Method for strengthening dissolution of vanadium in bauxite

Abstract

The invention discloses a method for strengthening dissolution of vanadium in bauxite, and belongs to the technical field of bauxite treatment. Mixing bauxite, circulating mother liquor, sodium bicarbonate and an additive, and performing high-temperature stirring dissolution; the dissolved ore pulp is subjected to sedimentation, seed precipitation and evaporation, obtained evaporation mother liquor is subjected to cooling precipitation, and vanadium slag is obtained; the additive is at least one of lithium aluminum hydride, sodium borohydride, hydrazine, sodium hypophosphite, ammonium sulfite, ferrous sulfate, ferrous chloride and ferrous nitrate. According to the method, sodium bicarbonate is added into the vanadium-containing bauxite, sodium bicarbonate and water are subjected to a reaction, microbubbles are generated, dissolution of vanadium in the bauxite is promoted, an additive is added into the bauxite, other metal ores associated in the bauxite are replaced out, in the cooling precipitation process, the content of aluminum-containing components doped in vanadium slag is low, and the aluminum-containing components can be recycled. The loss of aluminum oxide is small.

Description

Technical Field

[0001] The invention belongs to the technical field of bauxite processing, and in particular relates to a method for strengthening the dissolution of vanadium in bauxite. Background Art

[0002] Vanadium is an important strategic resource with good alloy properties and catalytic characteristics. It is widely used in metallurgy, chemical industry, electronics, new energy, aerospace and other fields, and has an irreplaceable position in the national economy and national defense construction. While strengthening the efficient utilization of such complex primary vanadium resources, seeking suitable alternative resources is of great significance to the sustainable development of my country's vanadium industry.

[0003] Aluminum ore is associated with many useful elements such as Ga, V, Li, RE, Nb, Ta, Ti, Sc, etc. In some areas, the above-mentioned symbiotic minerals often form industrially valuable deposits together with bauxite. Ga, V, Sc, etc. in bauxite have recycling value. Bauxite contains a certain amount of vanadium resources, which will enter the solution during the Bayer process, but its dissolution rate is low. Depending on the type of ore and dissolution conditions, only 10~30% of vanadium is dissolved, resulting in the loss of vanadium resources.

[0004] Patent CN11578738 A discloses a method for increasing the dissolution rate of vanadium in bauxite. The technology for increasing the dissolution rate of vanadium in bauxite mainly includes adding alkaline earth metal compounds (calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide) and liquid oxidants (hydrogen peroxide, hypochlorous acid). However, in this patent, the dissolution rate of vanadium in bauxite is still lower than 60%, and the loss of vanadium resources is still relatively serious. Moreover, the addition of such additives will cause the loss of aluminum oxide and the amount of red mud produced is large, which not only causes the loss of resources, but also increases the treatment cost of red mud.

[0005] Therefore, how to increase the dissolution rate of vanadium in bauxite and reduce the loss of alumina has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] In view of the problems of low vanadium dissolution rate and large loss of aluminum oxide in bauxite in the prior art, the present invention provides a method for strengthening the dissolution of vanadium in bauxite. By using the method provided by the present invention, the dissolution rate of vanadium in bauxite can be increased to more than 70%, and the loss of aluminum oxide is small, and the amount of red mud produced is low, which is conducive to promotion and application.

[0007] The present invention is achieved through the following technical solutions: A method for enhancing the dissolution of vanadium in bauxite comprises the following steps: (1) Mixing bauxite, circulating mother liquor, sodium bicarbonate and additives, and performing high temperature stirring and dissolution; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag; The additive is at least one of lithium aluminum hydride, sodium borohydride, hydrazine, sodium hypophosphite, ammonium sulfite, ferrous sulfate, ferrous chloride and ferrous nitrate.

[0008] Furthermore, in step (1), the high temperature stirring dissolution temperature is 200-300° C., and the time is 60-120 min.

[0009] Furthermore, the amount of the additive added is 2-5% of the mass of the dry bauxite; the amount of the sodium bicarbonate added is 0.05-0.1% of the mass of the dry bauxite.

[0010] Furthermore, the additive is a mixture of lithium aluminum hydride and sodium hypophosphite.

[0011] Furthermore, the mass ratio of the lithium aluminum hydride to the sodium hypophosphite is 2-5:1.

[0012] Furthermore, in step (1), the V2O5 content in the bauxite is ≥ 0.2%.

[0013] Furthermore, in step (1), the V2O5 content in the bauxite is 0.02-2%.

[0014] Furthermore, in step (1), the bauxite has a particle size of ≤200 mesh.

[0015] Furthermore, the alkali concentration in the circulating mother liquor of step (1) is 150-260 g / L.

[0016] Beneficial Effects The present invention adds sodium bicarbonate to vanadium-containing bauxite, and the sodium bicarbonate reacts with water to generate microbubbles, thereby promoting the dissolution of vanadium in the bauxite. The additive is added to the bauxite to replace other metal ores associated with the bauxite. In the process of cooling and precipitation, the content of aluminum-containing components doped in the vanadium slag is low, and the loss of aluminum oxide is small. DETAILED DESCRIPTION

[0017] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0018] In the present invention, the mass content of vanadium in the bauxite is 0.042%, the alkali concentration in the circulating mother liquor is 210 g / L, and the bauxite is sieved through a 200-mesh sieve after being crushed.

