Method for removing oxalate during production of alumina

A technology for medium oxalate and alumina, which is applied in chemical instruments and methods, preparation of alkali metal aluminate/alumina/aluminum hydroxide, inorganic chemistry, etc., can solve the problem of large heat demand, incomplete removal of sodium oxalate, High energy consumption and other issues, to achieve good filtration performance, improve decomposition output rate, improve product quality and output

Inactive Publication Date: 2019-02-01
GUANGXI HUAYIN ALUMINUM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method requires a lot of heat and consumes a lot of energy.
The invention patent with application number CN201610031882.7 discloses a method for removing sodium oxalate in the production process of alumina. CGM crystallization aids are used to co-crystallize sodium oxalate crystals and sodium carbonate crystals, which reduces consumption, but removes oxalic acid Sodium is not complete

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] A method for removing oxalate in alumina production, adding special crystallization aids and CGM crystallization aids to semen, decomposing, filtering to obtain aluminum hydroxide filter cake, and underflow filtration to obtain oxalate crystals; adjusting the first tank of decomposition The temperature is 58°C; the temperature of the final decomposition tank is 46°C; the added amount of the CGM crystallization aid is 5ppm of the amount of semen, and the amount of the special crystallization aid is 10ppm of the amount of semen; Contains: Oleic Acid 30%, C 8-10 Fatty acid 5%, the rest is water.

[0022] A defoamer is added to the semen, and the defoamer is a silicone defoamer. The addition amount of described antifoaming agent is 20ppm of semen amount.

Embodiment 2

[0024] A method for removing oxalate in alumina production, adding special crystallization aids and CGM crystallization aids to semen, decomposing, filtering to obtain aluminum hydroxide filter cake, and underflow filtration to obtain oxalate crystals; adjusting the first tank of decomposition The temperature is 56°C; the temperature of the final decomposition tank is 45°C; the added amount of the CGM crystallization aid is 3ppm of the amount of semen, and the amount of the special crystallization aid is 30ppm of the amount of semen; Contains: Oleic Acid 20%, C 8-10 Fatty acid 3%, the rest is water.

[0025] The C 8-10 The fatty acids are caprylic acid and capric acid in a mass ratio of 1:1. A defoamer is added to the semen, and the defoamer is a silicone defoamer. The addition amount of described antifoaming agent is 50ppm of semen amount.

Embodiment 3

[0027] A method for removing oxalate in alumina production, adding special crystallization aids and CGM crystallization aids to semen, decomposing, filtering to obtain aluminum hydroxide filter cake, and underflow filtration to obtain oxalate crystals; adjusting the first tank of decomposition The temperature is 62°C; the temperature of the final decomposition tank is 49°C; the added amount of the CGM crystallization aid is 25ppm of the semen amount, and the added amount of the special crystallization aid is 5ppm of the semen amount; Contains: Oleic Acid 10%, C 8-10 Fatty acid 1%, the rest is water.

[0028] The C 8-10 The fatty acids are caprylic acid and capric acid in a mass ratio of 3:1. A defoamer is added to the semen, and the defoamer is a silicone defoamer. The addition amount of described antifoaming agent is 10ppm of semen amount.

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PUM

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Abstract

The invention provides a method for removing oxalate during alumina production and relates to the technical field of alumina production. The method specifically includes: adding a special crystallizing aid and a CGM crystallizing aid into essential oil, decomposing, filtering to obtain an aluminum hydroxide filter cake, and filtering underflow to obtain oxalate crystal; adjusting decomposing headtank temperature to 56-62 DEG C and decomposing tail tank temperature to 45-49 DEG C, wherein adding amount of the CGM crystallizing aid is 0-25ppm of essential liquid amount, adding amount of the special crystallizing aid is 5-30ppm of the essential liquid amount, and the special crystallizing aid comprises, by mass, 10-30% of oleic acid, 1-5% of C8-10 fatty acid and the balance of water. By adding the special crystallizing aid combined with the CGM crystallizing aid, oxalate is stably precipitated in a spherical form, the head tank temperature and the tail tank temperature are adjusted downwards to lower concentration of oxalate in a solution, and decomposition yield is increased.

Description

technical field [0001] The invention relates to the technical field of alumina production, in particular to a method for removing oxalate in alumina production. Background technique [0002] At present, more than 80% of the alumina in my country is produced by the Bayer process. The bauxite in my country is mainly diaspore, and the content of organic carbon is 0.05% to 0.1%. Organic matter and a small amount of organic matter brought in by flocculants, crystallization aids, dehydrating agents, etc. added during the Bayer alumina production process can be decomposed to form sodium oxalate, sodium carbonate and other low-molecular sodium salts as the mother liquor circulates in the process compound. When the concentration of oxalate reaches a certain level, it will cause harm to the production of alumina, make it difficult to settle the red mud dissolved by alumina, and bring about many problems such as the decline in the quality of seed decomposition products. [0003] The me...

Claims

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Application Information

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IPC IPC(8): C01F7/14
CPCC01F7/141
Inventor 刘孟端张观玉陈中源黄喜进张庚民程好德覃卫东韦忠平吴俊池李爱龙梁恩铭李成添韦振权覃伟祥罗付洪王庆刚
Owner GUANGXI HUAYIN ALUMINUM
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