Harmless and comprehensive utilization method of secondary aluminum dross

A secondary aluminum, harmless technology, applied in the preparation of alkaline earth metal aluminate/alumina/aluminum hydroxide, chloride preparation, fluoride preparation, etc., can solve the problem of high production cost, large energy consumption, electrolysis Reduce the service life of the tank and other problems, and achieve the effects of reducing production costs, wide applicability, and efficient recycling

Inactive Publication Date: 2018-01-09
GUIZHOU BRANCH CHINA ALUMINUM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Chinese patent (CN105018739A) discloses a method for recovering alumina, chloride salts, and fluorine salts from aluminum ash, and Chinese patent (CN103555955B) discloses a method for recycling aluminum ash. The miscellaneous secondary aluminum ash is finally returned to the electrolytic cell, because most of the aluminum in the aluminum ash is α-Al with a good lattice 2 o 3 , its activity is very poor, and the electrolysis process needs to consume a lot of energy, which will cause problems such as increased cell voltage, increased energy consumption, and shortened service life of the electrolytic cell.
[0006] Chinese patent (CN103274436B) discloses a method of producing brown corundum by low-temperature smelting of aluminum ash, and Chinese patent (CN101172635A) discloses a method of using waste aluminum ash to produce calcium aluminate. These methods use aluminum ash instead of bauxite resources to prepare aluminum-containing materials, but there is no effective treatment and recycling of hazardous substances such as nitrogen and chlorine salts in aluminum ash
[0007] Chinese patent (CN104261445B) discloses a method for harmless treatment of aluminum ash and preparation of sandy alumina, Chinese patent (CN105271327A) discloses a method for harmless treatment and recycling of aluminum ash, Chinese patent (CN105347361A) A method for comprehensive utilization and treatment of aluminum ash is disclosed. These methods are to perform harmless treatment on the aluminum ash recovered from metal aluminum, and then use an alkali sintering method to dissolve aluminum oxide in the aluminum ash. These processes have complex processes and high production costs. question

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  • Harmless and comprehensive utilization method of secondary aluminum dross

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Comparison scheme
Effect test

Embodiment 1

[0026] The secondary aluminum ash produced by the aluminum ash recovery metal aluminum is processed by the ash sieving method, which is configured into a slurry according to the liquid-to-solid ratio of 1:1, and the deamination reaction is carried out in a sealed deamination reactor with a reaction temperature of 120°C. The reaction time is 1h, the reacted ammonia gas is condensed to recover ammonia water, the reacted slurry is separated from liquid to solid, and the liquid phase is evaporated and crystallized at 150°C to obtain a mixture of chloride and fluoride salts; separated denitrification aluminum ash solid phase washing , After dehydration and drying, it is mixed with calcium oxide powder (CaO content is 96%) according to the weight ratio of 1:0.3. The melting reaction is carried out at a high temperature of 1300℃ for 4 hours. After the reaction, the aluminum is obtained by cooling, crushing and grinding. Salt cement.

[0027] The nitrogen decomposition rate of the second...

Embodiment 2

[0029] The secondary aluminum ash produced by the aluminum ash recovery by the rotary kiln method is used to prepare a slurry according to the liquid-to-solid ratio of 4:1, and the deamination reaction is carried out with stirring in a sealed deamination reactor. The reaction temperature is 20°C and the reaction time 10h, the reacted ammonia gas absorbs ammonia water with water, the reacted slurry undergoes liquid-solid separation, and the liquid phase is evaporated and crystallized at 120°C to obtain a mixture of chloride and fluoride salts; the separated denitrification aluminum ash is solid-phase washed, dehydrated, After drying, it is mixed with limestone (CaO content is 54%), and the weight ratio is 1:3. The melting reaction is carried out at a high temperature of 1400 ℃ for 3 hours. After the reaction, the pre-melted calcium aluminate is obtained by cooling, crushing and screening treatments. Agent.

[0030] The nitrogen decomposition rate of the secondary aluminum ash in t...

Embodiment 3

[0032] The secondary aluminum ash produced by the aluminum ash recovery by the squeezing cooling method is used to prepare a slurry according to a liquid-to-solid ratio of 6:1, and conduct agitation and deamination reaction in a sealed deamination reactor. The reaction temperature is 90°C and the reaction time 6h, the reacted ammonia vapor is condensed to recover ammonia water, the reacted slurry undergoes liquid-solid separation, and the liquid phase is evaporated and crystallized at 100°C to obtain a mixture of chloride and fluoride; the separated denitrified aluminum ash is washed and dehydrated in solid phase , After drying, it is mixed with calcium carbide slag (CaO content is 62%), and the weight ratio is 1:1.4. The melting reaction is carried out at a high temperature of 1500 ℃ for 2 hours. After the reaction, the pre-melted aluminate is obtained by cooling, crushing and screening. Calcium refining agent.

[0033] The nitride decomposition rate of the secondary aluminum as...

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Abstract

The invention provides a harmless and comprehensive utilization method of secondary aluminum dross and relates to a harmless and comprehensive utilization method of secondary aluminum dross produced in an aluminum dross treating process. The harmless and comprehensive utilization method is characterized in that slurry is prepared from the secondary aluminum dross produced in the aluminum dross treating process and water, a stirring deamination reaction is performed, and ammonia gas formed through the reaction is condensed or absorbed by water; slurry after the reaction is subjected to liquid-solid separation, separated liquid phase is subjected to evaporative crystallization, and a chlorate and fluoride salt mixture is obtained; separated solid phase is used for producing a calcium aluminate material. With adoption of the method, the aluminum dross can be treated harmlessly, useful components in the aluminum dross are recovered efficiently, the harmless secondary aluminum dross can replace high-alumina bauxite for preparing a calcium aluminate product, production cost is reduced greatly, zero-release utilization of the aluminum dross is realized, the process is simple, the operation is convenient, the cost is low, environmental protection is realized, and the method has wide applicability.

Description

Technical field [0001] A method for the harmless and comprehensive utilization of secondary aluminum ash relates to a method for the harmless and comprehensive utilization of secondary aluminum ash generated during the treatment of aluminum ash. Background technique [0002] Aluminum ash is produced by infusible inclusions, additives, and physical and chemical reactions with additives that float on the surface of molten aluminum during the production of electrolytic aluminum, cast aluminum and waste aluminum regeneration. The "National Directory of Hazardous Wastes" (2016 Edition) defines the primary smelting slag produced in the aluminum pyrometallurgical process, the salt slag and scum produced in the electrolytic aluminum process, and the flammable slag produced in the aluminum pyrometallurgical process as Hazardous Waste. [0003] Aluminum ash is a renewable resource, which contains 10% to 80% of aluminum. The domestic recovery of metallic aluminum from aluminum ash is roughly...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01C1/02C01B9/02C01B9/08C01F7/16C04B7/32C04B7/147
CPCY02P40/10
Inventor 刘万超刘中凯和新忠练以诚苏钟杨李学鹏闫琨张朝普孙凤娟张蔓琳雷树喜曹瑞雪
Owner GUIZHOU BRANCH CHINA ALUMINUM IND
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