RU2337165C2 - Method of extracting gallium out of alkali gallium containing solutions - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method includes treatment of source solution with liquid alloy of gallium and aluminium, at that treatment is performed by means of introducing gallium containing solution into liquid alloy of gallium and aluminium into bubbler under pressure. Solution is introduced at differential pressure in holes of the bubbler 0.01-1 MPa.

EFFECT: optimisation of volume exchange in process of gallium cementation; avoiding undesirable formation of aluminium hydroxide and simplification of design of cementation device.

1 dwg, 1 tbl, 1 ex

Description

The invention relates to the metallurgy of rare metals and can be used to extract gallium from alkaline solutions by cementation with liquid alloys, for example aluminum gallama.

A known method of extracting gallium from alkaline gallium-containing solutions by gallam aluminum cementation (USSR Author's Certificate No. 305768 IPC С22В, application 09.05.69, publ. 05.12.77), which provides for the combination of gallam preparation, gallium cementation with stirring at a speed of 150-250 rpm / min and the use of aluminum in the form of granules. The process is carried out with the mixing of gallam and solution in the total volume, which leads to a significant increase in the size of devices for its implementation.

Closest to the claimed technical solution (prototype) is a method of extracting gallium from alkaline solutions by cementing on aluminum gallam, implemented in a shelf type device (phase exchanger) (USSR Author's Certificate No. 1799926 IPC С22В 58/00, application 08.06.89, publ. 07.03 .93), which, at the same performance as the above-described analogue, takes up much less volume. This device implements the principle of counterflow of gallam and solution. However, both liquid phases are independently pumped, which complicates the implementation of the cementation process. The disadvantage of this device is the difficulty of transporting the alloy from the lower cavity of the housing to the upper. The transfer of aluminum gallam, regardless of the type of pump (centrifugal, diaphragm or induction), is inevitably accompanied by the absorption of a certain amount of alkaline solution, as a result of which aluminum hydroxide is formed in the pipeline, which, when accumulated on the walls, prevents the passage of gallam.

The objective of the invention is to optimize mass transfer during the cementation of gallium by gallam of aluminum from alkaline solutions, which will eliminate the negative formation of aluminum hydroxide, simplify the design of the corresponding devices, reduce their size and reduce the space they occupy.

The technical result is achieved by the fact that in the method of extracting gallium from alkaline gallium-containing solutions by cementation, including processing the solution with a liquid alloy, the gallium-containing solution is introduced into the liquid alloy of gallium with aluminum by sparging with a pressure drop in the holes of the bubbler of 0.01-1 MPa.

The drawing schematically shows one of the possible options for implementing the proposed method.

In the reactor 1, partially filled with liquid cementitious alloy 2, for example, aluminum gallama, a bubbler 3 is immersed in the form of a pipe with a sealed lower end and a perforated wall. The initial gallium-containing solution 4 is supplied under pressure through the upper end of the bubbler 3. Passing through the holes of the bubbler, the solution is introduced into the mass of liquid metal in the form of droplets 5, which float to the surface of the cementing alloy and simultaneously react with it. The droplets merged over the metal represent the spent solution 6.

Thus, in the process of cementing gallium on gallam aluminum, an alkaline solution is introduced into the liquid alloy by sparging with a pressure drop in the holes of the bubbler of 0.01-1 MPa. Moreover, the mass of the liquid alloy does not leave its reaction volume and undergoes intensive mixing. When the solution bubbles move through the gallam layer of aluminum, a large interfacial surface is created.

Such a technique leads not only to an acceleration of interphase exchange, but also to a change in the ratio of the rates of competing reduction processes of gallium and hydrogen ions in favor of the yield of the target product. In the proposed method of cementing gallium on gallam of aluminum, the interface surface is as developed as in the prototype, which favorably affects the process itself. However, there is no need for special transportation of the liquid alloy and the technical difficulties associated with this are eliminated. Compliance with the regime factor (differential pressure of the solution in the holes of the bubbler) within the claimed limits, on the one hand, ensures crushing of the jets of the solution into small drops at the outlet of the holes of the bubbler, i.e. provides a high specific gallam surface, and on the other hand, it prevents the dispersion of a liquid alloy in the spent solution when droplets exit the upper phase boundary.

Gallam is enriched with granular aluminum during the cementation process in the same reaction volume.

Examples of the method

Gallium was recovered by gallam cementation of aluminum from a solution containing, g / l: 175.6 caustic alkali, 0.30 gallium and 0.15 vanadium pentoxide. The solution was pumped from below through a gallam layer of aluminum in the reactor from below. Thus, the claimed principle of bubbling gallam with a solution was carried out. The discharge pipe was equipped with a pressure gauge. The pressure in the pipeline was controlled by changing the number of revolutions of the pump rotor. The maximum pressure created by the pump is 0.15 MPa. In the installation circulated 7 l of solution. The height of the gallam column was 150 mm. The spent solution was periodically taken and analyzed for gallium content, and based on these data, its extraction from the solution was calculated.

The results of the experiments are summarized in the table, from which it follows that in the claimed range of pressure drop in the bubbler holes (0.01-1 MPa), the cementation process is proceeding with high rates for this solution.

A decrease in the pressure drop below 0.01 MPa led to the jet regime of the outflow of the solution from the bubbler holes and, as a result, to a decrease in the interphase exchange surface, the useless “slip” of the solution through the gallam and a decrease in recovery. With an increase in the pressure drop above 1 MPa, dispersion of gallium and its loss due to chemical dissolution were observed (negative extraction in experiment 5).

Conditions and results of comparative experiments Experience number Way Pressure drop in the bubbler holes, MPa Extraction of gallium by time (from the beginning of the experiment),% 30 minutes 60 min 90 min one The claimed 0.010 29.8 53.3 63,4 2 0.5 51,2 70.1 81.5 3 1,0 38.9 56.7 73.3 four To beyond 0.05 5.1 9.8 13.7 5 1,1 10,2 0 -6.8

None of the experiments noted the formation of aluminum hydroxide, since the proposed method eliminates the forced circulation of gallam through a piping system. Accordingly, the absence of a circulation pump for pumping gallam simplifies the method, makes more rational and compact the design of any device for its implementation.

The proposed method allows to optimize the mass transfer of the cementation process of gallium by gallam of aluminum, to simplify the device for its implementation and to save production space.

Claims (1)

A method of extracting gallium from alkaline gallium-containing solutions by carburizing, comprising treating the solution with a liquid alloy of gallium with aluminum, characterized in that the treatment is carried out by introducing under pressure a gallium-containing solution into a liquid alloy of gallium with aluminum through a bubbler at a pressure drop in the holes of the bubbler of 0.01-1 MPa .