CN109913653B

CN109913653B - Method for separating indium and tin by vacuum vulcanization

Info

Publication number: CN109913653B
Application number: CN201910158655.4A
Authority: CN
Inventors: 邓勇; 杨斌; 徐宝强; 杨佳; 陈思峰; 郁青春; 王飞; 田阳; 张锋
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2019-03-04
Filing date: 2019-03-04
Publication date: 2020-09-04
Anticipated expiration: 2039-03-04
Also published as: CN109913653A

Abstract

The invention discloses a method for separating indium and tin by vacuum vulcanization, which comprises the following specific steps: mixing cuprous sulfide and indium tin alloy, putting the mixture into a vacuum furnace, heating to generate indium sulfide, volatilizing the indium sulfide into a gas phase, and enriching tin and copper in residues so as to realize the separation of indium and tin; the method is mainly characterized in that indium and tin are separated by a one-step vacuum vulcanization method according to the characteristics that the affinities of copper, indium and tin with sulfur are different, and the saturated vapor pressures of the generated indium sulfide, tin sulfide and copper sulfide are different.

Description

Method for separating indium and tin by vacuum vulcanization

Technical Field

The invention relates to a method for separating indium and tin by vacuum vulcanization, belonging to the technical field of indium extraction.

Background

The resource of indium is rare, and no ore body with industrial exploitation value exists in nature, and is mostly associated with non-ferrous metal sulfide, and the metal indium is mainly recovered from non-ferrous metal smelting by-products and indium secondary resources. In the smelting process, tin is often enriched and recovered together with indium due to the similar physicochemical properties of tin and indium. More than 80% of the indium yield is used for producing ITO, and leftover materials, waste targets or waste LCD materials generated in the production process are all mixtures of indium and tin.

The realization of the complete separation of indium and tin is the key of the recovery and regeneration of the production of high-purity metal indium and tin, and the currently known indium and tin separation technologies mainly comprise: hydrolysis method, displacement method, oxidation slagging method, fractional extraction method, distillation method and partial dilute acid method. Patent document CN101133172A discloses a "method and an apparatus for recovering indium from a waste liquid crystal display", in which a waste LCD is dissolved in hydrochloric acid, impurities of tin in the solution are removed by substitution with iron particles of 0.1 to 8mm, and the solution is neutralized with alkali to remove iron, thereby removing tin from the indium solution.

Patent document CN101532091A discloses a "process for separating valuable metals of lead, indium, antimony, copper and tin from lead smelting converter slag", in which caustic soda in an amount of 40 to 60% by weight of an alloy and sodium nitrate in an amount of 5 to 20% by weight of the alloy are added to an alloy containing lead, copper, antimony, indium and copper as an oxidizing agent, so that tin, antimony, indium and copper are oxidized into the slag, and the liquid-solid ratio of the oxidized slag is 3 to 5: 1 adding the copper, antimony and indium into the alkali aqueous solution to be ball-milled, and leaving the copper, antimony and indium in the slag, thereby realizing the separation of tin and indium.

Patent document CN1420184A discloses a method for extracting refined indium from indium tin oxide waste, which comprises dissolving indium tin oxide in an acid solution, adding hydrogen peroxide to separate indium and tin, and adding hydrogen peroxide to obtain Sn²⁺Oxidized to Sn⁴⁺And adding an inorganic coprecipitator (magnesium sulfate) to remove a compact precipitate generated by the tin, wherein the removal rate of the tin is more than 99%.

Patent document CN101701292A discloses a "method for recovering indium and tin from ITO waste target by oxidation method", which utilizes that tin has two states of divalent and tetravalent in solution, and the precipitation pH difference between tetravalent tin and trivalent indium ions in solution is large, controls a certain pH value, and uses hydrogen peroxide to oxidize tin ions into tetravalent by secondary oxidation to generate hydrolysis precipitation, while indium remains in aqueous solution, thereby realizing complete separation of indium and tin, and the tin content in the solution after separation is less than 2 ppm.

Patent document CN1487102A discloses a method for recovering indium from waste indium tin oxide targets, which comprises the steps of leaching, impurity removal, replacement, electrolysis and the like, wherein the impurity removal is carried out at 25-60 ℃ by using sponge indium or indium sheets as a purifying agent, and tin in the solution after the impurity removal is less than 0.1 g/L.

