Bauxite homogenization device and method

Abstract

A bauxite homogenization device includes a primary and secondary screens, a crusher, and a circulating mother liquor delivery pipeline. The circulating mother liquor delivery pipeline is provided with a feed hopper. The aperture of the primary screen is 20 mm, and the aperture of the secondary screen is 0.5 mm. The feed port of the primary screen is connected to a bauxite source via a first conveyor belt. The oversize material of the primary screen is fed to the crusher via a second conveyor belt, and the undersize material of the primary screen is fed to a refining process via a third conveyor belt. The crusher feeds the secondary screen via a fourth conveyor belt. The oversize material of the secondary screen is fed to the refining process via a fifth conveyor belt, and the undersize material of the secondary screen is fed to the circulating mother liquor delivery pipeline via a feed hopper. The upstream end of the circulating mother liquor delivery pipeline is connected to the circulating mother liquor source, and the downstream end of the circulating mother liquor delivery pipeline is used to connect to the slurry outlet of the refining process. The present invention has a simple structure and is easy to operate. While ensuring the quality of the ore slurry in the downstream process, it can effectively reduce the workload of the downstream process.

Description

Technical Field

[0001] The present invention relates to the field of chemical industry, and in particular to a device and method for homogenizing bauxite. Background Art

[0002] When alumina production enterprises use the Bayer process to produce alumina products, they use bauxite as raw material, which is crushed and mixed with the circulating mother liquor to enter the slurry process to obtain ore slurry.

[0003] Since the purchased bauxite is of uneven size, feeding it directly into the refining process will cause heavy load and severe wear on the refining process, which is not conducive to improving the quality of the ore pulp. Currently, the bauxite is usually crushed before being fed into the refining process. This processing method puts a heavy workload on the crusher and fails to effectively reduce the load of the refining process.

[0004] Therefore, how to effectively reduce the load of the refining process of the alumina production line and effectively improve the quality of the ore slurry is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] One of the purposes of the present invention is to address the deficiencies of the prior art and provide a bauxite homogenization device and method, which has a simple structure and is easy to operate. While ensuring the quality of the ore slurry in the downstream process, it can effectively reduce the workload of the downstream process.

[0006] A second object of the present invention is to provide a method for homogenizing bauxite using the above-mentioned homogenizing device, which has a simple and reliable process and can effectively reduce the workload of downstream processes while improving the quality of the ore slurry in downstream processes.

[0007] The technical solution for achieving one of the purposes of the present invention is: a bauxite homogenization device, comprising a primary screen, a secondary screen, a crusher, and a circulating mother liquor conveying pipeline, a feed funnel being provided on the circulating mother liquor conveying pipeline, the aperture of the primary screen is 20 mm, the aperture of the secondary screen is 0.5 mm, the feed port of the primary screen is connected to the bauxite source through a first conveyor belt, the material above the screen of the primary screen is fed to the crusher via a second conveyor belt, the material below the screen of the primary screen is fed to the refining process via a third conveyor belt, the crusher feeds the secondary screen via a fourth conveyor belt, the material above the screen of the secondary screen is fed to the refining process via a fifth conveyor belt, the material below the screen of the secondary screen is fed to the circulating mother liquor conveying pipeline via a feed funnel, the upstream end of the circulating mother liquor conveying pipeline is connected to the circulating mother liquor source, and the downstream end of the circulating mother liquor conveying pipeline is used to be connected to the slurry outlet end of the refining process.

[0008] The first-level screen and the second-level screen are both vibrating screens.

[0009] The fifth conveyor belt feeds materials to the third conveyor belt.

[0010] The circulating mother liquid conveying pipeline extends obliquely downward.

