SU1571079A1 - Method of repairing converter outlet hole - Google Patents

Abstract

The invention relates to metallurgy, in particular to technological processes for the repair of the lining of metallurgical units. The goal is to increase the service life of the steel outlet and reduce the duration of the repair. The repair method includes the removal of worn refractory coils and parts of the lining around them, the installation of new coils and the filling of the wear zone with a refractory mass. The gaps and the wear zone are filled with a mass consisting of a magnesite powder of a fraction of 0.05–3.0 mm and an aqueous solution of magnesium sulphate, which is supplied from the cavity of the converter in a jet at a speed of 20–30 m / s from a distance of 0.5–0 , 8 distance from the longitudinal axis of the converter to the repaired zone. Refractory mass is fed in three steps: in the amount of 20-30% of the total consumption with a humidity of 20-25%, in an amount of 20-30% with a humidity of 13-18% and in an amount of 40-60% with a humidity of 8-12%. 1 tab.

Description

The invention relates to the field of ferrous metallurgy, in particular to the mechanization of repair work in converter production.

The aim of the invention is to increase the service life of the steel outlet and shorten the repair time.

The refractory mass, consisting of magnesite powder of a fraction of 0.05–3.0 mm and an aqueous solution of magnesium sulphate, is jetted at a speed of 20–30 m / s from a distance of 0.5–0.8 from the longitudinal axis converter to the surface of the gunning zone. It has also been experimentally determined that the maximum resistance of the steel outlet is achieved,

when the refractory mass is supplied in three steps: in the amount of 20-30% of the total consumption and humidity of 20-25%, in the amount of 23-30% with humidity of 13-18% and in the amount of 40-60% with humidity of 8-12%.

When a refractory mass is supplied with a fraction of more than 3.0 mm from a distance of less than 0.5, the rebound of particles of mass from the repaired zone increases from the longitudinal axis of the converter to the surface of the repaired area at a speed of more than 30 m / s, which reduces the density of the coating and increases the consumption of refractory materials.

When the mass is supplied by a fraction less than 0.05 mm from a distance greater than 0.8, the distance from the axis of the cavity to the surface of the shotcrete zone is less than 20 m / s.

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the density of the coating decreases due to the insufficient kinetic energy of the particles of material in the jet, which leads to a decrease in the service life of the steel outlet.

The division of the refractory mass by quantity into three steps with different humidity is determined by the funnel-shaped wear of the lining in the area of the outlet and the extension of the gap between the installed refractory coils and the lining inside the cavity of the converter. A wetter mass of the first portion better fills a small initial gap. Increasing the gap allows a second batch with less moisture to be supplied. Finally, the wear funnel is filled with the largest portion of the mass with the lowest humidity. The batch feed of mass with different humidity allows to perform repairs without voids and with maximum density and shorten the drying time of the refractory mass (repair time).

An excess of free moisture does not destroy the applied coating, since it leaves the lower layers of the coating not upwards, but down towards the flange of the nozzle branch pipe along the path of least resistance. The way down is shorter and open, as when installing a new notch and fixing it, leaks remain, through which moisture leaves.

When the refractory mass is fed in the first batch is less than 20% of the total flow rate with moisture less than 20% or more than 30% of the total flow rate with moisture content greater than 25%, voids are formed in the gap between the refractory coils and the converter lining due to deterioration of the mass flow or liquid release from the mass, which also leads to the formation of voids when the mass dries.

When applying a refractory mass in the second portion less than 20% of the total consumption with humidity less than 13% or more than 30% of the total consumption with humidity more than 18%, respectively, the formation of voids in the gap due to deterioration of fluidity or an increase in the drying time of the refractory mass.

The mass supply in the third portion is less than 40% of the total consumption with moisture less than 8% or more than 60% of the total consumption with moisture more than 12%, respectively, leads to a decrease in coating density due to an increase in mass rebound from the repaired area and an increase in the consumption of refractory materials or an increase in time drying the applied mass.

In the refractory mass magnesite is used as a filler in a fraction of 2-3

mm, each particle of which is surrounded by a solution of ground magnesite with a fraction of 0.05-1.0 mm. Relatively large particles of magnesite interspersed in monolithic

the base is well resistant to erosion from the metal being poured through the steel outlet.

