous vacuum distillation: the crude tin high in antimony is subjected to high temperature vacuum distillation to obtain crude tin and the tin-lead-antimony alloy | (with 25% to 30% Sn, 30%

Pb, 25% Sb); and from the tin-lead-antimony alloy | be through

Low-temperature vacuum distillation of a tin-antimony alloy (with 15.45%

Sb) and a lead-antimony alloy (with 40% Sb). This process allows the separate recovery of tin, lead and antimony and the removal of part of the antimony, but the percentage of antimony removal is only 50%.

The patent CN1156184A disclosed a method for the separation of

Antimony from raw tin containing antimony. The raw tin containing antimony had one

Antimony content of about 10%. The raw tin containing antimony is separated in a vacuum furnace. The temperature is 1,200℃-1,300℃, the residual pressure in the furnace is less than 13 Pa, and the distillation time is 30 minutes-120 minutes. By the

process, the impurity antimony is effectively separated and the content in the

Product reduced to no less than 1%. In the practice of vacuum distillation of

However, raw tin has been shown to volatize heavily when the

distillation temperature is above 1,200°C. Between tin and antimony im

Phase diagram of the Sn-Sb alloy, however, there are intermetallic Sb:2Sn:-

Links. Therefore, due to the volatilization of antimony, part of the tin can also escape from the melt. And the tin-lead-antimony alloys still need further processing. Ultimately, the direct yield of metallic tin is greatly reduced. Patent CN101696475B discloses a method for separating a ternary lead-tin-antimony alloy. The lead-tin-antimony ternary alloy was distilled by vacuum distillation at 900°C to 1,200°C for 40 min to 60 min at a

Degree of vacuum treated from 5 Pa to 15 Pa. The three components of the alloy are processed through a single-stage distillation. That is, the high-boiling tin remains liquid and the low-boiling lead and antimony volatize out of the alloy in gaseous form. This procedure is an extension of the ones already mentioned

CN1156184A to process the tin-lead-antimony alloy. A preserved

The residue, however, is the raw tin, which must be returned to the tin refining system for purification; and the Sn-Pb-Sb ternary alloy still present in the volatiles is not easily further processed.

As a result, the direct metal recovery rate is poor, and the separate

Recovery of the multi-component alloy cannot be achieved. Patent 201510059683.2 discloses a process for removing lead, antimony and arsenic from crude tin containing antimony by vacuum distillation. The crude tin containing antimony was subjected to primary continuous vacuum distillation to obtain refined

tin and a tin-lead-antimony alloy. And the tin-lead-antimony

alloy | was subjected to secondary continuous vacuum distillation and fractional condensation to obtain a tin-lead-antimony alloy II and a lead-antimony alloy. In this method, the primary continuous vacuum distillation must be carried out at 1,500°C to 1,700°C, which is much

energy consumed; moreover it is difficult with conventional

Vacuum distillation furnaces to achieve such a high temperature environment, and special vacuum furnaces are required, so the process has low universality

equipment has. On the other hand, since the temperature of the system is above the boiling point (1521°C) of tin under vacuum, a large amount of metallic tin may be volatilized, resulting in a low direct yield. Patent 201510060061.1 disclosed a process for separating antimony from a tin-antimony alloy by vacuum distillation. The tin-antimony alloy was continuously vacuum distilled to obtain crude tin and a tin-antimony mixed metal vapor, followed by conducting fractional condensation to obtain

Obtain crude antimony and a tin-antimony alloy separately. Also this one

Process requires extremely high temperature (1,000°C to 1,700°C) for the continuous vacuum distillation, and the continuous vacuum distillation must be repeated many times to obtain products that meet the requirements, resulting in increased labor and cost. Patent 202010547990.6 discloses a method for removing antimony in the

Tin smelting through a combination of pyrogenic processing and

wet processing. An aluminum slag obtained by adding aluminum to the

Removal of arsenic and antimony produced in the refining of crude tin was smelted with an electric furnace to obtain crude tin high in antimony, and vacuum distillation was carried out to obtain vacuum crude tin and a tin-lead-antimony

obtain alloy; the raw tin underwent electrolytic refining to obtain refined tin, and the tin-lead-antimony alloy underwent a second vacuum distillation to obtain a second vacuum raw tin and a

lead-antimony alloy separately. This process recovers tin economically; the antimony content of the obtained vacuum

However, raw tin is still relatively high (Sb less than 3% by weight); during electrolytic refining, a large amount of antimony gets into the anode slime, which is not easy for further processing.

