Method for preparing aluminum oxide from aluminum ash in slag-free manner

A technology of alumina and aluminum ash, applied in chemical instruments and methods, preparation of alkaline earth metal aluminate/alumina/aluminum hydroxide, aluminum compounds, etc., can solve the problems of high energy consumption, influence, complex process, etc. Low corrosion, improved removal efficiency, easy-to-achieve effects

Active Publication Date: 2020-12-18
中铝东南材料院(福建)科技有限公司 +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Although the existing methods can also realize the comprehensive utilization of aluminum ash, there are many problems such as complicated process and high energy consumption, and water immersion is often used in the pretreatment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] A method for preparing alumina by utilizing aluminum ash without slag, comprising the following steps:

[0039] (1-1) According to the mass ratio, chlorine gas: aluminum ash = 0.05:1, chlorine gas is passed into aluminum ash, and nitrogen removal reaction is carried out. The nitrogen removal reaction temperature is 400 ° C, and the reaction time is 3 minutes, and nitrogen removal is completed once;

[0040] (1-2) Pass water vapor into the aluminum ash after nitrogen removal once to remove the remaining nitrogen, fluorine and chlorine. Specifically, pass 200°C steam into the aluminum ash, and the mass ratio of water vapor to aluminum ash is 0.5 : 1, the reaction time is 60min, and in the obtained impurity-removing aluminum ash, more than 80% of nitrogen, fluorine and chlorine are removed.

[0041]Nitrogen, chlorine and fluorine in aluminum ash enter the steam after being removed by water steam, and the steam is condensed to form an adsorption solution containing ammonia,...

Embodiment 2

[0045] A method for preparing alumina by utilizing aluminum ash without slag, comprising the following steps:

[0046] (1-1) According to the mass ratio, chlorine gas: aluminum ash = 0.5:1, the chlorine gas mixture is passed into the aluminum ash, and the nitrogen removal reaction is carried out. The nitrogen removal reaction temperature is 200 ° C, and the reaction time is 10 minutes, and the nitrogen removal is completed once;

[0047] (1-2) Pass water vapor into the aluminum ash after nitrogen removal once to remove the remaining nitrogen, fluorine and chlorine, specifically pass 130°C steam into the aluminum ash, the mass ratio of water vapor to aluminum ash is 3 : 1, the reaction time 15min, more than 80% nitrogen, fluorine and chlorine in the obtained impurity-removing aluminum ash can be removed.

[0048] Nitrogen, chlorine and fluorine in aluminum ash enter the steam after being removed by water steam, and the steam is condensed to form an adsorption solution containin...

Embodiment 3

[0052] A method for preparing alumina by utilizing aluminum ash without slag, comprising the following steps:

[0053] (1-1) According to the mass ratio, chlorine gas: aluminum ash = 1:1, chlorine gas is passed into the aluminum ash, and the nitrogen removal reaction is carried out. The nitrogen removal reaction temperature is 150 ° C, and the reaction time is 20 minutes, and the nitrogen removal is completed once;

[0054] (1-2) Pass water vapor into the aluminum ash after nitrogen removal once to remove the remaining nitrogen, fluorine and chlorine, specifically pass 160°C steam into the aluminum ash, the mass ratio of water vapor to aluminum ash is 2 : 1, the reaction time is 30min, and more than 80% of nitrogen, fluorine and chlorine in the obtained impurity-removing aluminum ash can be removed.

[0055] Nitrogen, chlorine and fluorine in aluminum ash enter the steam after being removed by water steam, and the steam is condensed to form an adsorption solution containing am...

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PUM

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Abstract

The invention discloses a method for preparing aluminum oxide from aluminum ash in a slag-free manner, which comprises the following steps: proportionally introducing chlorine into aluminum ash, controlling the reaction temperature and time, introducing water vapor after completing primary denitrification, removing residual nitrogen, fluorine and chlorine to obtain impurity-removed aluminum ash and adsorption steam, and condensing the adsorption steam to form an adsorption solution; adding a corresponding amount of lime into the adsorption solution, reacting to obtain a defluorination solution, adding SO2 for neutralization to obtain an ammonium sulfate solution, and concentrating the solution to obtain an ammonium sulfate product; adding alkali liquor at a corresponding proportion to conduct alkali dissolution treatment on the impurity-removed aluminum ash, thus preparing a liquid phase and a slag phase; and additionally mixing a Bayer process solution with an alkali solution, and carrying out seed crystal decomposition and roasting to obtain the aluminum oxide product. According to the method, a two-stage steam impurity removal mode is adopted, so that the removal efficiency of nitrogen in the aluminum ash is greatly improved, fluorine residues are effectively removed, the aluminum ash is subjected to impurity removal through alkali dissolution treatment, corrosion to equipment is small, and implementation is easy.

Description

technical field [0001] The invention belongs to the technical field of aluminum ash utilization, and in particular relates to a method for realizing harmless utilization of valuable components in aluminum ash by using steam pretreatment and alkali dissolution technology. Background technique [0002] Aluminum ash is one of the main wastes in the aluminum smelting process. Every ton of primary aluminum / aluminum material will produce 180~290kg of aluminum ash slag, and the annual discharge of millions of tons. Aluminum ash is included in the list of hazardous wastes due to nitrogen, fluorine, chlorine and other reasons. [0003] In recent years, relevant practitioners have carried out a lot of research work on the efficient and high-value utilization of aluminum ash, such as "A method for comprehensive utilization of waste aluminum ash and slag forming blocks, public number : CN109402672A "main steps include: (1) aluminum slag is mixed with binding agent, water and stirred to...

Claims

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Application Information

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IPC IPC(8): C01F7/44C01C1/24C01F7/16
CPCC01F7/441C01C1/24C01F7/162C01P2006/80Y02P10/20
Inventor 谢汉青张廷安陈冰吕国志李秋平张子木豆志河刘燕赵桂铭董翌阳王寓霖赵秋月张伟光
Owner 中铝东南材料院(福建)科技有限公司
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