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Method for Enrichment and Recovery of Zinc Using Rotary Kiln

A rotary kiln and enrichment technology, applied in the direction of rotary drum furnace, process efficiency improvement, furnace, etc., can solve the problems of low zinc oxide content in zinc-containing dust, low metallization rate of materials, and low production capacity of rotary kiln, etc. Achieve the effect of improving heat energy utilization rate, improving recovery rate and reducing sticking

Active Publication Date: 2021-11-23
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantages of this method are: there are problems such as low production capacity of the rotary kiln and easy ring formation, low content of crude zinc oxide in the collected zinc-containing dust, and low dezincification rate.
However, the shortcomings of this method are: there are defects such as low dezincification rate, low metallization rate of the reduced material, and low production capacity of the rotary kiln.

Method used

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  • Method for Enrichment and Recovery of Zinc Using Rotary Kiln
  • Method for Enrichment and Recovery of Zinc Using Rotary Kiln
  • Method for Enrichment and Recovery of Zinc Using Rotary Kiln

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] The raw material is low-grade iron ore, and the method of zinc enrichment and recovery using a rotary kiln:

[0054] S1. Raw material preparation: use anthracite and coke powder with a mass ratio of 1:1 as reduced coal, mix them with iron ore and metallurgical dust to evenly pelletize and dry them, and obtain kiln raw materials with an average particle size distribution of 5-15mm; among them, The ratio of the reduced coal, the iron ore and the metallurgical dust is 25%: 35%: 40%; the ash content in the reduced coal is 8%, and the reflow temperature of the ash is greater than 1300°C .

[0055] S2. Calcination process: preheat the kiln-entry raw material prepared in step S1 to 200°C, and then send it into the kiln tail of the variable-diameter rotary kiln. The filling rate of the variable-diameter rotary kiln is 10%; the input amount of the kiln raw material It is 300t / d; and at the end of the kiln, with a blower pressure of 150KPa, pulverized coal and oxygen-enriched ai...

Embodiment 2-3

[0067] The difference from Example 1 lies in that the concentration of oxygen in the oxygen-enriched air is set differently, and other steps are the same as those in Example 1, which will not be repeated here.

[0068]

[0069] The present invention adopts oxygen-enriched air to carry out combustion-supporting, compared with the conventional air in comparative example 2 (oxygen concentration is 21%), can reduce combustion-supporting gas blowing amount, and then make flue gas emission greatly reduce, soot product (coarse zinc oxide ) grade has been improved. At the same time, due to the increase of oxygen concentration, the combustion rate is also improved, which can enhance the processing capacity of rotary kiln reduction roasting, make the recovery of iron ore sufficient, the recovery grade and recovery rate are improved, and the consumption of fuel is greatly reduced .

Embodiment 4-7

[0071] The difference from Example 1 is that the filling rate of the rotary kiln and the input amount of raw materials into the kiln are set differently, and the other steps are the same as in Example 1, and will not be repeated here.

[0072]

[0073] When the residence time of the material is constant, the increase of the filling rate of the rotary kiln and the input of raw materials into the kiln can increase the output of the rotary kiln, but due to the thickening of the material layer, the movement of the material is restricted, so it is unfavorable for the turning and roasting of the material. If the filling rate and input amount are too small, the production capacity of the equipment will not be effectively utilized, and the production cost will also be increased.

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Abstract

The invention provides a method for enriching and recovering zinc by using a rotary kiln. Send the preheated kiln raw materials into the kiln tail of the variable diameter rotary kiln, and blow coal powder and oxygen-enriched air into the kiln tail to carry out the calcination reaction for 80-100 minutes; The flow direction of the gas is consistent with the movement direction of the raw materials entering the kiln, and they all move from the kiln tail to the kiln head; collect roasted ore, grind ore and magnetically separate to obtain iron concentrate; the flue gas extracted by the exhaust fan is Collection and purification treatment, use the dust collection system to collect zinc-containing dust, mix and granulate it with the kiln raw materials, and obtain the mixed kiln materials, send them to the variable-diameter rotary kiln, and cycle through the calcination process and the zinc-containing dust collection process to achieve Circular enrichment of zinc; when the zinc content in the flue gas reaches more than 10%, directly collect the zinc-containing dust in the flue gas, and use the acid leaching process to recover zinc. The method can effectively improve the recovery rate of iron and zinc, prevent the ring formation of the rotary kiln, and has high efficiency and energy saving.

Description

technical field [0001] The invention relates to the technical field of metallurgy and mineral processing, in particular to a method for enriching and recovering zinc by using a rotary kiln. Background technique [0002] Iron ore is an important raw material in the development of the iron and steel industry and plays an important role in the development of my country's national economy. With the rapid development of my country's iron and steel industry, the demand for iron ore continues to grow. In order to improve the grade and comprehensive recycling rate of iron ore, iron ore usually needs to be calcined and processed. At present, the widely used It is a rotary kiln-magnetic separation separation process based on reduced coal-based direct reduction. The process combines roasting, beneficiation and smelting in one process, eliminating the need for high energy consumption and high pollution processes such as beneficiation, sintering, and pelletizing, while shortening the pro...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B7/02C22B1/24C22B1/216C22B19/20C22B5/10C22B1/243
CPCC22B1/216C22B1/2406C22B1/243C22B5/10C22B7/007C22B7/02C22B19/22Y02P10/20
Inventor 张建良徐润生刘征建王广伟
Owner UNIV OF SCI & TECH BEIJING
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