[0011] The technical solution for achieving the second object of the present invention is: a method for homogenizing bauxite using any of the above-mentioned homogenizing devices, comprising the following steps:

[0012] 1) Bauxite is conveyed to the first-level screen via the first conveyor belt, and after screening, the first-level oversize material and the first-level undersize material are obtained;

[0013] 2) The material above the first screen is transported to the crusher via the second conveyor belt, and the material below the first screen is transported to the refining process via the third conveyor belt as refining raw material;

[0014] 3) The crushed material discharged from the crusher is conveyed to the secondary screen via the fourth conveyor belt, and after screening, the secondary oversize material and the secondary undersize material are obtained;

[0015] 4) The material on the secondary screen is transported to the refining process via the fifth conveyor belt as refining raw material, and the material under the secondary screen enters the circulating mother liquor conveying pipeline through the feed funnel;

[0016] 5) Control the mass ratio of the circulating mother liquid to the secondary screen material in the circulating mother liquid delivery pipeline to be 68 ％ , obtaining a mixed ore slurry, which is mixed with the ore slurry discharged from the grinding process.

[0017] The above technical solution has the following beneficial effects:

[0018] 1. The bauxite homogenization device includes a primary screen, a secondary screen, a crusher, and a circulating mother liquor pipeline. The primary screen is used for preliminary screening and grading of the bauxite, the secondary screen is used for secondary screening and grading of the bauxite, the crusher is used to crush bauxite that fails the initial screening and grading, and the circulating mother liquor pipeline is used to provide a carrier. The circulating mother liquor pipeline is equipped with a feed hopper to collect finer particles of bauxite. The circulating mother liquor is used as a carrier, skipping the refining process and being used directly as slurry. The aperture of the first-level screen is 20 mm, and the aperture of the second-level screen is 0.5 mm. The feed port of the first-level screen is connected to the bauxite source through the first conveyor belt. The material on the first-level screen is fed to the crusher via the second conveyor belt, and the material under the first-level screen is fed to the refining process via the third conveyor belt. That is, after the original bauxite is preliminarily screened and classified by the first-level screen, the bauxite with qualified particle size (less than 20m) is directly sent to the refining process and used as raw material, and the bauxite with larger particle size is sent to the crusher for crushing. The crusher feeds the secondary screen through the fourth conveyor belt, the material on the secondary screen is fed to the refining process through the fifth conveyor belt, and the material under the secondary screen is fed to the circulating mother liquor conveying pipeline through the feed funnel. The bauxite with larger particle size is sent to the crusher for crushing, and the bauxite with larger particle size is crushed into small particle size bauxite. Among them, the bauxite with a particle size greater than 0.5mm after crushing is directly sent to the refining process and used as raw material. The bauxite with a particle size less than 0.5mm after crushing is collected through the feed funnel and sent to the circulating mother liquor conveying pipeline. This can reduce the viscosity of the liquid phase in the refining process and improve the refining efficiency of the refining process. In addition, it can also effectively prevent smaller particles of bauxite from being further ground in the refining process, ensure that the particle size of the bauxite in the slurry is within a reasonable range, and avoid the sedimentation and separation effect of the slurry in the subsequent process due to excessive particle size. The upstream end of the circulating mother liquor conveying pipeline is connected to the circulating mother liquor source, and the downstream end of the circulating mother liquor conveying pipeline is used to be connected to the slurry outlet end of the refining process. The smaller particle size bauxite collected in the circulating mother liquor conveying pipeline uses the circulating mother liquor as a carrier, skips the refining process, and is directly mixed with the mineral slurry obtained in the refining process for use in the downstream process.

[0019] 2. The circulating mother liquor conveying pipeline extends downward at an angle, reducing the risk of small particles of bauxite collected remaining in the circulating mother liquor conveying pipeline, avoiding blockage of the circulating mother liquor conveying pipeline, and ensuring the normal operation of the homogenizing device for a long time.

