Method for extracting aluminum and iron from high iron gibbsite-type bauxite

Abstract

The invention relates to a method for separating and extracting aluminum and iron in bauxite by treating high iron gibbsite-type bauxite by using an alkali medium two-stage wet dissolution process. The primary dissolution of the method comprises the following steps: dissolving out easily dissoluble aluminum component in the high iron gibbsite-type bauxite at low temperature by using a sodium aluminate solution in low alkali concentration, separating liquid from solid, seed-precipitating the primary dissolved solution to obtain an aluminum hydroxide product, and returning the seed-precipitating mother solution for dissolving out the bauxite; the secondary dissolution comprises the following steps: treating primary dissolved slag at a high temperature high-alkaline condition by using an alkali liquor in high molecular ratio or low molecular ratio, feeding aluminum and silicon in the slag into a liquid phase, separating liquid from solid to obtain iron-enriched slag, returning the liquid phase for treating the primary dissolves slag after diluting and removing aluminum and silicone, evaporating and concentrating. The process flow of the method is simple, the separating effect of the iron and the aluminum is obvious so as to respectively obtain aluminum oxide and iron-enriched slag, the iron-enriched slag can be directly used as iron making raw material, and an efficient method for utilizing the high iron bauxite resource in China.

Description

technical field

[0001] The invention relates to a method for extracting aluminum and iron from high-iron gibbsite bauxite, in particular to a method for extracting aluminum and iron respectively by two-stage wet stripping in an alkali medium. Background technique

[0002] Aluminum is the second largest metal material after steel. It has a wide range of uses, and its correlation with the national economy is as high as 91%. It is a major pillar industry of the country. As the upstream of the aluminum industry, the output of alumina basic raw materials has been growing steadily. In 2012, my country's alumina output reached 37.72 million tons, accounting for more than 1 / 3 of the world's total output. Bauxite is the main raw material for the production of alumina. However, my country's bauxite reserves only account for 1.5% of the world's reserves. According to the current bauxite consumption per ton of alumina production, the guarantee period for my country's bauxite resources i...

Examples

Embodiment 1

[0030] Configure Na 2 Sodium aluminate solution with an O concentration of 100g / L and a molecular ratio of 3.0, mix the high-iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume mass ratio 7:1), and the molecular ratio of the ingredients is 1.47 at this time. The mixed slurry was reacted at 100°C for 60 minutes, and the liquid-solid separation was carried out while the reaction was hot, and the resulting eluate directly entered the seeding process to extract aluminum hydroxide without adjusting the alkali concentration; configure Na 2 O concentration 300g / L, the sodium aluminate solution of molecular ratio 1.6, one section stripping slag is mixed with this sodium aluminate solution by liquid-solid ratio 20, and mixed slurry is placed in autoclave at 260 ℃ of reaction 1h, After the reaction is completed, liquid-solid separation is carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content of up to 80.45%, dilute the seco...

Embodiment 2

[0032] Configure Na 2 Sodium aluminate solution with an O concentration of 250g / L and a molecular ratio of 4.0, mix the high-iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume-to-mass ratio) of 3:1. At this time, the molecular ratio of the ingredients is 1.74. The mixed slurry was reacted at 130°C for 20min, and the liquid-solid separation was carried out while the reaction was hot, and the obtained one-stage eluate was adjusted to Na 2 After the O concentration is below 180g / L, enter the sorting process to extract aluminum hydroxide; configure Na 2 O concentration 400g / L, the sodium aluminate solution of molecular ratio 60, one section stripping slag is mixed with this sodium aluminate solution by liquid-solid ratio 15, and mixed slurry is placed in autoclave at 300 ℃ of reaction 2h, After the reaction is completed, liquid-solid separation is carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content as high as 87.3...