The method is carried out as follows.

0 The converter is installed vertically and the cutting (removal) of the worn out steel outlet is performed. Then new refractory coils, put on a metal mandrel pipe with a flange,

5 is installed in the channel of the outlet to the stop of the flange of the pipe into the flange of the nozzle of the outlet, followed by fixing. After that, the converter is turned down the outlet

0 and the flow of a refractory mass consisting of a magnesite powder of 0.05-0.3 mm and an aqueous solution of magnesium sulphate from the converter cavity into the annular gap between the coils and the lining and into the wear zone in the hole area is carried out at a speed of 25 m / s from a distance of 0.65 from the longitudinal axis of the converter to the surface of the repaired area. The refractory mass is supplied in three steps:

0 in the amount of 25% of the total consumption with a humidity of 22.5%, in the amount of 25% with a humidity of 15.5% and in the amount of 50% with a humidity of 10%. The converter is kept in a turned position until completely dry.

5 refractory mass.

In converters with a capacity of 160 tons (internal lining diameter of 5.5 m), the refractory mass was fed from a distance of 1.8 m, in converters with a capacity of 300 tons (internal diameter of the lining was 6.6 m), the refractory mass was supplied from a distance of 2.4 m

The process of applying refractory coating suites closer to the semi-dry method with wetting dry refractory powder

5 at the front end of the working tube, but the humidity of the resulting refractory mass can vary widely due to a change in the amount of humidifier supplied per unit of time by means of a simple device, for example, a valve combined with a liquid flow meter.

The refractory mass is prepared during the coating process as follows. Separate paths to the mixing chamber, to which the nozzle is docked, dry refractory material and humidifier are supplied. The amount of refractory material delivered per unit of time does not change. The amount of humidifier can me62

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stay within wide limits, providing predetermined moisture intervals for the refractory mass.

The results of testing are presented below (digital data indicate, respectively, the tap hole, heats / duration of repair, min).

Fraction of magnesite powder 45 0.03 mm, jet speed 18 m / s, jet length 49 0.4 distances from the cavity axis to the repair zone, the amount of refractory mass: in the first portion 19% with a humidity of 19%, in the second 19% with 11% humidity, 62% in the network with 6% humidity.

Fraction of magnesite powder 47 3.2 mm, jet velocity 35 m / s, 51 jet length 0.9 distances from the cavity axis to the repair zone, the amount of refractory mass: in the first portion 31% with a humidity of 27%, in the second 31% with humidity of 20%, in aerials of 38% with a humidity of 14%.

The magnesite powder fraction is 58-0.05 mm, the jet velocity is 20 m / s, the jet length is 45 distances from the axis of the cavity to

repair areas, the amount of refractory mass: in the first portion of 20% with a humidity of 20%, in the second 20% with a humidity of 13%, in the third 60% with a humidity of 8%. Fraction of magnesite powder 3.0 mm, jet speed 30 m / s, jet length 0.8 distances from the cavity axis to the repair zone, the amount of refractory mass: in the first portion 30% with a humidity of 25%, in the second 30% with a humidity of 18 %, in the third 40% with a humidity of 12%.

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The method allows increasing the resistance of the steel outlet of the converter, reducing the consumption of refractory materials for repairs, speeding up the process of repairing the hole, as well as increasing the productivity of converters

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Claims (1)

Invention Formula The method of repairing the steel outlet of the converter, including cutting the hole, installing refractory coils in it, filling the gap between the refractory coils and the converter lining and the lining wear zone in the hole area with a refractory mass consisting of magnesite powder and an aqueous solution of magnesium sulphate, characterized by In order to increase the service life of the steel outlet and reduce the duration of the repair, the refractory mass is supplied from the converter cavity from a distance of 0.5-0.8 times Nor from the longitudinal axis of the converter to the surface of the gunning zone, a jet with a speed of 20-30 m / s, while 20-30% of the total consumption of the refractory mass is fed with a humidity of 20-25%, then the next 20-30% of the refractory mass is fed with humidity 13-18%, and the rest of the refractory mass in the amount of 40-60% of its total consumption is served with a humidity of 8-12%, moreover, magnesite powder of a fraction of 0.05-3.0 mm is used in the refractory mass.