[0020] 3. The homogenization method of the present invention controls the aperture of the first-level screen to 20 mm and the aperture of the second-level screen to 0.5 mm, so that the particle size of the bauxite entering the grinding process is almost maintained below 20 mm and above 0.5 mm. This particle size range can not only ensure the amount of ore discharged from the mill, but also ensure the qualified ore pulp particle size after grinding, meeting production needs; if the particle size is coarse, the amount of ore discharged will be reduced while ensuring the qualified ore pulp particle size after grinding, and the ore pulp flow rate will be small; if the particle size is fine, the amount of ore discharged will increase, but the qualified ore pulp particle size after grinding will be fine, which will affect the sedimentation and separation effect of the subsequent process. The small-particle bauxite (less than 0.5 mm) obtained by crushing treatment is directly used as a carrier with the circulating mother liquor, and the mass ratio of the circulating mother liquor to the small-particle bauxite is controlled to 68%, so that the mixed ore slurry has the same properties as the grinding slurry.

[0021] The following is a further description with reference to the accompanying drawings and specific implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a connection diagram of the present invention.

[0023] In the accompanying drawings, 1 is a primary screen, 11 is a first conveyor belt, 12 is a second conveyor belt, 13 is a third conveyor belt, 14 is a fourth conveyor belt, 15 is a fifth conveyor belt, 2 is a secondary screen, 3 is a crusher, 4 is a circulating mother liquor conveying pipeline, and 5 is a feed funnel. DETAILED DESCRIPTION

[0024] In the present invention, the bauxite used is Guinea ore, and the circulating mother liquor NK is 185-200 g / L.

[0025] Example 1

[0026] See also Figure 1, is a specific embodiment of a bauxite homogenization device. The bauxite homogenization device includes a primary screen 1, a secondary screen 2, a crusher 3, and a circulating mother liquid conveying pipeline 4. The circulating mother liquid conveying pipeline 4 is provided with a feed funnel 5. The circulating mother liquid conveying pipeline extends in an inclined shape. Specifically, the upstream end of the circulating mother liquid conveying pipeline is located at a high point, and the downstream end of the circulating mother liquid conveying pipeline is located at a low point. The aperture of the primary screen 1 is 20 mm, and the aperture of the secondary screen 2 is 0.5 mm. Both the primary screen and the secondary screen are vibrating screens. The feed port of the primary screen 1 is connected to the bauxite source through a first conveyor belt 11. The material above the screen of the primary screen 1 is fed to the crusher 3 via a second conveyor belt 12, and the material below the screen of the primary screen 1 is fed to the refining process via a third conveyor belt 13. The crusher 3 feeds the secondary screen 2 via the fourth conveyor belt 14. The oversize material of the secondary screen 2 is fed to the refining process via the fifth conveyor belt 15. Specifically, the fifth conveyor belt feeds the third conveyor belt. After mixing, the material is sent to the refining process and mixed with the circulating mother liquor before wet grinding. The undersize material of the secondary screen 2 is fed to the circulating mother liquor delivery pipeline 4 via the feed funnel 5. The upstream end of the circulating mother liquor delivery pipeline 4 is connected to the circulating mother liquor source, and the downstream end of the circulating mother liquor delivery pipeline 4 is used to connect to the pulp outlet of the refining process.

[0027] Example 2

[0028] The method for homogenizing bauxite using the homogenizing device of Example 1 comprises the following steps:

[0029] 1) Bauxite is conveyed to the first-level screen via the first conveyor belt, and after screening, the first-level oversize material and the first-level undersize material are obtained. The flow rate of the first-level oversize material is 882t / h, and the flow rate of the first-level undersize material is 378t / h;

[0030] 2) The material above the first screen is transported to the crusher via the second conveyor belt, and the material below the first screen is transported to the refining process via the third conveyor belt as refining raw material;

[0031] 3) The crushed material discharged from the crusher is conveyed to the secondary screen via the fourth conveyor belt. After screening, the secondary oversize material and the secondary undersize material are obtained. The flow rate of the primary oversize material is 617t / h, and the flow rate of the primary undersize material is 265t / h.

[0032] 4) The material on the secondary screen is transported to the refining process via the fifth conveyor belt as refining raw material, and the material under the secondary screen enters the circulating mother liquor conveying pipeline through the feed funnel;

[0033] 5) The mass ratio of the circulating mother liquid to the secondary undersize material in the circulating mother liquid conveying pipeline is controlled to be 68% to obtain a mixed ore slurry, which is mixed with the ore slurry discharged from the refining process.

