Red mud harmless comprehensive recycling technology suitable for Bayer process

A technology of Bayer method and red mud, which is applied in the field of silicate, can solve the problem of high alkalinity in red mud, achieve the effect of improving recovery rate and reducing radioactivity

Inactive Publication Date: 2012-06-20
ANHUI UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Due to the high alkalinity and radioactivity of red mud, the application o

Method used

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  • Red mud harmless comprehensive recycling technology suitable for Bayer process
  • Red mud harmless comprehensive recycling technology suitable for Bayer process
  • Red mud harmless comprehensive recycling technology suitable for Bayer process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] The source of red mud in the present invention is Bayer process red mud, and its main chemical composition is: Al 2 o 3 : 22~25%; Si0 2 : 16~19%; Fe 2 0 3 : 32~39%; CaO: 0~2%; Na 2 O:8~13%;TiO 2 :7~9%;

[0052] Such as figure 1 Shown, the technological process of the present embodiment is as follows:

[0053] 1) Removal of free alkali in red mud: Red mud contains a large amount of free alkaline substances, so it has strong alkalinity. Since alkaline red mud will damage the equipment in the subsequent process, it must be removed free base. Therefore, before the red mud enters the separation system, the acidic flue gas from the power plant near the alumina plant is first collected to neutralize the red mud tailings slurry acidically. The pH value is 7.5-9, and it will exist in the red mud in the form of attached liquid. The alumina and sodium oxide in the mud are removed to reduce the alkalinity of the red mud and create conditions for the subsequent utilization ...

Embodiment 2

[0065] Such as figure 2 As shown, based on the same principle and method, for the red mud dealkalization mode, the present invention can replace the red mud dealkalization process in the process of Example 1 with the following process system:

[0066] The red mud slurry from the red mud tailings dam is washed and diluted, and the diluted red mud slurry is centrifugally settled to separate most of the solution after settling, and then the bottom flow after settling is subjected to reverse washing for many times, and the The alumina and sodium oxide present in the red mud in the form of attached liquid are removed to reduce the alkalinity of the red mud and create conditions for subsequent red mud recovery. In this way, the purpose of removing alkaline substances in red mud can also be achieved.

[0067]

Embodiment 3

[0069] Such as image 3 As shown, based on the same principle and method, for the flotation process of red mud, the present invention can replace the red mud flotation process and the dehydration process after flotation in the process of Example 1 with the following process system:

[0070] Minerals with a smaller specific gravity produced after re-election, when the diaspore contained in it (mainly becomes Al 2 o 3 ) is less than 10%, this part of the minerals can be directly dehydrated, that is, the flotation ring is saved, and the minerals with a small specific gravity produced after re-election are subjected to centrifugal dehydration or dehydration by pressure filtration, and the minerals after dewatering are used as products Stored and removed water can be used as circulating water. This can also achieve the purpose of the present invention.

[0071]

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Abstract

The invention discloses a red mud harmless comprehensive recycling technology suitable for a Bayer process. The technology is mainly used for removing alkaline matters in the red mud and selecting a great quantity of iron minerals in the red mud through technical means while separating the radioactive minerals such as zircon, monazite and the like from the red mud at the same time; the separated red mud tailings are used as a large quantity of raw materials for cement processing, brick/tile firing, road building and the like, or used as mine filling materials and the like; the red mud minerals are turned into wealth and sufficiently used; large-scale resource utilization of red mud is realized; and a series of problems in resources and environment and potential safety hazard caused by red mud damming and stacking are fundamentally solved.

Description

technical field [0001] The invention relates to the technical field of silicates, in particular to a harmless comprehensive red mud recycling process suitable for the Bayer process, which is used for all-round treatment of red mud waste generated in the alumina production process. Background technique [0002] At present, red mud is the main waste generated during the production of alumina using bauxite. Due to the relatively high iron content, the residue often looks like red soil, hence the name "red mud". In general, 0.8-1.5 tons of red mud will be produced for every 1 ton of alumina produced. my country is the world's largest producer of alumina and the largest red mud emitter. At present, the accumulated stockpile has reached 200 million tons. With the annual increase of alumina production in my country and the gradual decrease of bauxite grade, the annual production of red mud will continue to increase. [0003] At present, alumina plants mostly use red mud pools (da...

Claims

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Application Information

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IPC IPC(8): B09B3/00B09B5/00
Inventor 焦红光高艳阳涂必训吴金保朱金波闵凡飞王超
Owner ANHUI UNIV OF SCI & TECH
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