EXECUTIVE SUMMARY

[0006] To overcome the deficiencies of the prior art, the present disclosure provides a method for separating and purifying crude tin high in antimony. The method solves the problem of in one

Tin refining system circulating antimony element, has a short process and does not generate "industrial effluent, exhaust gas and solid waste" and can recover valuable metals to the maximum extent. The process also has low

Treatment costs, a high metal recovery rate and direct yield, a pleasant working environment and a controllable process with safety. The present disclosure is realized by the following technical solutions.

The present disclosure provides a method for separating and

purification of high antimony crude tin which includes the following steps:

Step 1, implementation of a vacuum gasification of high antimony

raw tin so that volatile contaminating elements in the raw tin are maximally vaporized and volatilized to form a mixed metal vapor; and

Step 2, introducing the mixed metal vapor obtained in Step 1 into a fractional condenser connected to a vacuum gasification furnace and conducting condensation in condensation portions of the fractional

condenser at 550°C to 700°C, 300°C to 450°C and 100°C to 250°C to a

Crude lead product, a crude antimony product or a crude arsenic product and after the

vacuum gasification to obtain remaining refined tin product.

Furthermore, the raw tin high in antimony in step 1 can contain 70 wt.% to 95 wt.% Sn, 5 wt.% to 18 wt.% Sb, 0.5 wt.% to 10 wt.% Pb and 0.1 wt% to 5 wt% As.

Further, the vacuum gasification in step 1 may be performed at 900°C to 1,400°C and 1 Pa to 100 Pa for 30 minutes to 200 minutes.

The fractional condenser is made of a quartz material and is equipped with a resistance wire heating element and circulating cooling water to control the condensing temperature.

After processing by the method of the present disclosure, a refined tin product has greater than 99.9% Sn; Crude lead has 90% to 95% Pb, 4% to 10% Sn, 0.3% to 3% Sb and less than 1% As; Crude antimony has 90% to 98% Sb, 0.7% to 10% Pb and less than 1% As; and crude arsenic has 98% to 99% As.

In the present disclosure, tin, lead, antimony and arsenic each have a metal recovery rate of not less than 97%.

The present disclosure has the following advantageous effects:

The process purifies and refines raw tin in one step, recovers valuable metals such as lead, antimony and arsenic separately, and solves the problem of

Antimony element circulating in a tin refining system. The process significantly reduces enterprises' operating costs, has no "industrial effluent, exhaust gas and solid waste" generated during the process, and is safe, reliable and easy to operate. The process requires simple equipment and low

Cost and has high metal recovery efficiency and friendly

operating environment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 shows a process flow diagram of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The present disclosure will be described in more detail below with reference to the accompanying drawings and specific examples.

Example 1

As shown in FIG. 1, a process for separating and purifying high antimony crude tin involved the following steps:

In step 1, a vacuum gasification of 1 kg of high antimony

raw tin (a composition was shown in Table 1) was carried out at 1,400°C and 100 Pa for 200 minutes so that volatile impurity elements in the raw tin were vaporized and volatilized at maximum to form a mixed metal vapor; and

Table 1

[0023]

item | Sn | Pb | Sb | ace

Content (wt%) 71.65 16.72

In Step 2, the mixed metal vapor obtained in Step 1 was introduced into a fractional condenser connected to a vacuum gasification furnace, and condensation was carried out in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C °C and 100°C to 250°C to obtain a crude lead product, a crude antimony product, a crude arsenic product, and a refined tin product remaining after vacuum gasification; the fractional condenser being made of a quartz material and fitted with a resistance wire heating element and circulating cooling water to control the condensing temperature.

The tested product compositions of the crude lead product, des

Crude antimony product and crude arsenic product were shown in Table 2. The

Metal recoveries for tin, lead, antimony, and arsenic were 98.7%, 99.1%, 98.8%, and 99.4%, respectively.

Table 2 Product compositions (wt%)

[0027]

item product

Refined Crude Pb Crude Sb Crude As

Sn 99.96 5.26 - -

Pb - 91.68 9.16 -

Sb - 2.91 90.42 -

As - 0.15 0.82 98.75

Example 2

As shown in FIG. 1, a process for separating and purifying high antimony crude tin involved the following steps:

In step 1, a vacuum gasification of 1 kg of high antimony

raw tin (a composition was shown in Table 3) at 900°C and 1 Pa for 30 minutes so that impurity volatile elements in the raw tin were maximally vaporized and volatilized to form a mixed metal vapor; and

Table 3

[0032]

Element SN HD AS

Content (wt%) 88.48 3.87 6.39 1.26

In Step 2, the mixed metal vapor obtained in Step 1 was introduced into a fractional condenser connected to a vacuum gasification furnace, and condensation was carried out in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C °C and 100°C to 250°C to obtain a crude lead product, a crude antimony product, a crude arsenic product, and a refined tin product remaining after vacuum gasification; the fractional condenser being made of a quartz material and fitted with a resistance wire heating element and circulating cooling water to control the condensing temperature.

