SU1084575A1 - Method of removing accretion in metallurgical furnaces - Google Patents

Abstract

A METHOD FOR REMOVING THE REMOVALS IN METALLURGICAL FURNACES, including melting them during fuel combustion and with fluxing, characterized in that, in order to reduce the cost and speed up the process of removing scalls, the melting of the invents is carried out with a mixture of slag of electric melting materials and patterns, in order to reduce the speed of the removal of scaling, with the contents of the template, with the patterns and patterns, in order to reduce the rate of removal of scraps, melting

Description

oo

ate

O The invention relates to non-ferrous metallurgy and can be used to melt and remove scum in furnaces. There is a known method of removing walling in metallurgical furnaces by reflowing them up with fluxing, which is carried out with an oxygen-oxygen burner in the presence of flux-dolomite, limestone, fluorspar, sandstone in the ratio of SiO2: CaO 0.4-0.5 and additive + 10-20% soda by weight of fluxes. The disadvantage of this method is the high consumption of gas, oxygen and fluxes, as well as the consumption of expensive reagent - soda, in addition, melting requires significant costs. The closest to the present invention is a method of removing walling in metallurgical furnaces, including melting them when burning fuel with a flux feed, which is dried out by burning fuel (natural gas, fuel oil or pulverized coal) while maintaining the nastiry temperature of 1300-1500 ° C supplying an air mixture consisting of sand (SiOj) and air 2. The disadvantages of this method are the low rate of wall melting and the appreciation of the melting process due to the presence of a special installation for preparing the air mixture. The purpose of the invention is to reduce the cost and speed up the process of removing wall accretions. This goal is achieved by the fact that according to the method of removing scaling in metallurgical furnaces, including their melting during fuel combustion and with fluxing, the scaling is led by a mixture of slag from electric melting of lead-containing materials and Veller clinker at a mass ratio of 1: (0.6-0.9 ) and the mixture flow rate of 20-30% by weight has nastily. As slag for electric smelting of lead-containing materials, slag of deboning furnace of rough lead, slags from electric smelting of lead dust of slips, etc. are used. The clinker from velvetsevani zinc cake or slag contains, wt.%: Carbon up to 20, metallic iron up to 15 and oxide (FeO) up to 20, silica SiO, up to 20. In the production of lead, zinc, copper, tin, the nastily formed 20 -40% zinc sulfide (ZnS) having a melting point above 1600 ° C. In the presence of a mixture consisting of slag electrowelting of lead-containing materials and Veltsevka clinker, the refractory zinc sulfide (FeS) interacts with metallic iron clinker in the known ZnS-fFe Zn-fFeS reaction. A part of ferrous oxide (FeO) of slag and clinker forms with iron sulfide (FeS) a low-melting eutectic (FeO-FeS), having a melting point of 950 ° C, and a part reacts with clinker silica., Forms a low-melting eutectic (2FeO "SiO2) s melting point 1180 ° C. In addition, lead sulfide (PbS), which is contained in the wall, interacts with sodium oxide (), which contains lead-containing materials in the slag of electric smelting by the known reaction 3PbS- | 2Naj O 3Pb + + SO2. Freshly isolated sodium sulfide interacts with zinc sulfide in nastily, forms a low-melting eutectic (2ZnS-Na2S) with a melting point of 870 ° C and becomes diffuse. Thus, there is a chemical dissolution of wall accretions. Therefore, the loading of a mixture consisting of slag electrofusion of lead-containing materials and clinker from Velcating zinc cakes or slags is more effective than loading one sand with air, as it allows the furnace to penetrate more quickly in the furnace due to its chemical dissolution and the formation of low-melting eutectic. In addition, when using a mixture consisting of slag and clinker, lead, copper, zinc, and noble metals are also extracted from them. The smelting of sand and sand mixtures, consisting of slag, electrofusion of lead-containing materials and Weltsev clinker, is carried out in chamotte crucibles in an electric furnace at 1300 ° C for 60 minutes. After melting the wax, which is determined by the movement of the fixed stem, the mass of crucible is poured and cooled. From the change in the geometrical dimensions of the nastily during the smelting process and the duration of the experiment, the rate of smelting of the nastily was determined. In the experiments used nastila shaft furnace, having the following chemical composition,%: zinc 23.2; lead 11.0; iron 22.8; copper 3.4; sulfur - 18,8; calcium oxide 4.4; silicon dioxide 7,8. Phase, mineralogical analysis of nastily shows that it consists of the following phases: sphalerite (ZnS), bornite (CUjFeS), galena (PbS), pyrite (FeSa), magnetite (FejO)., And the refractory phase (ZnS) contains 27.5 % Slag of electric melting of the furnace for continuous deboning of the composition has the following chemical composition,%; zinc 2.5, lead 3.8; copper 2.8; calcium oxide 11.0; iron monoxide 27.5; silica 19.4 and sodium oxide 6.3. Clinker from the manufacture of zinc cakes, composition,%: zinc 1,4; lead 0.3; copper 1 iron 29.6 (including metallic iron 13.1), carbon 19.1; calcium oxide 6.4; silicon dioxide 18.8; gold 4.2 g / t, silver 64.4 g / t.

The results of the experiments are given in the table, from which it is clear that the maximum rate of melting of nastily with the same duration (60 min) and temperature (1300 ° C) obtained in experiments No. 7, 8.9, 11 and 12 will be from 1.28 to 1, 36 mm / min-, t., A mixture of slag with clinker with a weight ratio of slag to clinker 1: (0.60, 9) and a mixture consumption of 20-30% of the weight of the nastily.

At the same time, the melting rate of the nastily was 2.8-3.0 times greater than during the melting of the prototype.

Reducing the consumption of a mixture of slag and clinker less than 20% of the weight of nastily (experiments No. 1-5) is impractical because it is not enough for chemical dissolution and therefore the melting rate is low, and the increase in consumption of the mixture more than 30% of the weight of nastily (experiment No. 10) leads to a significant increase in the rate of floating.

Slag / clinker weight ratio with optimal mixture loading (20-30% of

weight of nastily) also affects the rate of melting of nastily.

Reducing the slag / clinker ratio to 1: 0.5 (experiment no. 6) and increasing it to 5 1: 1 (experiment no. 3) also does not give a sig nificant increase in the rate of melting of the nastily, since the melt after melting is viscous. The release of such a melt from the furnace is associated with an increase in the duration of melting, and therefore the rate of melting O has not substantially increased.

The proposed method of removing walling in comparison with the prototype allows reducing the cost of the process by eliminating special devices for preparation, air mixture and speeding up the wall melting process by 2.8-3.0 times, while additionally removing non-ferrous metals (lead, copper, silver, gold) contained in slags of electric smelting of lead-containing materials and clinker, into recoverable metal from the furnace 0.

The expected economic effect from the application of the proposed method of removing wall accretions compared to the baseline will be 0.76 rubles. per 1 ton of zinc.

Table continuation

Claims (1)

METHOD FOR REMOVING SHEARS IN METALLURGICAL FURNACES, including melting them during fuel combustion and supplying fluxes, characterized in that, in order to reduce the cost and speed up the process of removing crusts, the melting of logs is carried out with a mixture of slag of electrosmelting of lead-containing materials in mass and: (0.6-0.9) and the flow rate of the mixture 20-30% of the mass accrued. ABOUT QO hu si Si 12