RU2366722C2 - Method of steel production and installation for implementation of this method - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method consists in preparation of thermite mixture containing scale, aluminium chips and modifiers, in loading mixture into refractory tank, in activating it with igniting and in reducing reaction producing liquid metal and slag. Also thermite mixture is loaded into the refractory tank continuously in form of supply of a continuous compacted core. The method is implemented at the aggregate consisting of the installation for continuous compaction of the core out of thermite mixture and its supply into a reaction chamber of spherical shape; the chamber consists of a case with two notches arranged at different levels, of a removable cover with a port for receiving the continuous compacted core out of thermite mixture and of an actuator for core ignition. Also installation for continuous compaction is made with reverse supply of the core into the chamber. The invention facilitates continuous supply of materials of thermite core into a zone of reaction.

EFFECT: increased share of reduced iron and increased efficiency of process.

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Description

The invention relates to methods for the recovery of steel from scale and can be used in metallurgy.

The closest in technical essence to the achieved result is a method of continuous direct reduction of iron according to patent US 4701213 A (publ. 20.10.1987), where aluminum is used as a reducing agent in a thermite mixture containing iron oxides. The mixture is ignited and iron is reduced as a result of an exothermic reaction.

The considered method has the following disadvantages. The reduction of iron from a thermite mixture in a loose state is a low-productivity process with a small fraction of reduction of iron, because in a granular medium, there is no close contact between the iron oxides and the reducing agent. In addition, the loose thermite mixture, initially falling on the separation layer of the reagent, is not fully restored, because the reducing agent (aluminum) is actively oxidized, which also reduces the productivity of the process.

These disadvantages are eliminated by the claimed method. In the method for producing steel, which involves preparing a thermite mixture consisting of aluminum oxide scale and modifiers, loading it into a refractory tank, activating it by ignition, and initiating a reduction reaction to form liquid metal and slag, while the thermite mixture is loaded into the refractory tank continuously in as a continuous pressed rod.

New in the claimed method is that the thermite mixture in the refractory container is loaded continuously in the form of a continuous pressed rod.

Since in the inventive method, the thermite mixture is loaded continuously into the refractory container in the form of a continuous extruded rod, the productivity of the process and the proportion of reduced iron increase. Due to the fact that the thermite mixture is continuously loaded in the form of an extruded rod of the thermite mixture with a density higher than the bulk density, tight contact between the reduced iron and the reducing agent is ensured, therefore, the iron from the thermite mixture is restored in a larger volume and the process productivity increases.

The closest in technical essence to the achieved result is a device for continuous direct reduction of iron according to the patent US 4701213 A (publ. 10/20/1987), containing a sealed lined converter, in which the pipe for supplying the thermite mixture is located, in the converter case there are holes for draining formed the result of an exothermic reaction of slag and iron.

The considered device has the following disadvantage. The viscous slag layer formed as a result of the reaction prevents the recovered molten iron from entering the discharge zone.

This disadvantage is eliminated by the claimed device. In a device for producing steel, including an apparatus for continuously pressing a rod from a thermite mixture and supplying it to a spherical reaction chamber, consisting of a body with two notches located at different levels, a removable cover with an opening for supplying a continuous pressed rod from a thermite mixture, with activator for igniting the rod, the installation for continuous pressing is performed with reverse feed the rod into the chamber.

New in the claimed device is that the installation for continuous pressing is performed with a reverse feed of the rod into the chamber.

Due to the fact that the device is equipped with an installation for continuous pressing, configured to reverse feed the termite rod into the chamber, the latter pushes the resulting slag layer, providing a continuous supply of material of the termite rod to the reaction zone.

The claimed method is carried out using the device shown in the drawing. The device comprises a housing 1 of the reaction chamber with an internal cavity made in the form of a sphere (to increase the efficiency of the process), a removable cover 2, a tap hole for downloading slag 3 and a tap hole for downloading metal 4 located below the tap hole for downloading slag 3. A hole 5 is made in the cover 2 for feeding the pressed rod 6 from the pressing device 7, which is configured to reverse to ensure the interruption of the recovery reaction in an emergency. The pressed rod 6 contains a thermite mixture consisting of aluminum powder and scale (Fe ₃ O ₄ ), which contains at least 25% O, 70% Fe and modifiers. As modifiers can be used, for example, to produce steel by chemical composition, the corresponding St45 FS-45 ferrosilicon powder is a fraction of 0.5 mm with a silicon content of 44%, the remaining elements are not more than: S = 0.02%, P = 0.05 %, Al = 2%, Mn = 0.6%, Cr = 0.5%, C = 0.2%. The termite rod 6 in the reaction chamber 1 is ignited by an activator (not shown in the drawing). As an activator of the reaction, an electric arc or a special fuse can be used. The slag 8 resulting from the exothermic reaction is located above the layer of molten metal 9 due to its lower density.

The method of producing steel is as follows. Prepare a thermite mixture containing aluminum chips, scale and modifiers. The thermite mixture from the pressing device 7 in the form of a pressed rod 6 through the hole 5 in the lid 2 is fed into the reaction chamber of the housing 1. The pressed rod 6 in the reaction chamber of the housing 1 is ignited with an activator. The process of steel recovery takes place in the reaction chamber of the housing 1 quickly, sequentially extending to the entire volume of the termite rod 6 located in the reaction chamber of the housing 1, and passes through the reaction:

3Fe ₃ O ₄ + 8Al = 4Al ₂ O ₃ + 9Fe.

In the process of the termite reaction, slag 8 is formed, which floats in full to the surface of the formed metal 9. Slag is continuously downloaded from the reaction chamber of the housing 1 through the groove 3, and the metal through the groove 4. When the thermite rod 1 is lifted from the reaction zone as a result of reverse The recovery process stops.

Thus, the proposed method and device for its implementation allow continuous production of steel of a homogeneous structure without the use of melting furnaces.

Claims (2)

1. A method of producing steel, including preparing a thermite mixture consisting of scale, aluminum chips and modifiers, loading it into a refractory container, activating it by ignition, and initiating a reduction reaction to form liquid metal and slag, while the thermite mixture is loaded into the refractory tank continuously in the form of a continuous pressed rod. 2. A device for producing steel, including an apparatus for continuously pressing a rod from a thermite mixture and feeding it into a spherical reaction chamber, consisting of a body with two tap holes located at different levels, a removable cover with an opening for feeding a continuous pressed rod from a thermite mixture, and with an activator for igniting the rod, while the installation for continuous pressing is performed with reverse supply of the rod into the chamber.

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