SU398616A1 - METHOD OF GETTING STEEL IN THE UNIT OF CONTINUOUS ACTION f- ^ G '•' • '' k ^ b ^^, • you - Google Patents

Description

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The invention of OTHOCPITCH is to the field of ferrous metallurgy and can be used in steelmaking in continuous-action aggregates.

A known method of producing steel in a continuous aggregate, comprising a stage of obtaining a carbonaceous semi-product from a melt of iron oxides by reducing them with carbon dissolved in a metal melt when purging it with a dust-gas mixture consisting of carbon-containing materials and 1, and the subsequent refining of the obtained semi-product in separate devices.

In the course of the known process, various technological deviations are possible, as a result of which it does not ensure the production of a given carbon content at the outlet of the aggregate in the steel.

In order to ensure the specified carbon content in steel at the exit from the unit, it is proposed to control the consumption of carbon-containing materials in the dust-gas mixture introduced into the metal melt during the production of the carbon semi-product during the process.

The drawing shows a diagram of the process of steel production in a continuous unit.

In apparatus 1, the production of a carbonaceous semi-product (pig iron) is carried out when loaded with iron oxides in a melting cyclone, in which they melt, flux and partially reduce to iron oxide. The resulting melt of iron oxides flows into a converter, in which there is a metal melt, continuously blown by a dust-gas mixture consisting of carbon-containing materials and oxygen. When a metal melt is purged with a dust-gas mixture, the metal is carburized and heated due to partial combustion of carbon in the blast. By mixing the metal and the melt of iron oxides, the latter is reduced by carbon dissolved in the metal melt.

From the converter, the intermediate product having a predetermined carbon content enters the device 2, which is a flow converter, into which dust-like lime is blown through an inert gas that is immersed in metal} fmu with an inert gas. From apparatus 2 purified from impurities other than carbon, the metal flows into apparatus 3, which is a flow converter, into which oxygen is introduced to decarburize the metal.

A temperature sensor 4 is located between apparatuses 2 and 3. Apparatus 1 has a controller 5 for the consumption of carbon-containing materials in the dust-gas mixture introduced into the metal melt. The decarburization process of the intermediate product is carried out using sensor 6. At the output of the apparatus 3, there is a device 7 for sampling and determining the carbon content in the steel. Sensor 8 has a characteristic that it consumes iron ore concentrate entering the apparatus.

In apparatus 2 during the desulfurization of the precursor the carbon content in it practically does not change, and the temperature of the metal decreases by about 20 ° C. As a result of this, desulfurization of the intermediate product does not introduce significant disturbances to the carbon content control system in the finished steel.

In the installation process, Decarburization in apparatus 3 occurs due to supplying 1 metal of oxygen gas into the vain, the amount of which is automatically maintained by regulator 6, taking into account that the temperature difference before and after apparatus 3 remains at a predetermined level.

If during the sampling the carbon content in the steel will be higher than the specified value, then the supply of coal dust to the apparatus / is reduced, and if below it is increased.

The regulator 5 automatically maintains a predetermined consumption of carbon-containing materials in the dust-gas smoy, and the task of the controller is set automatically or manually depending on the actual carbon content in the steel, which is determined by any known method.

In order to improve the quality of regulation, a signal proportional to the consumption of iron ore concentrate from sensor 8 is additionally introduced into the loop of controller 5.

The required metal temperature is automatically maintained by a separate control system, which is not considered here.

When the unit is in operation, the height of the lining of the apparatus 3 leads to an increase in heat loss.

reducing the temperature of the steel and reducing the temperature drop of the metal before and after the apparatus. The regulator 6} increases the oxygen consumption to increase the temperature difference of the metal to its original value, and an increase in the oxygen consumption leads to a decrease in the carbon content in the steel. This, in turn, leads to a corresponding increase in the supply of carbon-containing materials in the dust-gas mixture.

As the linings wear out in apparatus 5, the oxygen consumption for decarburization increases. The height of the lining of the apparatus / and 2 does not affect the carbon content in steel,

but reduces its temperature. Uncontrolled, rapid, small-scale perturbations in the composition of the metal are damped due to sufficient volumes of apparatus baths. Rapid perturbations of a large amount of metal composition mean an emergency condition of any mechanism - in this situation the operation of the unit must be stopped.

Thus, the proposed automatic control system provides

getting a jet of steel with a given carbon content.

Subject invention

A method of producing steel in a continuous unit, including a stage of obtaining a carbonaceous semi-product from a melt of iron oxides by reducing them with carbon dissolved in a metal melt when purging it with a dust-gas mixture consisting of waste-containing materials and oxygen, and a stage of subsequent refining of the obtained semi-product in separate apparatus characterized in that, in order to ensure a given carbon content in the steel when exiting the unit, the carbon consumption is controlled during the process The materials containing the composition of the dust-gas mixture are introduced into my metal melt at the stage of obtaining a teplastic product.