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Power plant waste instead of milk of lime used in Bayer process for alumina production

A technology of waste materials and alumina, which is applied in the preparation of alkali metal aluminate/alumina/hydroxide, chemical industry, climate change adaptation, etc., and can solve unfavorable energy saving, emission reduction and environmental protection, energy consumption and waste of resources, etc. problems, to achieve the effect of saving manpower, saving sections, and saving operators

Active Publication Date: 2011-11-30
EAST HOPE SANMENXIA ALUMINUM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Based on the calculation of a production enterprise with an annual output of 2 million tons of alumina, 1,500 tons of water is needed for lime digestion every day. In addition, the lime digestion and decomposition tank processes also require about 2,100 kilowatts of electricity per day, resulting in huge energy consumption and resources. Waste, not conducive to energy saving and emission reduction and environmental protection

Method used

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  • Power plant waste instead of milk of lime used in Bayer process for alumina production
  • Power plant waste instead of milk of lime used in Bayer process for alumina production

Examples

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Effect test

Embodiment 1

[0027] A kind of technology that waste material of power plant replaces milk of lime is used in Bayer method to produce alumina, and this method is:

[0028] ① Raw material dissolution: Send 2640 tons of crushed ore and 224 tons of lime to the raw material mill, and add qualified mother liquor for wet grinding to make a slurry with a solid content of 350g / L, and send it to the dissolution process at a flow rate of 450 cubic meters per hour ;

[0029] ② Red mud separation: After the ore pulp is dissolved at a high temperature of 260°C, the obtained slurry is diluted with sedimentation washing liquid and then enters the red mud separation process;

[0030] ③ Fine filtration: the crude sodium aluminate liquid obtained from the separation of red mud enters the leaf filter, and is filtered under the condition of using power plant waste as a filter aid, and sodium aluminate semen is obtained after filtration, wherein the power plant waste is power plant desulfurization Ash slag, el...

Embodiment 2

[0033] A kind of technology that waste material of power plant replaces milk of lime is used in Bayer method to produce alumina, and this method is:

[0034] ① Raw material dissolution: Send 2640 tons of crushed ore and 224 tons of lime to the raw material mill, and add qualified mother liquor for wet grinding to make a slurry with a solid content of 350g / L, and send it to the dissolution process at a flow rate of 450 cubic meters per hour ;

[0035] ② Red mud separation: After the ore pulp is dissolved at a high temperature of 260°C, the obtained slurry is diluted with sedimentation washing liquid and then enters the red mud separation process;

[0036] ③ Fine filtration: the crude sodium aluminate liquid obtained from the separation of red mud enters the leaf filter, and is filtered under the condition of using power plant waste as a filter aid, and sodium aluminate semen is obtained after filtration, wherein the power plant waste is power plant desulfurization Ash slag, el...

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Abstract

The invention relates to a Bayer process for producing alumina by using a waste material in a power plant instead of lime milk. The process comprises steps of red mud separation and fine filtering, wherein a filter aid is added into sodium aluminate coarse liquid obtained after the red mud separation is performed to perform the fine filtering, is a mixture formed by uniformly mixing power plant desulfurization ash, electric dust collection ash powder and boiler ash in a mass ratio of (1-3):(2-7):(3-10), and is added in an amount which is 0.1 to 0.5 percent based on the weight of the sodium aluminate coarse liquid. In the process, the waste material produced by the power plant is used for replacing the conventional filter aid, namely the lime milk, the disruptive innovation is made, the waste material is utilized, investment is not required to be increased, energy saving and emission reducing effects and environment friendliness are achieved, and the production cost of the finished alumina product is effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of waste material treatment produced by power plants, and in particular relates to a power plant waste material used in place of milk of lime [0002] The process of producing alumina by Bayer method is to use power plant desulfurization ash, electric dust collector ash powder and boiler ash to replace the existing lime milk and use it as a filter aid in the fine filtration process. Background technique [0003] The existing Bayer method to produce alumina, the process is generally: the ore is pre-desiliconized, dissolved and red mud sedimentation is separated to obtain red mud and sodium aluminate crude liquid, and the sodium aluminate crude liquid is finely filtered through a leaf filter Sodium aluminate semen is obtained by filtering off the remaining floating matter; then the sodium aluminate semen is cooled and then crystallized with aluminum hydroxide seeds, and finally the crystallized aluminum hydr...

Claims

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Application Information

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IPC IPC(8): C01F7/04
CPCY02A50/2351Y02P20/10
Inventor 潘光和
Owner EAST HOPE SANMENXIA ALUMINUM