The tested product compositions of the crude lead product, des

Crude antimony product and crude arsenic product are shown in Table 4. The

Metal recoveries for tin, lead, antimony, and arsenic were 99.0%, 97.3%, 98.2%, and 99.6%, respectively.

Table 4 Product compositions (wt%)

[0036]

item product

Refined Sn Crude Pb Crude Sb Crude As

Sn 99.91 4.31 - -

Pb - 93.44 7.68 -

Sb - 1.88 91.60 -

As - 0.37 0.72 99.53

Example 3

As shown in FIG. 1, a process for separating and purifying high antimony crude tin involved the following steps:

In step 1, a vacuum gasification of 1 kg of high antimony

raw tin (a composition was shown in Table 5) at 1,200°C and 10 Pa for 30 minutes so that impurity volatile elements in the raw tin were maximally vaporized and volatilized to form a mixed metal vapor; and

Table 5

[0041]

In Step 2, the mixed metal vapor obtained in Step 1 was introduced into a fractional condenser connected to a vacuum gasification furnace, and condensation was carried out in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C °C and 100°C to 250°C to obtain a crude lead product, a crude antimony product, a crude arsenic product, and a refined tin product remaining after vacuum gasification; the fractional condenser being made of a quartz material and fitted with a resistance wire heating element and circulating cooling water to control the condensing temperature.

The tested product compositions of the crude lead product, des

Crude antimony product and crude arsenic product are shown in Table 6. The

Metal recoveries for tin, lead, antimony, and arsenic were 99.0%, 97.3%, 98.2%, and 99.6%, respectively.

Table 6 Product composition (wt%)

[0045]

item product

Refined Sn Crude Pb Crude Sb Crude As

Sn 99.90 7.66 - -

Pb - 91.10 2.63 -

Sb - 1.55 96.42 -

As - 0.09 0.95 98.97

Example 4

As shown in FIG. 1, a process for separating and purifying high antimony crude tin involved the following steps:

In step 1, a vacuum gasification of 1 kg of high antimony

raw tin (a composition was shown in Table 7) was carried out at 1,200°C and 10 Pa for 100 min so that impurity volatile elements in the raw tin were maximally vaporized and volatilized to form a mixed metal vapor; and

Table 7

[0050]

Content (wt%) 0.17

In Step 2, the mixed metal vapor obtained in Step 1 was introduced into a fractional condenser connected to a vacuum gasification furnace, and condensation was carried out in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C °C and 100°C to 250°C to obtain a crude lead product, a crude antimony product, a crude arsenic product, and a refined tin product remaining after vacuum gasification; the fractional condenser being made of a quartz material and fitted with a resistance wire heating element and circulating cooling water to control the condensing temperature.

The tested product compositions of the crude lead product, des

Crude antimony product and crude arsenic product are shown in Table 8. The

Metal recoveries for tin, lead, antimony, and arsenic were 98.6%, 98.9%, 99.2%, and 99.1%, respectively.

Table 8 Product composition (wt%)

[0054]

item product

Refined Sn Crude Pb Crude Sb Crude As

Sn 99.95 9.47 - -

Pb - 90.06 0.72 -

Sb - 0.36 98.81 -

As - 0.11 0.47 98.64

The examples of the disclosure are described in detail above with reference to the accompanying drawings, but the disclosure is not limited to the above examples. Various variations can also be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the disclosure.

Claims (3)

PATENT CLAIMS A method for separating and purifying high antimony crude tin, comprising the steps of: step 1, subjecting high antimony crude tin to vacuum gasification to obtain a mixed metal vapor; and Step 2, introducing the mixed metal vapor obtained in Step 1 into a fractional condenser connected to a vacuum gasification furnace, and conducting condensation in condensation sections of the fractional condenser at 550°C to 700°C, 300°C to 450°C and 100°C to 250°C to obtain a crude lead product, a crude antimony product, a crude arsenic product, and a refined tin product remaining after vacuum gasification. 2. A method for separating and purifying raw tin with a high antimony content according to claim 1, wherein in step 1 the raw tin with a high antimony content contains 70% by weight to 95% by weight Sn, 5% by weight to 18% by weight Sb, 0.5 wt% to 10 wt% Pb and 0.1 wt% to 5 wt% As. 3. The method for separating and purifying crude tin high in antimony according to claim 1, wherein in step 1, the vacuum gasification is carried out at 900°C to 1,400°C and 1 Pa to 100 Pa for 30 minutes to 200 minutes.