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Direct reduction method and system of zinc leaching slag

A zinc leaching slag, direct technology, applied in the field of metallurgy, can solve the problems of large acid consumption, unrecoverable silver, large consumption of refractory materials, etc.

Inactive Publication Date: 2016-11-16
JIANGSU PROVINCE METALLURGICAL DESIGN INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

By leaching the kiln slag again, the acid consumption is huge
In addition, 92-94% zinc, 82-84% lead and about 10% silver can be recovered through fuming volatilization in the rotary kiln, and the volatilization rate of indium is less than 80%.
The advantage of the rotary kiln method is that the volatile recovery rate of lead and zinc is high, but the disadvantages are also very obvious
First of all, the silver recovery effect of the rotary kiln method is very poor, most of the silver cannot be recovered, 70% remains in the volatilized kiln slag, and the recovery rate of further silver selection from the kiln slag is 50-65%, resulting in a large amount of precious metals drain
Secondly, expensive coke is required to process one ton of leached slag, and the consumption of refractory materials is large

Method used

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  • Direct reduction method and system of zinc leaching slag
  • Direct reduction method and system of zinc leaching slag

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] (1) Dry the zinc leaching slag. After drying, the zinc content in the slag is 4.34%, the lead content is 5.11%, the indium content is 380g / t, the silver content is 270g / t, and the iron content is 27%. After drying, it is broken to less than 3mm. The dosage of reduced coal is 27% of dry slag weight, 8% of diatomite and 2% of bentonite are added. (2) Mix the zinc slag, reduced coal, bentonite, and diatomite, add water and mix again, and press the pellets through the molding equipment. The drop strength of the pellets is measured for 6 times, which can basically meet the requirements for the strength of the rotary hearth furnace. (3) After forming, the pellets are dried until the water content is less than 4%, and sent into a direct reduction rotary hearth furnace for reduction roasting. The reduction temperature in the furnace is 1250°C, and the reduction time is 50 minutes. (4) In the metallized pellets obtained in step (3), the zinc content in the pellets is 0.23%, th...

Embodiment 2

[0051] (1) Dry the zinc leaching slag. After drying, the zinc content in the slag is 4.34%, the lead content is 5.11%, the indium content is 380g / t, the silver content is 270g / t, and the iron content is 27%. After drying, it is broken to less than 3mm. The dosage of reduced coal is 27% of dry slag weight, 5% of diatomite and 10% of bentonite are added. (2) Mix zinc slag, reduced coal, bentonite, and diatomite, add water and mix again, and press the ball through the molding equipment. The drop strength of the pellet is determined to be more than 20 times, and the pellet strength is high, which can fully meet the requirements of bottom rotation. Furnace into the furnace strength requirements. (3) After forming, the pellets are dried until the water content is less than 4%, and sent into a direct reduction rotary hearth furnace for reduction roasting. The reduction temperature in the furnace is 1300°C, and the reduction time is 42 minutes. (4) In the metallized pellets obtaine...

Embodiment 3

[0053] (1) Dry the zinc leaching slag. After drying, the zinc content in the slag is 4.34%, the lead content is 5.11%, the indium content is 380g / t, the silver content is 270g / t, and the iron content is 27%. After drying, it is broken to less than 3mm. The dosage of reduced coal is 27% of dry slag weight, 5% of diatomite and 10% of bentonite are added. (2) Mix the zinc slag, reduced coal, bentonite, and diatomite, add water and mix again, and press the ball through the molding equipment. The drop strength of the pellet is determined to be more than 20 times, and the pellet strength is high, which can completely meet the bottom rotation Furnace into the furnace strength requirements. (3) After forming, the pellets are dried until the water content is less than 4%, and sent into a direct reduction rotary hearth furnace for reduction roasting. The reduction temperature in the furnace is 1330°C, and the reduction time is 37 minutes. (4) In the metallized pellets obtained in ste...

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Abstract

The invention discloses a direct reduction method and a system of zinc leaching slag. The direct reduction method comprises the steps of drying the zinc leaching slag, so as to obtain dry zinc leaching slag; crushing the dry zinc leaching slag, so as to obtain zinc leaching slag particles; mixing the zinc leaching slag particles with additives and reduction coal, and forming, so as to obtain pellet materials; performing direct reduction on the pellet materials in a direct reduction rotary hearth furnace, so as to obtain smoke which contains zinc, lead, silver and indium and metallized pellets. According to the method, by using preparation and forming processes, the problem of easiness in melting of the pellets is solved, the direct reduction temperature is effectively increased, and the volatilization of zinc, lead, silver and indium is promoted.

Description

technical field [0001] The invention belongs to the technical field of metallurgy. In particular, the present invention relates to a method and system for the direct reduction of zinc leach slag. Background technique [0002] The large amount of lead and silver slag produced in the zinc hydrometallurgy process generally contains scattered metals, precious metals and other valuable metals. The recovery processes for these metals are generally divided into two types: direct method and indirect method. The direct method uses lead and silver slag as the main raw material, and selects an appropriate process to recover the valuable metals in the slag. [0003] Hydrometallurgy is currently the most widely used method of zinc smelting in the world, and the output of electric zinc produced by this method accounts for about 85% of the total zinc output. Zinc hydrometallurgy includes conventional leaching method, hot acid leaching jarosite method, hot acid leaching hematite method, h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B1/24C22B7/04
CPCC22B1/2406C22B7/001C22B7/04Y02P10/20
Inventor 古明远曹志成薛逊王敏吴佩佩吴道洪
Owner JIANGSU PROVINCE METALLURGICAL DESIGN INST
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