RU1837145C - Electric furnace for leaning slags - Google Patents

Description

The invention relates to non-ferrous metallurgy and is intended to deplete liquid converter slags and also autogenous slag in a liquid bath.

The aim of the invention is to increase the recovery of cobalt and other non-ferrous ketalloys in Feinstein during the processing of N single-nickel ores and concentrates by reducing their losses in dump slag.

The drawing shows a diagram of a rectangular electric furnace in which slag can be depleted in three stages.

The electric furnace has three electrodes 1-3 with an increased distance between them to accommodate partitions dividing the melt into three zones. The electric furnace is located on a reinforced concrete foundation, has a frame, a casing, refractory masonry of the hearth 4, walls 5 and arch 6. The refractory masonry of the walls is cooled in the slag area along the stovetop refrigerators. The loading of each zone of the unit with ore, fluxes and a reducing agent is carried out through holes in the roof 7. The initial slag is poured through the window 8 at the end or through the hole in the furnace roof. At the same end of the furnace are bore holes 9 for releasing matte. The dump slag is discharged through slots 10 located in the opposite end of the furnace. The gas can be vented using gas ducts from the upper elevation of the arch at the ends of the furnace.

Between the electrodes, the unit is divided by refractory walls 11 into three zones, essentially into three separate single-phase electric furnaces. The height of the partitions is from the bottom to the maximum melt level. The gas space of all three zones is common.

The partitions are made of refractory bricks and they have holes (channels) located in the zone of separation of slag and matte, through which the matte passed

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flows from the slag end of the furnace to the matte end eo when the matte is released from the unit. and the slag flows from the matte end to the slag sequentially through three depletion zones during the discharge of slag from the unit.

To ensure uninterrupted flow of matte and slag through the channels (holes) in the furnace walls (to prevent freezing of the bottom of the furnace), the ratio of the current to voltage even at the higher voltage steps of the furnace transformer should be at least 125: 1.

The lower part of the partitions located in the matte bath is not cooled, the upper part of the partitions is cooled by copper glide pipes laid in the masonry. The upper section of the holes (channels) for the melt flow lies 65-115 mm below the plane of the lower glide pipe. The lower cut of the holes lies at the level of the junction of the hearth arch with the walls, which ensures the constant presence of the matte bath in each zone of the furnace.

Electric energy is supplied to the electrodes from a single three-phase transformer with a capacity of 15,000 kVA, which ensures the operation of the electrodes in an arc-free mode.

Essentially, an electric furnace combines three single-phase electric furnaces in one casing, the electric load of which is determined by the immersion depth of the electrodes in the slag melt, i.e. by force passing through a given electrode.

The required electrical load depends on the volume of slag processed, as well as the amount of solid charge loaded into each zone, consisting of a mixture of a reducing agent, sour ore and quartz flux.

The common distance between the axes of the electrodes in industrial rectangular electric furnaces of non-ferrous metallurgy

within 2.5-3 diameters of self-sintering electrodes.

8 of the proposed design of the electric furnace, the distance between the axes of the electrodes should be 4 to 6 diameters of the electrodes, for the location between the electrodes of the refractory walls, the proper working conditions of the walls and some increase in the volume of the melt in the furnace.

The design of the partitions dividing the electric furnace into three depletion zones differs significantly from the partitions of the six-electrode furnace.

The upper mark of the electric furnace walls below the upper level of the slag bath and the slag from one zone of the furnace to another zone flows over the crest of the walls, and matte flows through the holes (channels) in the walls located in the matte bath of the furnace. The limited flow of matte through the lower channels worsens the thermal conditions of the channels and partitions.

Claims (1)

The claims An electric slag depletion furnace, comprising a frame, a casing, walls, a vault with an opening for filling slag and bore holes for releasing slag and matte, electrodes of at least one cooled partition placed in the inter-electrode space with the formation of a channel between the bottom and the bottom cut of the partition, this upper section is placed at a possible upper level of molten slag, which means that, in order to increase the efficiency of the process, the furnace is equipped with an additional partition placed in the interelectrode spaces e, the lower sections of the partitions are placed in the slag, the distance between the electrodes is 4-6 diameters of the electrode and the walls of the furnace in the zone of the slag zone are made coffered. 8