Patent document CN10163425A discloses "a method for extracting and separating indium and tin from an indium and tin mixed solution", wherein P is adopted in an acid solution system containing indium and tin₂₀₄Simultaneously extracting indium and tin, and then adopting 0.5-3 mol/l fluoride (HF, NaF, NH)₄F) And (3) complexing and back extracting tin, washing the back extraction raffinate with acid, and back extracting indium with 4-6 mol/l hydrochloric acid. Obtain a high-purity indium solution and a high-purity tin solution, and realize the complete separation of indium and tin.

Patent document CN102140580A discloses a "method for recovering multiple metals from flue dust generated in tin-making in an electric furnace", in which tin is separated from indium and tin by multi-stage extraction with 40% TBP, 10% sec-octanol and kerosene, and by multi-stage stripping with hydrofluoric acid.

Patent document CN101528988A discloses a "method for collecting valuable metals from ITO scrap", in which indium is collected by electrolyzing ITO scrap as an anode, an electrolytic cell is partitioned between the anode and a cathode by a diaphragm or an anion exchange membrane, an anolyte solution is extracted to remove tin, and a purified solution is charged into the cathode side and electrolyzed, thereby selectively collecting metallic indium. The method for removing tin can adopt a neutralization method, a replacement method, a metatitanic acid method, a hydrolysis method and the like, and a small amount of tin remains in the anolyte.

In patent document CN101104883A, a "method for recovering indium and tin from ITO scrap by acid leaching-sulfidation precipitation combined process" is disclosed, wherein sodium sulfide is added to indium and tin leachate to remove tin into sulfide precipitate from the solution.

In patent documents CN101660056, "method for separating indium and tin by vacuum distillation of indium-tin alloy" and CN201567361U, "a production apparatus for continuously removing tin from crude indium", a method and an apparatus for separating indium and tin by vacuum distillation are disclosed.

Patent document CN103194625A discloses a "separation method of tin-indium alloy", which sprays industrial oxygen with a purity of 93-98.5% onto the surface of tin-indium alloy at 850-1250 ℃, so that tin and indium are all oxidized into oxides, then uses 80-100 g/L of acid to leach, filters, reduces and melts the obtained filter residue to produce crude tin, and performs conventional extraction back extraction and replacement on the filtrate to obtain crude indium, thereby realizing separation of tin and indium.

Patent document CN1757768A discloses a "method for separating an indium-tin mixture", which adopts a method of leaching two-stage replacement to separate indium and tin, at present, zinc powder is added into an acid solution of the indium-tin mixture to replace tin ions with solid tin, solid-liquid separation is performed to realize separation of tin and indium, and after tin slag is soaked in concentrated nitric acid to remove impurities, the tin slag is reduced and smelted by coke powder to obtain crude tin; and replacing the tin-removed liquid by using a zinc sheet to obtain sponge indium, and performing briquetting-fusion casting to obtain crude indium.

Patent document CN101701291A discloses a method for recovering indium and tin from an ITO waste target by distillation, which utilizes SnCl at normal pressure₄Has a lower boiling point at normal pressure and is mixed with InCl₃The sublimation temperature is in a certain interval, and the chloride salt of the indium tin is separated by distillation. Leaching the ITO waste target with hydrochloric acid, adding a proper amount of oxidant after leaching to ensure that Sn is obtained²⁺Oxidized to Sn⁴⁺Distilling for 3-9 h at 120-140 ℃, respectively collecting distillate and retentate, dissolving the retentate with dilute hydrochloric acid, replacing with an aluminum plate, and performing alkali fusion to obtain crude indium.

Patent document CN101307385A discloses a method for treating a raw material containing indium, tin, zinc, and chlorine, comprising the steps of: washing with water to remove chlorine in the smoke raw material, adding the dechlorinated material into a pressure kettle, adding sulfuric acid, carrying out oxygen pressure heating leaching through oxygen, enabling indium and zinc to be leached into a solution, converting tin leaching into metastannic acid, precipitating into slag, realizing separation of indium and tin, and carrying out extraction, replacement and electrolysis on the zinc and indium solution to obtain metal indium.

En Ma describes in the literature a chlorinated volatilization process for the extraction of indium chloride: crushing ITO and mixing with NH₄Mixing Cl, heating to 250-450 ℃ in low vacuum or air, and forming volatile InCl from indium₃The recovery rate of indium can reach more than 99 percent after the indium is separated from tin. High purity of indium product, InCl₃Directly used for extracting the metal indium.

