RU1836456C - Procedure of metallized pellets production of metallurgical process wastes - Google Patents

Abstract

Use: refers to the production of raw materials in metallurgy. SUBSTANCE: method for producing metallized pellets from metallurgical production wastes, includes pelletizing a zinc and lead ore charge, drying, hardening firing and cooling of the obtained granules on a conveyor machine. According to this invention, zinc and lead are removed from the granules before hardening firing, maintaining the layer at a temperature gradually increasing from 700 ° C at an average speed established by the ratio C - 0 2: V 120 (3-5) - ( deg / min, where C is the total content of zinc and lead in the charge, not exceeding 1.8 abs.%, and with a high content of zinc and lead in the charge, the heating rate is set corresponding to the speed when their content is 1.8 both.%. B3

Description

The invention relates to the production of raw materials in metallurgy, in particular to the integrated processing of polymetallic raw materials to produce separate streams of metallized iron ore pellets, zinc and lead.

The present invention is aimed at increasing the yield of zinc and lead and improving the number of calcined granules. To do this, use the method of producing metallized pellets from waste from metallurgical industries, including pelletizing zinc and lead ore charge, drying, aging to remove zinc and lead from granules, hardening roasting

and cooling the obtained granules on a conveyor machine. According to the claimed method, exposure is carried out at a temperature gradually increasing from 700 ° C at an average speed, established by the ratio:

Juu

Yeo

V 120- (3 + 5)

.0,2

0.1

where C is the total content of zinc and lead in the mixture, not exceeding 1.8 abs.%, and with a higher content of zinc and lead c. charge the heating rate is set to the appropriate speed with their content of 1.8%.

with

Recently, the use of various wastes of metallurgical industries for the production of high-quality pellets, zinc and lead containing powders on serial roasting equipment, in particular, on roasting conveyor machines, has been noticeably developed. The organization of such a production ensures the obtaining of additional, high-quality metallurgical raw materials and the solution of a number of hydro-protective tasks.

The conversion of zinc and lead oxides into steam is carried out by their reduction to a metal in a slightly oxidizing medium with an oxygen content of 0.1-2.0%. On the other hand, reducing roasting of iron ore pellets with a significant carbon content in the charge ensures the production of finished products with a high degree of metallization. The method involves the use of waste from two metallurgical industries - blast furnace and steelmaking. So, blast furnace slurry contains a fairly high amount of carbon (8-20%), but a relatively low content of zinc (up to 1.3%) and lead (up to 0.3%). Steel sludge with a low content of solid fuel (up to 0.3%) contains a high content of zinc (1.8-2.5%) and lead (0.5-1.0%). Therefore, their mixing provides pellets on the one hand with the carbon content required for the process, on the other hand, with a sufficient content of zinc, lead and iron. Additional incorporation of fuel into such a charge is not required.

The process of recovering zinc and lead from the pellets has been allocated to a separate processing zone. In this technological zone, the layer is exposed to conditions gradually increasing from 700 ° C. At temperatures below 700 ° C, the reduction processes of the oxides either do not proceed or proceed at a speed that has no practical value. The upper temperature limit in this zone corresponds to the type of product to be fired, and is usually in the range 1220-1300 ° C.

The average rate of temperature increase in the zone of sublimation of metal into steam is determined by the ratio:

V 120- (3 + 5)

C -0.2 0.1

where C is the total content of zinc and lead in the mixture (abs.%).

The physical meaning of this relationship is as follows. For every

0.1% increase in the total content of zinc and lead in the charge, starting from 0.2%, the rate of increase in the average temperature in the sublimation zone increases from 120 deg / min

at 3 + 5 deg / min,

Complex processing of production waste with separate production of metallized pellets, zinc and lead

it is advisable only when the total content of zinc and lead in the mixture is equal to or greater than 0.2%. With a lower content of zinc and lead in the mixture (less than 0.2%) due to the low intensity of the sublimation process, the degree of

5 extraction of zinc and lead to economically unreasonable limits, or there is an increase in the length of the sublimation section and, as a result, a decrease in the specific productivity of the conveyor

0 cars and suitable for fired pellets.

The maximum rate of increase in the average temperature in the distillation zone should be 120 deg / min. This upper limit is limited on the one hand by the conditions of heat and mass transfer in the layer, on the other hand, by the insufficient residence time of the layer of pellets in the sublimation section and a decrease in the degree of zinc extraction and

0 lead from the charge.

An increase in the content of zinc and lead in the charge from 0.2% for every 0.1% should be accompanied by a decrease in the rate of increase in the average temperature by 3-5 deg / min.

5 Such a decrease in the rate of temperature rise is necessary to increase the duration of sublimation with increasing process intensity (zinc and lead content in the charge). At

By lowering the rate of temperature rise by a lower amount (less than 32 deg / min, for every 0.1% increment in the content of zinc and lead in the charge), the degree of extraction of zinc and lead from the charge decreases. At

5

5

lowering the rate of temperature rise

by a large amount (more than 5 deg / min for every 0.1% increment in the content of zinc and lead in the charge), the degree of extraction of zinc and lead from the charge no longer increases - 0 s, and the yield by metallized pellets due to a decrease in useful area conveyor machine is reduced

In excess of the content of zinc and lead in the charge of 1.8% further

the decrease in the rate of temperature rise is stopped. Otherwise, due to the excessive length of the sublimation section, the overall productivity of the machine, the degree of metallization, and the yield of the calcined pellets are reduced.

:. For the purposes of the invention, zinc and lead granules are used, reinforcing nft, v-u

S.tu; og: t /: - :. Udydyrzhka a layer of pellets and cooling the obtained granules at KGU-Tomd /:,:;; full i is zinc granules and lead machine, from and to and so on. Oh.

Ex 1.:: ;; o; l: ki X POG; TG: P8NNO INCREASING - IN ORDER TO INCREASE THE EXITING OF THE YEAR ROUND, Hnr. i Vc i: r up to maximum temperatures, 5 cents of zinc and lead and quality improvement

P (i -; - ;;: ei-iMf: y re, tslag;: of the invention - fired granules, a slurry osuschost; 1: - ii;.:: S ;;: - any increase increase at gradually increase then Tier: or

-: ;;;.: -: v, -: o Air machines, degree 700 ° С temperature with medium speed; ,about,

and., ::: -,:; :.:; chick l of the seinz. ratio adjustment

n.n.,:;, - nys novanymokhaty pelts. .10, y-120- (3-5). deg / min.

 g; :,.: at l s of the invention where C is the total content of w

Cfivon no / iy ftiiHR metallized lead in a charge not exceeding i.S%

o: -: t,: -; / Moh of metallurgical wastes abs.%, and with a higher content of zinc .;

pomp; .. On-line cooling pelletizing-15 lead in the charge heating rate set l / s: :; 0: ::; : -LG-KEY ORGANIC LARGE-. WIND RELATED SPEED pr SP

t: - :: For a cost recovery of 1.8 abs.%.