Method for removing impurities and synchronously preparing calcium-aluminate-series steel-making desulfurization agent through aluminum ash sintering

A technology of calcium aluminate and desulfurizer, applied in the fields of mineral processing and iron and steel metallurgy, can solve the problems of complex process, secondary pollution and high production cost, and achieve the promotion of improving utilization rate, strengthening oxidative decomposition, and improving the conversion rate of aluminum. Effect

Active Publication Date: 2019-06-25
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects of high production cost, complex process and easy to produce secondary pollution in the comprehensive utilization process of aluminum ash in the prior art, and the production process of the existing calcium aluminate steelmaking desulfurizer Defects such as soil and other aluminum source impurities are difficult to remove. The purpose of the present invention is to provide a method of using aluminum ash as an aluminum source to gradually remove impurity elements by controlling the temperature and atmosphere for high-temperature sintering to simultaneously obtain high-quality calcium aluminate steelmaking desulfurization. In this method, the nitrogen in the aluminum nitride component in the aluminum ash is converted into environmentally harmless nitrogen, so as to avoid secondary environmental pollution caused by the formation of NOx, and at the same time remove sodium chloride, potassium chloride, etc. in the aluminum ash Harmful elements, and convert the aluminum component into calcium aluminate, and prepare a high value-added steelmaking desulfurizer. This method is simple to operate, low in production cost, and environmentally friendly, meeting the requirements of industrial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Using aluminum ash (aluminum content 65.6%, nitrogen content 7.2%, chlorine content 4.6%) of an aluminum smelting plant as raw material, first mix aluminum ash and slaked lime according to the elemental ratio of aluminum calcium 1:1.02, mix the raw materials and press them into diameter 15mm agglomerate; after the agglomerate is fully dried, it is placed in an air atmosphere for one-stage roasting, the roasting temperature is 300°C, and the roasting time is 180min; the second-stage roasting temperature is 800°C, the roasting time is 150min, and the roasting atmosphere is O 2 / (O 2 +N 2 ) = 65%; the three-stage melting and roasting temperature is 1580 ° C, the roasting time is 180 min, and the roasting atmosphere is air; 2 o 3 The main phase (theoretical content of 93.2%) is a desulfurizer product with a melting point of 1425°C, and the removal rates of major harmful elements of nitrogen and chlorine are 99.3% and 98.5% respectively during the preparation process.

Embodiment 2

[0028] Using aluminum ash (aluminum content 65.6%, nitrogen content 7.2%, chlorine content 4.6%) of an aluminum smelting plant as raw material, first mix aluminum ash and limestone (silicon dioxide content less than 1%) according to the ratio of aluminum to calcium elements 1:1.05 Dosing, mixing the raw materials and then pressing them into agglomerates with a diameter of 15mm; after the agglomerates are fully dried, put them in an air atmosphere for a first-stage roasting, the roasting temperature is 500°C, and the roasting time is 120min; the second-stage roasting temperature is 1000°C , the roasting time is 90min, the roasting atmosphere is O 2 / (O 2 +N 2 )=40%; the three-stage melting roasting temperature is 1480°C, the roasting time is 240min, the roasting atmosphere is air; 2 o 3The main phase (theoretical content of 90.2%) is a desulfurizer product with a melting point of 1380°C, and the removal rates of major harmful elements of nitrogen and chlorine are 99.0% and 9...

Embodiment 3

[0030] Using aluminum ash (aluminum content 65.6%, nitrogen content 7.2%, chlorine content 4.6%) of an aluminum smelting plant as raw material, firstly mix aluminum ash and steel slag (silicon dioxide content is less than 1%) according to the ratio of aluminum to calcium elements 1:1.1 Dosing, mixing the raw materials and then pressing them into agglomerates with a diameter of 15mm; after the agglomerates are fully dried, put them in an air atmosphere for one-stage roasting, the roasting temperature is 450°C, and the roasting time is 150min; the second-stage roasting temperature is 900°C , the roasting time is 120min, the roasting atmosphere is O 2 / (O 2 +N 2 )=55%; the three-stage melting roasting temperature is 1600°C, the roasting time is 180min, the roasting atmosphere is air; 2 o 3 The main phase (theoretical content of 90.1%) is a desulfurizer product with a melting point of 1450°C. During the preparation process, the removal rates of the main harmful elements of nitr...

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Abstract

The invention discloses a method for removing impurities and synchronously preparing a calcium-aluminate-series steel-making desulfurization agent through aluminum ash sintering. According to the method, aluminum ash and a calcium-containing raw material are evenly mixed and pressed into agglomerates; the obtained agglomerates are dried and then sequentially placed in an air atmosphere to be subjected to first-section low-temperature roasting, placed in a strong-oxidizing atmosphere to be subjected to second-section intermediate-temperate roasting and placed in an air atmosphere to be subjected to third-section high-temperature melting roasting, roasted products are cooled and crushed, and thus the pre-melted calcium-aluminate-series desulfurization agent taking 12CaO.7Al2O3 as the main phase is obtained. Through the method, industrial waste residue is utilized as a main raw material, the raw material source is wide, the cost is low, the high added value is achieved, operation is easy,the production cost is low, the environmental friendly effect is achieved, and industrial production requirements are met.

Description

technical field [0001] The invention relates to a method for preparing calcium aluminate steelmaking desulfurizer by using aluminum ash, in particular to a method for synchronously preparing calcium aluminate steelmaking desulfurizer by using aluminum ash high-temperature sintering to remove impurity elements, belonging to mineral processing and iron and steel metallurgy field. Background technique [0002] Aluminum ash is aluminum-containing waste slag produced in the process of alumina electrolysis, aluminum processing and waste regeneration. According to incomplete statistics, 30-50kg of aluminum ash will be formed for every ton of electrolytic aluminum produced. The total amount of aluminum ash produced in my country is as high as 100- 2 million tons. Aluminum ash contains 30-70% metal aluminum, which has a very high recovery value. In addition, aluminum ash also contains nitrogen, chlorine, fluorine, potassium, sodium and other impurity elements. Aluminum nitride in al...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F7/16C21C7/064
CPCY02P10/20
Inventor 张元波苏子键姜涛刘会群曹楚天范晓慧李光辉彭志伟饶明军黄柱成郭宇峰杨永斌王嘉涂义康古佛全
Owner CENT SOUTH UNIV
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