[0019] Example 1 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.08% of the mass of the dry bauxite, the additives are lithium aluminum hydride and sodium hypophosphite (the mass ratio of lithium aluminum hydride to sodium hypophosphite is 3:1), the amount of additives added is 4% of the mass of the dry bauxite, the high-temperature stirring dissolution temperature is 290°C, and the time is 100 minutes; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 76%, and the aluminum oxide content in the vanadium slag is 8%.

[0020] Example 2 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.05% of the dry mass of the bauxite, the additive is lithium aluminum hydride, the amount of the additive added is 4% of the dry mass of the bauxite, the high-temperature stirring dissolution temperature is 280°C, and the time is 100 minutes; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 71%, and the aluminum oxide content in the vanadium slag is 10%.

[0021] Example 3 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.1% of the dry mass of the bauxite, the additive is ferrous sulfate, the amount of the additive added is 4% of the dry mass of the bauxite, the high-temperature stirring dissolution temperature is 270°C, and the time is 80 minutes; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 65%, and the aluminum oxide content in the vanadium slag is 15%.

[0022] Example 4 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.08% of the mass of the dry bauxite, the additives are lithium aluminum hydride and ferrous sulfate (the mass ratio of lithium aluminum hydride to ferrous sulfate is 3:1), the amount of the additive added is 4% of the mass of the dry bauxite, the high-temperature stirring dissolution temperature is 260°C, and the time is 80 minutes; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 69%, and the aluminum oxide content in the vanadium slag is 12%.

[0023] Example 5 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.06% of the mass of the dry bauxite, the additives are lithium aluminum hydride and ammonium sulfite (the mass ratio of lithium aluminum hydride to ammonium sulfite is 3:1), the amount of additives added is 4% of the mass of the dry bauxite, the high-temperature stirring dissolution temperature is 240°C, and the time is 120 min; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 72%, and the aluminum oxide content in the vanadium slag is 11%.

[0024] Example 6 (1) Bauxite, circulating mother liquor, sodium bicarbonate and additives are mixed and subjected to high-temperature stirring dissolution; wherein the amount of sodium bicarbonate added is 0.08% of the mass of the dry bauxite, the additives are lithium aluminum hydride and ferrous chloride (the mass ratio of lithium aluminum hydride to ferrous chloride is 3:1), the amount of the additive added is 4% of the mass of the dry bauxite, the high-temperature stirring dissolution temperature is 280°C, and the time is 100 minutes; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag. The vanadium content and aluminum content in the vanadium slag are tested. The calculated vanadium dissolution rate is 69%, and the aluminum oxide content in the vanadium slag is 12%.

[0025] Comparative Example 1 Different from Example 1, sodium bicarbonate was not added in Comparative Example 1, and other steps were the same as those in Example 1. The obtained vanadium slag had a vanadium dissolution rate of 62% and an aluminum oxide content of 14%.

[0026] Comparative Example 2 Different from Example 1, the additives in Comparative Example 2 and other steps are the same as those in Example 1. The obtained vanadium slag has a vanadium dissolution rate of 32% and an aluminum oxide content of 61%.

Claims

1. A method for enhancing the dissolution of vanadium in bauxite, characterized in that: The following steps are involved: (1) Mixing bauxite, circulating mother liquor, sodium bicarbonate and additives, and performing high temperature stirring and dissolution; (2) The dissolved ore pulp is subjected to sedimentation, seed separation, evaporation, and the obtained evaporated mother liquor is cooled and precipitated to obtain vanadium slag; The additive is at least one of lithium aluminum hydride, sodium borohydride, hydrazine, sodium hypophosphite, ammonium sulfite, ferrous sulfate, ferrous chloride and ferrous nitrate.

2. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: In step (1), the high temperature stirring dissolution temperature is 200-300°C and the time is 60-120 minutes.

3. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: The amount of the additive added is 2-5% of the mass of the dry bauxite; the amount of the sodium bicarbonate added is 0.05-0.1% of the mass of the dry bauxite.

4. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: The additive is a mixture of lithium aluminum hydride and sodium hypophosphite.

5. The method for enhancing vanadium dissolution in bauxite according to claim 4, characterized in that: The mass ratio of lithium aluminum hydride to sodium hypophosphite is 2-5:

1.

6. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: In step (1), the V2O5 content in the bauxite is ≥ 0.2%.

7. The method for enhancing vanadium dissolution in bauxite according to claim 6, characterized in that: The V2O5 content in the bauxite in step (1) is 0.02-2%.

8. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: In step (1), the bauxite has a particle size of ≤200 mesh.

9. The method for enhancing vanadium dissolution in bauxite according to claim 1, characterized in that: The alkali concentration in the circulating mother liquor of step (1) is 150-260 g / L.