Method for improving quality of low-grade zinc oxide and removing fluorine, chlorine and arsenic in low-grade zinc oxide by reducing and roasting in rotary kiln

A low-grade zinc oxide and rotary kiln technology, applied in the field of arsenic removal, low-grade zinc oxide rotary kiln reduction roasting, defluorination, and dechlorination, can solve problems such as arsenic pollution and poor comprehensiveness

Active Publication Date: 2012-08-15
陈建湘
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example, the arsenic pollution produced in the process of producing zinc salt is serious, etc.
There are also studies on the recovery of individual elements in low-grade zinc oxide, but the comprehensiveness is poor

Method used

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  • Method for improving quality of low-grade zinc oxide and removing fluorine, chlorine and arsenic in low-grade zinc oxide by reducing and roasting in rotary kiln
  • Method for improving quality of low-grade zinc oxide and removing fluorine, chlorine and arsenic in low-grade zinc oxide by reducing and roasting in rotary kiln

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The low-grade zinc oxide raw material contains the following ingredients:

[0021] Zn Pb Fe As F Cl moisture 46.58 18.67 2.53 0.713 0.25 0.27 1.2

[0022] The low-grade zinc oxide raw material is added to the rotary kiln, and roasted under the conditions of high temperature and slight negative pressure in the kiln. The temperature inside the kiln is 900°C, and the temperature at the kiln tail is 550°C. For 1.5 hours, fluorine and chlorine compounds undergo physical and chemical changes, promote the decomposition of lead and zinc fluorine and chlorine compounds into a gaseous state, low-boiling point fluorine and chlorine compounds volatilize, and enter the multi-pipe lead removal system and bag dust collection with furnace gas and lead-containing smoke system and desulfurization tower tail gas treatment system, and the roasted low-level zinc oxide is cooled to the rotary kiln to obtain the finished product.

[0023] The rotary kiln is...

Embodiment 2

[0025] The raw material of low zinc oxide contains the following components: (%)

[0026] Zn Pb Fe As F Cl moisture 40 18.67 2.53 0.713 0.25 0.27 1.2

[0027] The low-grade zinc oxide raw material is added to the rotary kiln, and roasted under the conditions of high temperature and slight negative pressure in the kiln. The temperature inside the kiln is 950°C, the temperature at the end of the kiln is 650°C, the rotary kiln speed is controlled at 1.5 revolutions per minute, and the roasting time is 1 hour, following process is identical with embodiment 1. The rotary kiln is connected to a gas-coal mixed fuel burner, and the gas temperature in the first ring is 210°C.

[0028] The calcined sand produced by the rotary kiln of the above two embodiments is as follows: (%)

[0029] Zn Pb F Cl Zn can be As 1# 68.54 3.26 0.021 0.05 66.52 0.35 2# 68.15 3.46 0.027 0.04 66.84 0.30 average 68.35 3.36 0...

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Abstract

The invention discloses a method for improving the quality of low-grade zinc oxide and removing fluorine, chlorine and arsenic in low-grade zinc oxide by reducing and roasting in a rotary kiln. The method comprises the steps of adding the low-grade zinc oxide into the rotary kiln, roasting the low-grade zinc oxide under high temperature and micro negative pressure condition in the kiln with 900-950 DEG C of kiln temperature and 550-650 DEG C of kiln tail temperature, controlling the rotation speed of the rotary kiln to be 1.5turns / min and controlling the roasting time to be 1-1.5h, enabling a fluorine compound and a chlorine compound to be in physical and chemical changes so as to promote the fluorine compound and the chlorine compound of lead and zinc to be decomposed into gas state, volatilizing low-boiling-point fluorine compound and chlorine compound, enabling the low-boiling-point fluorine compound and chlorine compound to enter a multi-tube zinc removing system, a cloth bag dust collecting system and a desulfurizing tower tail gas processing system so as to remove the low-boiling-point fluorine compound and chlorine compound, cooling the roasted low-grade zinc oxide in the rotary kiln to obtain a finished product. According to the method, the superiorities on the chlorine removing rate, the Zn melting rate and the coal consumption are obvious, nearly one-third coal consumption is reduced; and the elements such as the influence of sulfur-containing elements entrained in coal to the environment and the like can be reduced, and the environment pollution can be lowered greatly.

Description

technical field [0001] The invention relates to a method for reducing and roasting a low-grade zinc oxide rotary kiln to improve quality, defluorinate, dechlorinate and remove arsenic. Background technique [0002] The existing zinc oxide finished products are generally obtained by smelting zinc concentrates through multi-hearth furnaces. The equipment investment is large, and zinc concentrates are required as raw materials, resulting in unfavorable factors such as high production costs. [0003] Low-level zinc oxide is one of the main indium-rich waste residues in the zinc metallurgy industry. The chemical composition of low-level zinc oxide varies greatly with different mineral sources, and generally contains zinc, indium, arsenic, antimony, tin, silver, lead, pot, fluorine, etc. Metals, among which lead, arsenic, antimony, fluorine and other elements are poisonous, easily cause serious pollution to water and soil. [0004] Low-grade zinc oxide contains valuable metals su...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B19/02
Inventor 陈建湘
Owner 陈建湘
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