[0034] It has been verified that after adopting the homogenization method of the present invention, the maintenance cycle of the grinding process is 8 months, and the obtained ore slurry has the same properties as the ore slurry prepared by the Bayer process.

Claims

1. A bauxite homogenizing device, characterized by: The invention comprises a primary screen (1), a secondary screen (2), a crusher (3), and a circulating mother liquid delivery pipeline (4). The circulating mother liquid delivery pipeline (4) is provided with a feed funnel (5). The aperture of the primary screen (1) is 20 mm, the aperture of the secondary screen (2) is 0.5 mm, The feed port of the first-level screen (1) is connected to the bauxite source via a first conveyor belt (11), the screened material of the first-level screen (1) is fed to the crusher (3) via a second conveyor belt (12), and the screened material of the first-level screen (1) is fed to the refining process via a third conveyor belt (13). The crusher (3) supplies material to the secondary screen (2) via the fourth conveyor belt (14), the material on the secondary screen (2) is supplied to the refining process via the fifth conveyor belt (15), and the material under the secondary screen (2) is supplied to the circulating mother liquor conveying pipeline (4) via the feed funnel (5). The upstream end of the circulating mother liquid delivery pipeline (4) is connected to the circulating mother liquid source, and the downstream end of the circulating mother liquid delivery pipeline (4) is used to be connected to the pulp outlet end of the pulping process.

2. The bauxite homogenizing device according to claim 1, characterized in that: The first-level screen (1) and the second-level screen (2) are both vibrating screens.

3. The bauxite homogenizing device according to claim 1, characterized in that: The fifth conveyor belt (15) feeds materials to the third conveyor belt (13).

4. The bauxite homogenizing device according to claim 1, characterized in that: The circulating mother liquid delivery pipeline (4) extends obliquely downward.

5. A method for homogenizing bauxite using the homogenizing device according to any one of claims 1, 2, and 4, characterized in that: The following steps are involved: 1) Bauxite is transported to the first-level screen via the first conveyor belt, and after screening, the first-level oversize material and the first-level undersize material are obtained; 2) The material above the first screen is transported to the crusher via the second conveyor belt, and the material below the first screen is transported to the refining process via the third conveyor belt as refining raw material; 3) The crushed materials discharged from the crusher are transported to the secondary screen via the fourth conveyor belt, and after screening, the secondary oversize material and the secondary undersize material are obtained; 4) The material on the secondary screen is transported to the refining process via the fifth conveyor belt as refining raw material, and the material under the secondary screen enters the circulating mother liquor conveying pipeline through the feed funnel; 5) The mass ratio of the circulating mother liquor to the secondary undersize material in the circulating mother liquor conveying pipeline is controlled to be 68% to obtain a mixed ore slurry, which is then mixed with the ore slurry discharged from the refining process.

6. A method for homogenizing bauxite using the homogenizing device according to claim 3, characterized in that: The following steps are involved: 1) Bauxite is transported to the first-level screen via the first conveyor belt, and after screening, the first-level oversize material and the first-level undersize material are obtained; 2) The material above the first screen is transported to the crusher via the second conveyor belt, and the material below the first screen is transported to the refining process via the third conveyor belt as refining raw material; 3) The crushed materials discharged from the crusher are transported to the secondary screen via the fourth conveyor belt, and after screening, the secondary oversize material and the secondary undersize material are obtained; 4) The material on the secondary screen is transported to the third conveyor belt via the fifth conveyor belt, and then transported to the refining process by the third conveyor belt as refining raw material. The material under the secondary screen enters the circulating mother liquor conveying pipeline through the feed funnel; 5) The mass ratio of the circulating mother liquor to the secondary undersize material in the circulating mother liquor conveying pipeline is controlled to be 68% to obtain a mixed ore slurry, which is then mixed with the ore slurry discharged from the refining process.

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