SU1666902A1 - Ore-smelting electric-arc furnace - Google Patents

Abstract

The invention relates to the field of electrometallurgy, specifically to the design of the linings of electric arc furnaces. The goal is to improve the power distribution in the furnace bath and increase the durability of the hearth. The partitions between the electrodes 4 are made in the form of rectangular protrusions 6 arranged with equal axial pitch. The height of the protrusions from the center of the furnace grows from 0.4 to 1.2 times the diameter of the electrode. The distance between the protrusions is equal to the length of the protrusion. The protrusions are made of carbon blocks of the bottom 2. By transferring a part of the current to the partitions, the specific power in the crucibles of the furnace increases, the volume of crucibles increases, the charge mix increases, the level of overheating of the melt on the bath lining decreases. 1 hp ff, 2 ill.

Description

(Rig. G

The invention relates to the field of electrometallurgy, specifically to the design of the linings of electric arc furnaces.

The aim of the invention is to improve the distribution of power in the furnace bath and increase the durability of the hearth.

FIG. 1 shows an electric arc furnace, a plan; in fig. 2 shows section A-A in FIG. one.

The electric furnace contains a bath 1 with carbonated lined carbon blocks of the bottom 2 and side walls 3, electrodes 4 immersed in the bath 1 and located in plan along the tops of an equilateral triangle 5. protrusions 6 of carbon material spaced at intervals of 7 on straight 8 passing through the axis of the bath 1 is perpendicular to the sides of an equilateral triangle 5, a tap-hole 9 for the release of the melt 10. The bath 1 is filled with velvet materials 11, on the surface of the side walls 3 there is a non-electrically-curdling layer 12. The 13 The electrodes are electrodes of electrodes, and the position 14 is the walls of the crucibles of the sub-electrode space of the furnace.

Arc ore recovery furnace works as follows.

An electric current passes through the electrodes 4 parallel to the resistance of the arc 13 and electrically conductive walls 14 of the crucibles and successively to the resistance of the melt 10 and the conductive bottom 2. The conductive carbon ledges 6, having the same electric potential as the bottom 2, actually detract from part of the current of the electrodes 4. Since the distance between the ends of the electrodes 4 and the protrusions 6 decreases, the resistance of the walls 14 of the crucibles also decreases, and the length of currents flowing from the ends of the electrodes 4 through the walls 14 of the crucibles, the protrusions 6 and the bottom 2 according to the star scheme, increase, respectively, the effective power of excretion in the crucibles increases. This increases the diameter of the crucibles, expands the reaction zone. which covers almost the entire volume of the bath 1, enclosed between the electrodes 4 in its lower horizons. The increase in power released in crucibles does not lead to excessive concentration, as the total volume of crucibles increases.

An increase in the net power and volume of the crucible (reaction zone) leads to a more intense and uniform descent of the charge, the rate of its melting increases, and, accordingly, the productivity of the furnace.

The increase in the rate of descent of the charge material 11 leads to a decrease in its temperature in the upper horizons, it does not have time to sinter, the electrical resistance of the cold charge

higher, which leads to a further decrease in the interelectrode currents in charge.

The decrease in the total resistance of the bath 1 due to the presence of the projections 6 will be compensated by an increase in the resistance in

0 upper layers of the charge. The diversion of a part of the current to the protrusions 6 and then to the bottom 2, mine melt 10 leads to a decrease in the power released in the melt, will reduce the temperature of the bottom sections 2. located directly below the electrodes 4, which are most susceptible to wear, and prevent the bottom 2 from destruction.

The intervals 7 between the protrusions 6 are necessary to allow the melt 10 to flow from the adjacent electrodes 4 and to release it through one working well 9.

The height of the projections 6 must not exceed the distance from the end of the electrode 4 to the bottom 2. This distance, depending on the type of process (slag, slag-free, etc.), is taken equal to 0.4-1.2 of the diameter of the electrode 4.

0 The protrusions 6 of lesser height are set closer to the center of the bath 1, since with distance from the center of the bath the distance from the electrode 4 to the protrusion 6 in the plan increases, and the resistance of the walls 14 of the crucibles increases accordingly. In these areas of the reaction zone compared with areas located directly in the center of bath 1 within triangle 5, the installation of projections 6 of greater height beyond

0 beyond the triangle 5 not only expands the volume of the reaction zone, but also creates temperature conditions in its peripheral areas for as intensive reduction processes as

5 and in the electrode areas.

As protrusions 6 are removed along straight 8 from the center of bath 1 to its side walls 3, the distance between electrode 4 and protrusions 6 increases. The maximum distance 0 between the electrode 4 and the protrusion 6 should not exceed the distance between the electrode and the carbon side lining. Therefore, it is advisable to limit the location of the projections 6 within the circumference,

5 described around the electrodes 4, and position them apart from each other with equal pitch.

The length of the protrusions 6 and the intervals 7 along the straight 8 is chosen for structural considerations. It is preferable to take the length and width of the protrusions to be 6 times

sizes of standard carbon blocks (550x550 or 400x400 mm) from which the hearth is made. In this case, the formation of the projections is simplified by performing them by extending the individual blocks from the bottom by a desired amount.

Claims (2)

Claim 1. Arc furnace metal recovery furnace containing bath, hearth of carbon blocks, side walls, electrodes, partitions of carbonaceous material, installed between the electrodes, 0 A tap hole, characterized in that, in order to improve the power distribution in the furnace bath and increase the bottom resistance, the partitions are made in the form of rectangular projections with equal axial pitch and increasing height from 0.4 to 1.2 of the electrode diameter from the center of the furnace to the circumference described around the electrode, wherein the distance between the protrusions is equal to the length of the protrusion. 2. Electric furnace. Section 1, that is, so that the projections are made of carbon blocks. eight eleven 12