Method for separating alumina and gallium from gallium-containing alumina by supergravity-vacuum airization combined separation

Abstract

The present application relates to a kind of supergravity-vacuum airization combined separation gallium-containing alumina and the method for separating alumina and gallium, belong to non-ferrous metal pyrometallurgy technical field.The present application is immersed in hot water with gallium-containing alumina, so that gallium is completely melted and presents liquid state, and alumina remains solid state to obtain liquid-solid two-phase mixture;Liquid-solid two-phase mixture is subjected to supergravity centrifugal separation to obtain solid-state alumina and aqueous gallium liquid phase;Aqueous gallium liquid phase is subjected to vacuum airization to make water completely volatilize to obtain gaseous water vapor and liquid phase gallium.The present application utilizes hot water melting and supergravity to realize the effective separation of alumina and gallium in gallium-containing alumina, and the drying of gallium, the whole process is physical process, with clean energy saving, hot water can be recycled, simple operation, easy to realize industrialization.

Description

Technical Field

[0001] This invention relates to a method for separating alumina and gallium in gallium-containing alumina using a combination of supergravity and vacuum vaporization, belonging to the field of pyrometallurgical technology for non-ferrous metals. Background Technology

[0002] Gallium is often found alongside bauxite, and over 90% of gallium is extracted from the alumina production process. Early methods employed neutralization precipitation, utilizing the different alkalinities of aluminum and gallium during hydrolysis to separate them. This process generated large amounts of waste and was costly, leading many aluminum plants to abandon gallium recovery, resulting in significant resource depletion. The amine oxime resin adsorption method is the mainstream technology for gallium recovery. Bayer process alumina seed liquor contains 100–300 mg / L of gallium. In sodium aluminate solution, the amine oxime chelating resin adsorbs only gallium, not aluminum. The gallium adsorbed on the resin can be eluted with alkaline or acidic solutions to obtain a gallium-rich solution, which can then be electrolyzed to obtain metallic gallium. However, amine oxime resins are unstable under acidic conditions and can only be used under alkaline and neutral conditions. Patent CN106986361A discloses a method for separating aluminum and gallium in the process of preparing alumina from fly ash using an acid method. The method involves gradually adding N,N-dimethyldithiocarbamate [(CH3)2NCSSM·2H2O] to an acidic aqueous solution of aluminum salts under stirring at a Fe3+:M+ molar ratio of 1:0.5-6. The reaction temperature is controlled at 5-40°C, producing a black precipitate. Solid-liquid separation yields an aluminum-containing solution and a gallium-containing precipitate residue. The acidic aqueous solution of the aluminum salts is an aluminum hydrochloric acid solution obtained by solid-liquid separation after extracting alumina from fly ash using an acid method to remove solid residue. However, this process generates a large amount of waste residue, posing significant environmental pressure and difficulty for subsequent treatment. Summary of the Invention

[0003] To address the difficulty of gallium recovery in existing technologies, which only allow for the adsorption and recovery of gallium from gallium-containing alumina under alkaline and neutral conditions, this invention proposes a method for the combined separation of alumina and gallium in gallium-containing alumina using a combination of hypergravity and vacuum vaporization. Specifically, by combining hypergravity and vacuum vaporization, gallium in the gallium-containing alumina is melted with hot water, and then the solid alumina is separated from the aqueous gallium liquid phase by hypergravity. The aqueous gallium liquid phase is then separated into gallium liquid and water vapor by vacuum vaporization, achieving efficient separation of alumina and gallium.

[0004] A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined hypergravity-vacuum vaporization approach, comprising the following specific steps:

[0005] (1) Gallium-containing aluminum oxide is immersed in hot water to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture;

[0006] (2) The liquid-solid two-phase mixture was separated by centrifugation under high gravity to obtain solid alumina and aqueous gallium liquid phase;

[0007] (3) Vacuum gasification of the water-containing gallium liquid phase to completely evaporate the water and obtain gas phase water vapor and liquid phase gallium.

[0008] In step (1), the aluminum oxide containing gallium contains 97-99 wt.% aluminum oxide and the remainder is gallium.

[0009] The hot water temperature in step (1) is 30-60℃.

[0010] The gravity of the centrifugal separation in step (2) is 5 to 300 G.

[0011] The time for centrifugation in step (2) is 30 to 60 minutes.

[0012] The vacuum aeration temperature in step (3) is 100-200℃.

[0013] The vacuum vaporization process in step (3) has a pressure of 100 to 1000 Pa.

[0014] The vacuuming time in step (3) is 10 to 60 minutes.

[0015] The beneficial effects of this invention are:

[0016] (1) This invention utilizes hot water to melt gallium and transform gallium into a liquid state, and then achieves effective separation of alumina and gallium through a combination of supergravity and vacuum vaporization. The whole process is a physical process, which has the characteristics of being clean and energy-saving, having recyclable hot water, being simple to operate, and being easy to industrialize.

[0017] (2) This invention utilizes the effect of centrifugal force field to transfer multiphase flow in liquid-solid two-phase mixture. Different components in the mixture, namely solid alumina and liquid gallium, are subjected to different centrifugal forces, thus enriching in different regions and achieving the purpose of separation.

