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Method for removing harmful elements in preparation process of iron carbide from sintering dust

A technology of harmful elements and iron carbide, which is applied in the field of solid waste resource treatment, can solve the problems such as the difficulty in efficient utilization of sintering dust, difficulty in efficient recovery of iron resources, and easy pollution of the environment, achieving the effect of high value-added utilization

Inactive Publication Date: 2018-10-19
SUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Wet treatment can better remove valuable metals such as potassium, lead and zinc in sintering dust, but it is difficult to efficiently recover iron resources, and the treatment process consumes a lot of acid and alkali, which is easy to pollute the environment
[0007] Therefore, in the utilization method of sintering dust removal, there is a lack of methods that can effectively remove harmful elements such as lead, zinc, potassium and chlorine while obtaining high-quality iron-containing products. In the process, there is no method to remove lead, zinc, potassium, and chlorine, which makes it difficult to efficiently utilize sintering dust

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] The iron grade of the sinter dust removal ash is 46.20%, and the contents of Pb, Zn, K and Cl are 0.52wt%, 0.042wt%, 6.2wt% and 5.42wt% respectively. The sintering dedusting ash added with 2.5wt% bentonite is prepared into green balls with a diameter of 8-16mm in a disc pelletizer, and after the green balls are dried, they are roasted at 900°C for 15 minutes in an air atmosphere and then heated at a temperature of 650°C. Lower and volume ratio CO:CO 2 :H 2 :H 2 Carburize in a mixed gas of 70:10:17:3 for 180 minutes, and cool the hot ball in nitrogen. After cooling, the pellets are ball milled in a conical ball mill under the condition that the pulp concentration is 50wt%, and the grinding fineness is less than 500 mesh, accounting for 95%. Then the pulp is stirred for 1 hour and then filtered. Magnetic separation in the machine can obtain iron carbide with a grade of 83.2% and an iron recovery rate of 80.1%. The removal rates of Pb, Zn, K and Cl are 98.2%, 88.1%, 99....

Embodiment 2

[0039] The iron grade of the sinter dust removal ash is 49.82%, and the contents of Pb, Zn, K and Cl are 0.35wt%, 0.062wt%, 5.2wt% and 5.2wt% respectively. The sintering dedusting ash added with 2.7wt% bentonite is prepared into green balls with a diameter of 8-10mm in a disc pelletizer, and after the green balls are dried, they are roasted at 950°C for 20 minutes in an air atmosphere and then heated at a temperature of 800°C. Lower and volume ratio CH 4 :H 2 :H 2 O is 60:35:5 in the mixed gas of carburizing for 120min, and the hot ball is cooled in nitrogen. After cooling, the pellets are ball-milled in a conical ball mill under the condition that the pulp concentration is 50wt%, and the grinding fineness is less than 500 mesh, accounting for 99%, and then the pulp is filtered after stirring for 1.5 hours. Magnetic separation in the machine can obtain iron carbide with a grade of 86.2% and an iron recovery rate of 81.5%. The removal rates of Pb, Zn, K and Cl are 99.2%, 89....

Embodiment 3

[0041]The iron grade of the sinter dust removal ash is 41.23%, and the contents of Pb, Zn, K and Cl are 0.72wt%, 0.12wt%, 6.9wt% and 7.42wt% respectively. The sintering dedusting dust added with 1.8wt% bentonite was prepared into green balls with a diameter of 8-10mm in a disc pelletizer, and after the green balls were dried, they were roasted at 1000°C in an air atmosphere for 20 minutes, and then baked at 650°C Temperature and volume ratio CO:CO 2 :H 2 :H 2 Carburize in a mixed gas of 65:15:15:5 for 210 minutes, and cool the hot ball in nitrogen. After cooling, the pellets are ball milled in a conical ball mill under the condition that the pulp concentration is 50wt%, and the grinding fineness is less than 500 mesh, accounting for 98%, and then the pulp is stirred for 1 hour and then filtered. Magnetic separation in the machine can obtain iron carbide with a grade of 82.2% and an iron recovery rate of 77.6%. The removal rates of Pb, Zn, K and Cl are 99.4%, 86.1%, 99.0% an...

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Abstract

The invention discloses a method for removing harmful elements in a preparation process of iron carbide from sintering dust. Sintering dust, a binding agent and a proper amount of water are evenly mixed into a fresh pellet which is roasted into a pellet at an oxidizing atmosphere after being dried, the pellet is carburized in mixed gas of CO, CO2, H2 and H2O or in mixed gas of CH4, H2 and H2O andthen subjected to wet ball grinding after being cooled, obtained pulp is stirred and then filtered, elements such as lead, zinc, potassium and chlorine in the pulp are removed, then wet magnetic separation is conducted, and elements such as lead, zinc and potassium are further removed. Through the method, high-quality iron carbide with high added value can be obtained on the basis that lead, zinc,potassium and chlorine are effectively removed, the filtrate can be used as a raw material for further extraction of lead, zinc and potassium, and high-added-value utilization of sintering dust is achieved.

Description

technical field [0001] The invention belongs to the technical field of solid waste resource treatment, and relates to the solid waste treatment and comprehensive utilization of sintering dust removal ash in the process of ironmaking and steelmaking, and specifically relates to the removal of lead, zinc and potassium in the process of preparing iron carbide from sintering dust removal ash and harmful elements such as chlorine. Background technique [0002] Sintering dust is the dust generated during the sintering process of steel plants. At present, my country produces more than 15 million tons of sintering dust every year. Sintering dust is a secondary iron-containing resource with a large amount of resources. In addition, sintering dust also contains harmful elements such as lead, zinc, potassium and chlorine, which are not conducive to blast furnace smelting, such as heavy metals and alkali metals. The sintering dust not only occupies a large amount of land resources, b...

Claims

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Application Information

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IPC IPC(8): C22B7/02C22B1/243C22B1/02C01B32/914
CPCC01P2006/80C22B1/02C22B1/243C22B7/002C22B7/02C01B32/914Y02P10/20
Inventor 陈栋国宏伟闫炳基章顺虎
Owner SUZHOU UNIV