Embodiment 3

[0034] Configure Na 2 Sodium aluminate solution with an O concentration of 150g / L and a molecular ratio of 2.0, mix the high iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume-to-mass ratio) of 10:1. At this time, the molecular ratio of the ingredients is 1.51. The mixed slurry was reacted at 90°C for 120min, and the liquid-solid separation was carried out while the reaction was hot, and the resulting eluate directly entered the seeding process to extract aluminum hydroxide without adjusting the alkali concentration; configure Na 2 Pure NaOH solution with an O concentration of 300g / L (molecular ratio is infinite), mix a section of the leached slag with the lye at a liquid-solid ratio of 18, and place the mixed slurry in an autoclave at 350°C for 4 hours, and the reaction is over After that, liquid-solid separation was carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content of up to 85.40%; dilute the second-stage e...

technical field

[0001] The invention relates to a method for extracting aluminum and iron from high-iron gibbsite bauxite, in particular to a method for extracting aluminum and iron respectively by two-stage wet stripping in an alkali medium. Background technique

[0002] Aluminum is the second largest metal material after steel. It has a wide range of uses, and its correlation with the national economy is as high as 91%. It is a major pillar industry of the country. As the upstream of the aluminum industry, the output of alumina basic raw materials has been growing steadily. In 2012, my country's alumina output reached 37.72 million tons, accounting for more than 1 / 3 of the world's total output. Bauxite is the main raw material for the production of alumina. However, my country's bauxite reserves only account for 1.5% of the world's reserves. According to the current bauxite consumption per ton of alumina production, the guarantee period for my country's bauxite resources i...

Examples

Embodiment 1

[0030] Configure Na 2 Sodium aluminate solution with an O concentration of 100g / L and a molecular ratio of 3.0, mix the high-iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume mass ratio 7:1), and the molecular ratio of the ingredients is 1.47 at this time. The mixed slurry was reacted at 100°C for 60 minutes, and the liquid-solid separation was carried out while the reaction was hot, and the resulting eluate directly entered the seeding process to extract aluminum hydroxide without adjusting the alkali concentration; configure Na 2 O concentration 300g / L, the sodium aluminate solution of molecular ratio 1.6, one section stripping slag is mixed with this sodium aluminate solution by liquid-solid ratio 20, and mixed slurry is placed in autoclave at 260 ℃ of reaction 1h, After the reaction is completed, liquid-solid separation is carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content of up to 80.45%, dilute the seco...

Embodiment 2

[0032] Configure Na 2 Sodium aluminate solution with an O concentration of 250g / L and a molecular ratio of 4.0, mix the high-iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume-to-mass ratio) of 3:1. At this time, the molecular ratio of the ingredients is 1.74. The mixed slurry was reacted at 130°C for 20min, and the liquid-solid separation was carried out while the reaction was hot, and the obtained one-stage eluate was adjusted to Na 2 After the O concentration is below 180g / L, enter the sorting process to extract aluminum hydroxide; configure Na 2 O concentration 400g / L, the sodium aluminate solution of molecular ratio 60, one section stripping slag is mixed with this sodium aluminate solution by liquid-solid ratio 15, and mixed slurry is placed in autoclave at 300 ℃ of reaction 2h, After the reaction is completed, liquid-solid separation is carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content as high as 87.3...

Embodiment 3

[0034] Configure Na 2 Sodium aluminate solution with an O concentration of 150g / L and a molecular ratio of 2.0, mix the high iron gibbsite ore with the sodium aluminate solution according to the liquid-solid ratio (volume-to-mass ratio) of 10:1. At this time, the molecular ratio of the ingredients is 1.51. The mixed slurry was reacted at 90°C for 120min, and the liquid-solid separation was carried out while the reaction was hot, and the resulting eluate directly entered the seeding process to extract aluminum hydroxide without adjusting the alkali concentration; configure Na 2 Pure NaOH solution with an O concentration of 300g / L (molecular ratio is infinite), mix a section of the leached slag with the lye at a liquid-solid ratio of 18, and place the mixed slurry in an autoclave at 350°C for 4 hours, and the reaction is over After that, liquid-solid separation was carried out while hot to obtain Fe 2 o 3 Iron-rich slag with a content of up to 85.40%; dilute the second-stage e...

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