[0018] (3) In the process of vacuum vaporization, water in the aqueous gallium liquid phase of the present invention is easily volatilized while gallium is not volatilized. The high-temperature water vapor condenses into hot water and is then returned to melt gallium in gallium-containing aluminum oxide. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0021] Example 1: A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined supergravity-vacuum vaporization method (see...) Figure 1 The specific steps are as follows:

[0022] (1) Gallium-containing aluminum oxide is immersed in hot water at 40°C to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture; wherein the gallium-containing aluminum oxide contains 97.8 wt.% aluminum oxide and 2.2 wt.% gallium.

[0023] (2) The liquid-solid two-phase mixture was separated by centrifugation under high gravity (the gravity of centrifugation was 10G) to obtain solid alumina and a water-containing gallium liquid phase;

[0024] (3) Place the aqueous gallium liquid phase in a vacuum furnace and evaporate it at a temperature of 100°C and a vacuum of 1000Pa to completely evaporate the water and obtain gaseous water vapor and liquid gallium; after the gaseous water vapor is condensed into hot water, it is returned to step (1) to melt gallium in gallium-containing aluminum oxide.

[0025] In this embodiment, the purity of solid alumina is 99.30%, and the purity of gallium is 93.78%.

[0026] Example 2: A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined hypergravity-vacuum vaporization method (see Example 2). Figure 1 The specific steps are as follows:

[0027] (1) Gallium-containing aluminum oxide is immersed in hot water at 35°C to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture; wherein the gallium-containing aluminum oxide contains 98.51 wt.% aluminum oxide and 1.49 wt.% gallium.

[0028] (2) The liquid-solid two-phase mixture was separated by centrifugation under high gravity (the gravity of centrifugation was 50G) to obtain solid alumina and a water-containing gallium liquid phase;

[0029] (3) Place the aqueous gallium liquid phase in a vacuum furnace and evaporate it under a vacuum of 150°C and 500Pa to completely evaporate the water and obtain gaseous water vapor and liquid gallium; after the gaseous water vapor is condensed into hot water, it is returned to step (1) to melt gallium in gallium-containing aluminum oxide;

[0030] In this embodiment, the purity of solid alumina is 99.65%, and the purity of gallium is 96.33%.

[0031] Example 3: A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined supergravity-vacuum vaporization approach, the specific steps of which are as follows:

[0032] (1) Gallium-containing aluminum oxide is immersed in hot water at 45°C to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture; wherein the gallium-containing aluminum oxide contains 99 wt.% aluminum oxide and 1 wt.% gallium.

[0033] (2) The liquid-solid two-phase mixture was separated by centrifugation under high gravity (the gravity of centrifugation was 200G) to obtain solid alumina and a water-containing gallium liquid phase;

[0034] (3) Place the water-containing gallium liquid phase in a vacuum furnace and evaporate it under a vacuum of 150°C and 200Pa to completely evaporate the water and obtain gaseous water vapor and liquid gallium; after the gaseous water vapor is condensed into hot water, it is returned to step (1) to melt gallium in gallium-containing aluminum oxide;

[0035] In this embodiment, the purity of solid alumina is 99.82%, and the purity of gallium is 98.47%.

[0036] Example 4: A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined hypergravity-vacuum vaporization approach, the specific steps of which are as follows:

[0037] (1) Gallium-containing aluminum oxide is immersed in hot water at 60°C to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture; wherein the gallium-containing aluminum oxide contains 99 wt.% aluminum oxide and 1 wt.% gallium.

[0038] (2) The liquid-solid two-phase mixture was separated by centrifugation under high gravity (the gravity of centrifugation was 300G) to obtain solid alumina and a water-containing gallium liquid phase;

[0039] (3) Place the aqueous gallium liquid phase in a vacuum furnace and evaporate it under the conditions of 200℃, 100Pa, and 60min to completely evaporate the water and obtain gaseous water vapor and liquid gallium; after the gaseous water vapor is condensed into hot water, it is returned to step (1) to melt gallium in gallium-containing aluminum oxide.

[0040] In this embodiment, the purity of solid alumina is 99.90%, and the purity of gallium is 99.13%.

[0041] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for separating aluminum oxide and gallium in gallium-containing aluminum oxide using a combined supergravity-vacuum vaporization method, characterized in that, The specific steps are as follows: (1) Gallium-containing aluminum oxide is immersed in hot water to completely melt gallium into a liquid state, while aluminum oxide remains solid to obtain a liquid-solid two-phase mixture; (2) The liquid-solid two-phase mixture is separated by centrifugation under high gravity to obtain solid alumina and aqueous gallium liquid phase; the gravity of the centrifugation is 5~300g; (3) Vacuum gasification of the aqueous gallium liquid phase to completely evaporate the water to obtain gaseous water vapor and liquid gallium; the vacuum gasification temperature is 100~200℃ and the vacuum gasification process pressure is 100~1000Pa.

2. The method for separating alumina and gallium in gallium-containing alumina using a combined hypergravity-vacuum vaporization method according to claim 1, characterized in that: In step (1), the aluminum oxide contains 97-99 wt.% aluminum oxide and the remainder is gallium.

3. The method for separating alumina and gallium in gallium-containing alumina using a combined hypergravity-vacuum vaporization method according to claim 1, characterized in that: Step (1) The hot water temperature is 30~60℃.

4. The method for separating alumina and gallium in gallium-containing alumina using a combined hypergravity-vacuum vaporization method according to claim 1, characterized in that: Step (2) The time for centrifugation under high gravity is 30~60 min.

5. The method for separating alumina and gallium in gallium-containing alumina using a combined hypergravity-vacuum vaporization method according to claim 1, characterized in that: Step (3) Vacuum aeration time is 10~60min.

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