EA018586B1 - Method for melting ferrosilico-aluminum in ore heating furnace - Google Patents

Abstract

The invention relates to production of ferroalloys, in particular complex ferroalloys, and can be used in ferrous metallurgy. The invention is aimed at enhancing gas permeability of the bed zone between electrodes, excluding charge baking on the furnace mouth. The achieved technical result - reducing power consumption for production of ferrosilico-aluminium by 15-18%, increase of the furnace output by 11-14%.

Description

The invention relates to the production of ferroalloys, in particular complex, and can be used in ferrous metallurgy.

There is a method of increasing the gas permeability of a charge and eliminating its sintering on the top of an ore-thermal furnace (analogue 1) by using high-quality quartzites, for example, the Antonovsky deposit (Golovachev N.P., Privalov O.E., Platonov V.Yu., Takenov T.D. Metallurgical evaluation of quartzite as applied to the smelting of siliceous ferroalloys. Collection of proceedings of the Zh.Abishev Institute of Chemical and Metallurgical Sciences, Almaty, Iskander. 2002. Book 2, pp. 173-178). The disadvantages of the method include the deficit and the high cost of these quartzites.

A known method of increasing the uniformity of the distribution of the gas flow over the cross section of the top by preventing sintering of the charge on the top (analog 2) as a result of rotation of the working space of the furnace using a special mechanism (Korotich V.I., Bratchikov S.G. Metallurgy of ferrous metals. M .: Metallurgy , 1997.S. 217-233). The disadvantages of the method are the complexity of manufacture and high operating costs for the operation of the device for rotating the bath of an ore-thermal furnace.

There is a method of eliminating sintering of the charge on the top of an ore-thermal furnace (prototype) by reducing the furnace power as a result of voltage reduction (Strunsky BM Ore-thermal furnaces. M: Metallurgy, 1972. S. 17-22). The disadvantage of this method is that the smelting of the alloy due to low technical and economic indicators is unprofitable.

The tasks of the present invention are sifting out a small part of the charge (fraction <20 mm) and loading it in an amount of 75% to the periphery of the furnace, which helps to reduce the gas pressure in the volume of the crucible under the electrodes and eliminates the sintering of the charge on the top.

The technical result achieved, which can be obtained using the proposed invention, is as follows:

reduced energy consumption for the smelting of ferrosilicon in the amount of 15-18%; the productivity of the furnace increases by 11-14%.

An essential feature of the proposed method is the uneven distribution of the charge by size over the cross section of the furnace. Distinctive features of the proposed method are the screening of the fines of the charge from the bulk and its loading on the periphery of the furnace in an amount equal to 75%. The rest of the fines are fed near and between the electrodes.

In this case, as a result of the high gas permeability of the layer layer near and between the electrodes, gases do not accumulate in the volume of the crucible and the pressure in it decreases, which eliminates the sintering of the charge on the top.

An example of a specific implementation of the method.

The experiments were carried out on a single-phase ore-thermal electric furnace with a capacity of 200 kW. The furnace had the following parameters, mm: diameter of the melting space - 500; height - 450; the diameter of the graphite electrode is 150. The carbonaceous rock of the Bogatyr section, quartzite, metal shavings and wood chips were used as charge materials (see tab. 1-3).

Table 1. The chemical composition of carbonaceous rock,%

Ash: Carbon: Volatile: 1 Moisture: 49.0-78.1 14.2-34.3 11.9-17.8 1 3.1-6.4

Table 2. Ash composition,%

$ Yu ₂ AB ₂ O ₃ Geo CaO Myo R 62.0-65.8 29.7-32.3 2.11-3.78 0.48-1.02 0.20-0.75 0.05-0.18

Table 3. The chemical composition of quartzites,%

8 South AB ₂ Oz Re ₂ About ₃ CaO Humidity 93,4 3.8 0.9 1.9 2.0

The effect of the distribution of charge materials over the furnace cross section on the furnace productivity is shown in table. 4.

Table 4. The dependence of the productivity of the furnace on the distribution of the charge over its cross section

No. The distribution of the small part of the charge over the cross section of the furnace,% The productivity of the furnace,% one. Periphery Near and between electrodes -0 - 100 92 2. Periphery Near and between electrodes -fifty -fifty one hundred 3. Periphery Near and between electrodes - one hundred -0 115 4. Periphery Near and between electrodes -75 -25 118

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The obtained experimental data (see table. 4) indicates that the maximum furnace productivity in the smelting of ferrosilicon aluminum corresponds to the regime when 75% of the fines are loaded onto the periphery of the furnace.

In the table. Figure 5 presents experimental data on the energy consumption for the smelting of ferrosilicon aluminum, depending on the distribution of the fines of the charge over the cross section of the furnace.

Table 5. The effect of the distribution of the charge over the cross section of the furnace on energy consumption.

No. The distribution of the small part of the charge over the cross section of the furnace,% Power consumption,% one. Periphery Near and between electrodes -0 - 100 111 2. Peripherals Near and between electrodes -50 -50 one hundred 3. Periphery Near and between electrodes -one hundred -0 89 4. Periphery Near and between electrodes -75 -25 86

As follows from the table. 5, the minimum energy consumption corresponds to such a distribution of the charge over the furnace cross section, when 75% of the fines are loaded onto its periphery.

Thus, the maximum productivity of the furnace during the smelting of ferrosilicon aluminum and the minimum energy consumption will be when 75% of the fines of the charge are loaded onto the periphery of the furnace.

Claims (1)

CLAIM The method of smelting ferrosilico-aluminum in the ore-smelting furnace, which includes loading of carbonaceous rock, quartzite, metal shavings and wood chips into the furnace, characterized in that a fraction of <20 mm is sifted from the main mass of the charge and loaded in an amount of 75% to the periphery of the furnace, and the rest is loaded around and between the electrodes.