SU1493854A1 - Hearth of ore-smelting furnace - Google Patents

Abstract

The invention relates to electrometallurgy, specifically to the furnace lining, and can be used in the design and commissioning of carbon hearth ore-reduction furnaces. The aim of the invention is to increase the durability of the hearth coal blocks and the overhaul life of the furnace. Under contains a metal casing, thermal insulation, brickwork, bottom coal blocks with a protective coating. The protective coating is made of two layers: a layer of electrode mass and a layer of thermoanthracite with a particle size of 10–25 mm. The thicknesses of the layers are respectively 0.16 - 0.32 and 0.06 - 0.13 of the height of the bottom blocks. Due to the filling of the hearth gaps when the furnace is heated and the subsequent coking of the electrode mass, the service life of the hearth and furnace is extended by 20-25%. 1 ill., 1 tab.

Description

The invention relates to electrometallurgy, specifically to the lining of the hearth of electric furnaces, and can be used in the design and commissioning of ore recovery furnaces with a carbon hearth.

The aim of the invention is to increase the durability of the hearth coal blocks and the overhaul life of the furnace.

The drawing shows the lining of the ore recovery furnace, a vertical section.

Under the ore-reducing furnace includes a layer of thermoanthracite 1, bottom coal blocks 2, a layer of electrode mass 3, brickwork 4,

metal casing 5, brickwork to the wall 6, heat insulation layer 7, fitting coal blocks 8, outlet 9.

The protective coating over the subframe and coal blocks is made up of two layers: electrode mass 3 and thermoanthracite layer 1 with a particle size of 10-25 mm and a thickness of 0.16-0.32 and 0.06-0.13, respectively, of the block height. A layer of bottom mass 3 above the coal hearth blocks serves to create a binder stock, which, when the furnace is heated, fills all the gaps and slots and all the hearth elements and areas of its joint with the furnace lining.

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When the thickness of this layer is less than 0.16 of the height of the coal blocks (h), the mass rapidly volatilizes, and the upper thin layer is porous and fragile. When the layer thickness is more than 0.32h, a large amount of pyrocarbon is formed when the furnace is heated, which degrades the environment in the workshop, without bringing tangible benefits in strengthening the furnace. The top layer of thermoanthracite serves to protect the liquid electrode mass from burning out. Its size is 10–25 mm due to the need for gas removal during mass pyrolysis. The layer of thermoanthracite less than 0.06h does not completely prevent the mass from oxidation and loses its strength properties, and the layer more than 0, I3h impairs its gas permeability and may lead to the expansion of the layer.

Example. Immediately on the bottom of the casing, a layer of fireclay powder (grain size 2-5 mm) is thickened, usually 35 mm thick. A layer of asbestos 15 mm high is placed on the layer of fireclay powder. 12-15 rows of fireclay bricks (4) are laid over asbestos in such a way that the floor panel (the row of bricks overlaps the seams of the underlying row. Brickwork is made on the plate dry, and the side surfaces are smeared with chamotte flour solution. Brick laying is checked on wind and cord On top of the fireclay masonry, a layer of coke with resin is placed on top of it, on which a carbon base is placed on the end face.

outgoing blocks 2 with 550-550 mm section

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dpina of 1.2-1.5 m. A layer of electrode mass 3 with a height of 250-350 mm, which is covered with a layer of thermoanthracite 100-150 mm, is placed on top of the blocks.

During heat-up {the heat mass 2 d melts and fills all the seams and leakages of the hearth and the bottom walls, and then cokes.

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The effectiveness of the proposed technical solution was established experimentally on a laboratory three-phase ore-reduction furnace with a capacity of 160 kVa.

The table presents the test results of the furnace with the proposed hearth.

The smallest destruction of the hearth when protected by only a layer of electrode mass occurs when the ratio of its layer to the height of the coal blocks is equal to 0.3Z. Further thickening of the layer of the electrode mass almost does not reduce its destruction, but increases the mass consumption and air pollution in the furnace. The location of the anthracite layer above the electrode mass layer reduces its fly away, improves the coking conditions of the liquid mass that has penetrated into the pores and cracks of the coal blocks. The least destruction of the hearth occurs when the ratio of the thickness of the layer of thermoanthracite and the height of the coal blocks is equal to 0.13; with an increase in the height of the layer of thermoanthracite, no improvement in the furnace operation is observed. By reducing the wear of the carbon hearth blocks by 20-25%, the turnaround time of the furnace is increased.

Claims (1)

Invention Formula Under the ore reduction furnace, containing a metal casing, thermal insulation, brickwork, bottom coal blocks with protection} {coating, characterized in that, in order to increase the durability of the bottom coal blocks and the overhaul life of the furnace, the protective coating above the bottom blocks is made of two-layer: from the layer of the electrode mass and the layer of thermoanthracite with a thickness of 10–25 mm, with the thickness of the layers being respectively 0.16–0.32 and 0.06–0.13 of the height of the bottom blocks. Layer ratio Production of hearth after 5 heats relative to the initial level, mm (under the electrode ti) Under the unprotected electrode mass and thermoanthracite Under the protection with a layer of electrode ma, with its ratio to the height of the coal blocks: 0.12 0.16 0.20 0.32 0.36 The same, with a Ratio of 0.32, but with one weight per layer of thermoanthracite at a ratio of its current to the height of the coal blocks: 0.04 0.06 0.10 0.13 0.15 Electripeski1 oven operation mode IfiQ U 60-45 V; I 1500-1600 A. 57 s 68.0 52.0 45.0 42.0 37.0 36.5 25.0 22.0 18.0 11.0 11.0 9 1 J