The method mainly solves the problem of reducing the content of impurity tin in the production and recovery processes of indium, mainly adopts a wet method, a vacuum distillation method or a sulfide precipitation method, and has the problems of long flow, incomplete indium-tin separation and the like.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for separating indium and tin by vacuum vulcanization, which realizes the separation of metal indium and tin mainly according to the characteristics that the affinities of metal copper, indium and tin with sulfur are different, and the saturated vapor pressures of the generated indium sulfide, tin sulfide and copper sulfide are different.

A method for separating indium and tin by vacuum vulcanization comprises the following specific steps:

cuprous sulfide and indium tin alloy are mixed, the mixture is placed into a vacuum furnace, sulfide of indium generated after heating is volatilized into a gas phase, and metal tin and copper are enriched in a residual liquid phase, so that the separation of indium and tin is realized.

And the cuprous sulfide is mixed with the indium-tin alloy according to the molar ratio of sulfur to indium in the cuprous sulfide of 1-1.2: 1.

The indium-tin alloy contains 10wt% -90 wt% of indium and 10wt% -90 wt% of tin.

The vacuum degree in the vacuum furnace is 5-20 Pa, the heating temperature is 800-1000 ℃, and the temperature is kept for 30-60 min.

The invention has the beneficial effects that: and separating the indium from the tin by a one-step vacuum vulcanization method.

Drawings

Fig. 1 is an XRD pattern of the distillate obtained in example 1.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

mixing cuprous sulfide and indium-tin alloy according to the molar ratio of sulfur in cuprous sulfide to indium in indium-tin alloy of 1.2:1, wherein the mass percent of indium in the indium-tin alloy is 90wt%, the mass percent of tin is 10wt%, putting the mixture into a graphite crucible, putting the graphite crucible into a vacuum furnace, controlling the vacuum degree in the vacuum furnace to be 5Pa, the temperature to be 800 ℃, volatilizing indium sulfide formed by metal indium into volatile matters, enriching metal tin and copper in a residue liquid phase, preserving heat for 60min, opening the vacuum furnace after cooling, and respectively taking out distillate and residue to realize the separation of metal indium and tin.

The taken-out distillate was condensed and subjected to XRD detection, and as shown in FIG. 1, the obtained XRD pattern corresponded perfectly to that of metal indium, indicating that the separation of metal indium and tin was achieved in this example.

Example 2

mixing cuprous sulfide and indium tin alloy according to the molar ratio of sulfur in the cuprous sulfide to indium in the indium tin alloy of 1:1, wherein the mass percent content of indium in the indium tin alloy is 10wt%, the mass percent content of tin is 90wt%, putting the mixture into a graphite crucible, putting the graphite crucible into a vacuum furnace, the vacuum degree in the vacuum furnace is 10Pa, the temperature is 900 ℃, the sulfide of indium formed by metal indium volatilizes into volatile matters, the metal tin and copper are enriched in a residual liquid phase, keeping the temperature for 40min, opening the vacuum furnace after cooling, and respectively taking out distillate and the residual, thereby realizing the separation of the metal indium and the tin.

Example 3

mixing cuprous sulfide and indium-tin alloy according to the molar ratio of sulfur in cuprous sulfide to indium in indium-tin alloy of 1.1:1, wherein the mass percent of indium in the indium-tin alloy is 60wt%, the mass percent of tin is 40wt%, putting the mixture into a graphite crucible, putting the graphite crucible into a vacuum furnace, controlling the vacuum degree in the vacuum furnace to be 20Pa, controlling the temperature to be 1000 ℃, volatilizing indium sulfide formed by metal indium into volatile matters, enriching metal tin and copper in a residue liquid phase, preserving heat for 30min, cooling, opening the vacuum furnace, and respectively taking out distillate and residue to realize the separation of metal indium and tin.

While the present invention has been described in detail with reference to the specific embodiments thereof, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described above, and that various changes and modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A method for separating indium and tin by vacuum vulcanization is characterized by comprising the following specific steps:

mixing cuprous sulfide with indium tin alloy, heating the mixture under a vacuum condition, volatilizing indium sulfide into a gas phase, and enriching tin and copper in residues to realize the separation of indium and tin; the cuprous sulfide is mixed with the indium-tin alloy according to the molar ratio of sulfur to indium in the cuprous sulfide of 1-1.2: 1; the indium content of the indium-tin alloy is 10-90% by mass, and the tin content of the indium-tin alloy is 10-90% by mass; the vacuum degree under the vacuum condition is 5-20 Pa, the heating temperature is 800-1000 ℃, and the temperature is kept for 30-60 min.