SU922156A1 - Method for steel melting in convertor - Google Patents

Description

I

The invention relates to ferrous metallurgy and can be used in the production of steel in converters with a combined upper and lower purge of metal with oxygen.

There is a known method of steelmaking in converters of bottom blowing, according to which the scrap is preheated by supplying oxygen and liquid fuel from the bottom 1.

The disadvantage of this method is the use of expensive liquid fuels.

The closest to the invention to the technical essence and the achieved result is the method of steel smelting in the converter, including filling scrap, preheating it by supplying fuel and oxygen, pouring iron, blowing oxygen into the shell of the protective medium and from above only with oxygen.

The disadvantage of this method is the low heating rate of scrap due to the limited consumption of gaseous fuel through the slotted channels of the bottom tuyeres.

The aim of the invention is to increase the proportion of scrap in the metal charge and the rate of its heating.

The goal is achieved by the fact that according to the method of steelmaking

Claims (1)

10 8 converter, which includes filling scrap, preheating it by supplying fuel from below and oxygen, pouring iron, blowing metal with oxygen from the bottom in the protective shell and from the top only with oxygen, the fuel is also fed through internal channels of bottom tuyeres, and oxygen is introduced from above in the amount of 2Q 0.8-2.0 stoichiometrically necessary for burning fuel, with eton the thermal power is maintained within 30000-150000 kcal per 1 ton lOMo S MVirf Use during heating of scrap for supplying fuel internal channels of tuyeres through which during the purge period, oxygen is supplied, which allows a considerable increase in the consumption of the fuel, as a result of which the heat capacity required for rapid heating with an increase in its quantity is provided. Example. In a horizontal converter, the lining of which is preheated by a gas-air burner to about a temperature, 600 kg of volume with a bulk weight of about 3 tons / mt is poured. During scrap filling, natural gas is supplied at external channels of bottom tuyeres at a flow rate of 0.4. the supply of natural gas through the internal oxygen channels of the bottom tuyeres with a flow rate f Mumin, transfer the converter to the vertical position, pour 40 kg of lump limestone into the converter through the mouth of the con into the grater, lower it into the converter w tuyere while turning therethrough supplying oxygen in an amount of 12 m7m. n Scrap heating is carried out for minutes, after which a true tuyere is raised. Stops the supply of oxygen through it, converting the converter to a horizontal position. Turn off the flow of natural gas through the internal channels of the bottom tuyeres and reduce the consumption of natural gas through the external channels to 0.3 WMHH. The supply of nitrogen through the internal channels of the bottom tuyeres is included in order to prevent pig iron from entering the channels during the period of its discharge and at the same time flushing sections of pipelines that receive natural gas during heating, and oxygen is supplied during ironing. Pour 900 kg of liquid iron with a temperature of 1255 ° C, the following chemical composition,%: carbon 3.97 silicon, 0.81; manganese, 0.93; phosphorus, 0.085; sulfur, 0; At the end of the casting of iron, the nitrogen supply to the internal channels of the bottom tuyeres is turned off, and oxygen is supplied with them at a rate. 3 mumin, transferring the converter to a vertical position, pour 30 kg of lumpy lime through the throat onto the metal surface of the metal bath, lower the upper lance into the converter with simultaneous switching on of 8 m / min oxygen supply through it. The upper lance is set at 00 mm above the conventional surface of the metal bath. 6 minutes after First, the purge lifts the upper lance, turns off the oxygen supply through it, converts the converter to a horizontal position, turns off the oxygen through the internal channels of the bottom tuyeres and the flow of natural gas through their external channels. Samples of metal, slag are taken, the temperature of the metal is measured. The nitrogen is turned on through the outer and inner channels of the bottom tuyeres and the converter is placed in a vertical position, and the metal is flushed with nitrogen for 20 seconds. The converter is shifted to a horizontal position, shutting off the flow of nitrogen through the inner and outer channels. bottom lances, samples of metal and slag are taken, the temperature of the metal is measured, and the metal is drained from the bottom; The expected economic effect from the introduction due to the increase in the scrap share by 100 kg per 1 ton of steel (about 10 by weight of the metal fill and the reduction of the same amount of pig iron when the price difference of 1 ton of pig iron and 1 ton of scrap is about 15 rubles. less than 1.0 rubles per 1 ton of finished steel .. Claim method of steel smelting in a converter that includes filling scrap, preheating it by supplying fuel and oxygen, pouring iron, blowing metal with oxygen from below in a protective environment shell and from above only with oxygen, different and with teM, then, in order to increase the proportion of scrap in the metallic charge and the heating rate, fuel is also fed through internal channels and bottom tuyeres, and oxygen is introduced from the top 59221566 in the amount of 0.8-2.0 stoichiometric sources of information required for fuel combustion, taken into account during the examination while maintaining thermal power -. 1. For the application of the Federal Republic of Germany, which is within the limits of 30000-150000 kka cells. С 21 С З / З, С 21 С 5Л8, for 1 ton of scrap per minute, published. 06.21.79.