SU1749282A1 - Process for producing commercial zinc product from metallurgical process dust - Google Patents

Abstract

The use of metallurgy non-ferrous metals, in particular zinc. Essence: the gases produced after the reduction of zinc and iron-containing granules are sucked through a layer of lumpy limestone until the zinc content reaches 5-25%, after which the lime is crushed and fed to the raw zinc-containing dust in an amount of 30-40% from the mass of dust, while in order to clean the dusty gases, a new portion of limestone is supplied. In the granulation of the initial mixture, the diameter of the granules is 1-3 mm.

Description

The invention relates to pyrometallurgy, in particular to methods for producing non-ferrous metals, and can be used in zinc technology.

A known method for producing zinc, which consists in the reduction roasting at 1050 ° C of pellets obtained from the dust and slimes of the blast-furnace and steelmaking productions. The average composition of sublimates,%: 2 WLV. Pb 10.4, Rev. 13.9.

The disadvantages of this method include the high consumption of fuel and energy resources and the production of a commercial product with a low zinc content.

Also known is a method for purifying blast gases and a dry method for extracting zinc from precipitated dust, including a rotary centrifugal air separator and a bag filter in the purification system. The coarse fraction is dropped to the walls of the separator, thin enriched with zinc.

(2.5-5.5%) the fraction is collected in a bag filter.

The disadvantages of this method include the impossibility of processing highly dispersed electric steel-smelting dust of variable composition and the low quality of the product obtained.

As a prototype, a method was chosen for extracting zinc from dusts and sludges of ferrous metallurgy, including mixing blast furnace and converter dusts with iron ore and granulating the mixture to produce 4-8 mm granules. A mixture of pellets with coke breeze enters the Waelz furnace, coke consumption 200-300 kg per 1 g of granules. The gases leaving the kiln pass through a water-cooled stand, a cyclone, a dry electrostatic precipitator, a scrubber and a wet electrostatic precipitator. Zinc recovery in sublimates is 87.4%. The composition of velz oxide,% Zn is 62.4, Pb 2.4, Fe 1..2, C 11.3. Iron grains VI 1

ABOUT

Yu

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The uly are returned to the redistribution of the extraction.

The disadvantages of the method include the low quality of the final product (62.4% Zn), due to the charge particles and coal getting into the ozgons, the increased coke consumption and the decrease in the degree of zinc extraction due to the smaller contact surface of the reacting phases during the firing of the pellets with the coke breeze; the impossibility of processing raw materials of variable composition.

The aim of the invention is to improve the quality of the zinc product and reduce energy consumption.

For this in the method of extracting zinc

from dusts and sludges of ferrous metallurgy enterprises, including mixing and granulation of the initial zinc-containing dust with iron-containing material, recovery of the resulting mixture with a carbonaceous reducing agent, purification of the resulting dust-gas stream with trapping while cooling the vapor-containing product, and returning the iron-containing granules to redoing the extract. gases are sucked through a layer of lumpy limestone until a zinc content of 5-25 is reached, after which limestone is ground They feed and feed to the initial charge of the initial zinc-containing dust in the amount of 30-40% of the mass of dust, while in order to clean the dust-laden gases, a new portion of limestone is supplied. In the granulation of the initial mixture, the diameter of the granules is 1-3 mm.

Distinctive features of the prototype are: ;; i;

adding to the initial charge; an amount of 30–40% of the mass of dust;

cleaning of dusty gases through a layer of lumpy limestone up to the achievement of zinc content in it of 5-25%; -;

return of limestone containing 5–25% Zn to the stock;

granule size 1-3 mm.

The invention is as follows.

1000 g of dust containing from 2 to 20% zinc are mixed with 200-500 g of limestone,

containing 5-25% zinc, 150-450 g of carbonaceous reducing agent and 0-150 g of iron-containing waste. The resulting mixture is granulated on a laboratory granulator to obtain granules with a size of 0.5-4 mm.

The pellets are heated to t 950-1200 ° C for 1 hour in a tube furnace equipped with a cooling and dust-collecting system. Gas cleaning through a layer of lumpy limestone is carried out at t = 600-750 ° C. After two-stage dust collection in

laboratory tissue filter get

Color-containing product. Known to after

grinding is served on the charge of dust.

FORUMAWLAH AND ISLANDS

Claims (2)

1 A method for producing marketed zinc. th product from metallurgical dust; .// Predominantly electrolytic, including. mixing and granulating the original zinc-containing dust with an iron-containing material, recovering the resulting mixture with a carbonaceous reducing agent, sticking the resulting dust-gas stream with trapping, upon cooling, peaks of the zinc-containing product and returning the iron-containing granules to the redistribution of iron extraction, as well as with tea and with , in order to improve the quality of the zinc product and reduce energy consumption, cleaning dusty gases are carried out. by passing them through a layer of lumpy limestone until the zinc content in it is 5-25%. After that, the limestone is crushed and fed to the batch of the original Zinc-containing dust in an amount of 30-40% of the dust mass, while in order to clean the dusty gases, a new Portion of Lime, 2. The method according to claim 1, from l and h of the soup and c. the fact that the granulation is carried out to obtain granules with a size of 1-3 mm. .