SU111475A1 - Electric furnace - Google Patents

Description

The proposed furnace is designed for the smelting reduction of oxidized ores, concentrates and metal-containing wastes.

A distinctive feature of the proposed furnace is the provision of its reducing coke nozzle, located in the zone of separation of the liquid smelting products and solid charge; This nozzle serves as an element of the combined electric arc and resistance; This embodiment of the furnace provides an intensification of the melting process.

The proposed furnace is shown schematically in the drawing. The vertical shaft / furnace is narrowed downwards, where it has an integrated mine 2, covered with a roof 3 made of refractory lining material; The mine and the mining furnace are enclosed in an iron welded casing, sealed to prevent air from leaking into the furnace.

The vault and walls of the hearth, as well as the lower part of the shaft, which are exposed to the highest temperature, are equipped with caissons 4, which cool the refractory masonry in these places.

In the upper part of the shaft, there are hermetically closed feed openings 5, which allow the charge to be charged while the furnace is separated from the atmosphere.

On both sides of the shaft into the furnace, the current-carrying electrodes 6 are installed through the vault of the mine and burned one in relation to the other in a checkerboard pattern. The entry points and the electrodes themselves are enclosed and the sealing covers 7. The furnace is powered by a three-phase current of the usual industrial frequency. Electrodes by the lower ends are introduced into the mass of hot coke cushion and heated solids, not income to the level of a liquid slag bath.

The resulting melting products are discharged in a liquid state through the tape holes 8 located at different levels of the hearth of the furnace.

Gaseous products of smelting, consisting mainly of CO, CO2, hydrocarbons and water vapor, are drained;: from the furnace through the slit holes.

No. 111475

9 to the collecting duct 10, and from there, using blower II, most of the gas enters the heater 12 and then, in a hot condition, is again sent to the furnace through tuyeres 13, which also supply carbon dioxide to the furnace.

The rest of the gases flow from the blower to the burners of the heater, where it is burned in a mixture with air, thereby raising the temperature, of the gases passing through the heater.

The intake slit openings 9 are located below the upper level of the charge rash, thereby eliminating the removal of dust from the furnace shaft, since the charge layer that is in close proximity to the intake openings is like a filter for gases.

Furm | 13 are located at the level of the coke nozzle in the furnace hearth in such a way that the returning gases are supplied to the furnace zone with the highest temperature.

The proposed electric furnace works on the principle of combined heating by an arc and resistance, for which a reducing coke nozzle is created in it. The electric current, the passage through the heated coke packing and the heated charge layer, forms arcs in the places where the pieces of coke come in contact with each other. In addition, heat- ing occurs due to the passage of electric current through a heated piece-like mixture, which is a resistance.

The combined heating of the furnace ensures the formation of a concentrated high-temperature focus in the furnace, which favorably influences the development of the smelting reduction reaction. The presence of coke packing in the furnace, heated to a much higher temperature than the ore material surrounding it, enhances the intensification of the reduction processes.

Subject invention

A shaft electric furnace for reducing smelting of oxidized ores, concentrates and metal-containing waste, characterized in that, in order to intensify the smelting process, it is equipped with a reducing coke packing located in the zone of separation of liquid smelting products and solid charge and an element of the combined electric heating arc and resistance.