Method for treating sodium oxalate solid waste residues produced in aluminum oxide production process

A technology of sodium oxalate and solid waste residue, which is applied in the removal of solid waste, chemical instruments and methods, preparation of alkali metal aluminate/alumina/aluminum hydroxide, etc., to achieve high utilization value, simple process and good economy and the effect of environmental value

Active Publication Date: 2021-07-23
马朝扬
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The above methods all fail to fully recycle the sodium oxalate solid waste

Method used

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  • Method for treating sodium oxalate solid waste residues produced in aluminum oxide production process

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Experimental program
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Effect test

Embodiment 1

[0036] A kind of treatment method of sodium oxalate solid waste residue in alumina production process, such as figure 1 As shown, the steps of its technological process are:

[0037] (1) the sodium oxalate solid waste residue separated out by removing sodium oxalate from the mother liquor of Bayer process alumina production is heated and decomposed for 1h under the condition that the temperature is 750°C to obtain a decomposed product, and the sodium oxalate solid waste residue contains sodium oxalate The mass percentage of sodium aluminate is 75%, the mass percentage of sodium aluminate is 1%, and the mass percentage of water is 8%;

[0038] (2) the decomposition product is dissolved under the condition of 45 ℃, the dissolving amount of the decomposition product is the decomposition product that every liter of water adds 380g, obtains filter residue 1 and filtrate 1 (containing sodium carbonate, sodium aluminate and sodium hydroxide after filtration) mixed solution);

[003...

Embodiment 2

[0042] A kind of treatment method of sodium oxalate solid waste residue in alumina production process, such asfigure 1 As shown, the steps of its technological process are:

[0043] (1) The sodium oxalate solid waste residue separated out by removing sodium oxalate from the mother liquor of Bayer process alumina production is heated and decomposed for 2.5h under the condition that the temperature is 500° C. to obtain a decomposed product, and the sodium oxalate solid waste residue contains oxalic acid The mass percentage of sodium is 80%, the mass percentage of sodium aluminate is 6%, and the mass percentage of water is 4%;

[0044] (2) the decomposition product is dissolved under the condition of 40 ℃, the dissolving amount of the decomposition product is the decomposition product that every liter of water adds 500g, obtains filter residue 1 and filtrate 1 (containing sodium carbonate, sodium aluminate and sodium hydroxide after filtration) mixed solution);

[0045] (3) filt...

Embodiment 3

[0049] A kind of treatment method of sodium oxalate solid waste residue in alumina production process, such as figure 1 As shown, the steps of its technological process are:

[0050] (1) the sodium oxalate solid waste residue separated out by removing sodium oxalate from the mother liquor of the alumina production by the Bayer process is heated and decomposed for 1.5h under the condition that the temperature is 650° C. to obtain a decomposed product, and the sodium oxalate solid waste residue contains oxalic acid The mass percentage of sodium is 76%, the mass percentage of sodium aluminate is 4%, and the mass percentage of water is 10%;

[0051] (2) the decomposition product is dissolved under the condition of 35 ℃, the dissolving amount of the decomposition product is the decomposition product that every liter of water adds 450g, obtains filter residue 1 and filtrate 1 (containing sodium carbonate, sodium aluminate and sodium hydroxide after filtration) mixed solution);

[...

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Abstract

The invention provides a method for treating sodium oxalate solid waste residues produced in an aluminum oxide production process, belonging to the technical field of treatment of solid waste residues. The method comprises the following steps: (1) heating and decomposing the sodium oxalate solid waste residues to obtain a decomposition product; (2) dissolving and filtering the decomposition product to obtain filter residues and a filtrate; (3) washing and filtering the filter residues to obtain a washing solution and organic matter ash; and (4) processing and recycling the filtrate. According to the method, the sodium oxalate solid waste residues co-crystallized and separated from sodium aluminate mother liquor are converted and recycled, and obtained materials can be returned to the Bayer causticization process and can also be recycled to obtain sodium carbonate, aluminum hydroxide and sodium bicarbonate products. According to the method, various recovery combinations can be carried out according to actual requirements. According to the method, the sodium oxalate solid waste residues are recycled to the maximum extent, a technological process is simple, and the method has good economic and environmental protection values and has good industrial application prospects.

Description

technical field [0001] The invention belongs to the technical field of solid waste residue treatment, and in particular relates to a method for treating sodium oxalate solid waste residue in an alumina production process. Background technique [0002] At present, more than 95% of my country's alumina production capacity is produced by the Bayer process. Due to the fluctuation of the grade of aluminum ore, organic matter is often contained in the ore. These organic substances are divided into two categories: humic acid and asphalt. The asphalt in bauxite is insoluble in alkaline solution, and all of them are discharged into the production system along with red mud. The organic matter of humic acid reacts with alkali to generate various sodium humates, which are then gradually converted into low molecular weight organic compounds such as sodium oxalate and sodium carbonate. During the circulation process of sodium aluminate solution, sodium oxalate will accumulate rapidly, so...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/14C01D7/10C01D7/07B09B3/00
CPCC01F7/142C01D7/10C01D7/07B09B3/00C01P2006/80B09B3/40Y02P10/20
Inventor 马朝扬
Owner 马朝扬
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