JPS6020080A - Method of executing amorphous refractory containing substance easy to be oxidized to kiln - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for high temperature spraying of monolithic refractories for repairing refractories such as molten metal containers.

When constructing monolithic refractories as repair materials for molten metal containers, in order to improve the durability and adhesion of the monolithic refractories, high oxides such as A and combustible materials such as C are used. It is known how to mix things.

When spraying monolithic refractories containing these high oxides onto the walls of a kiln containing molten metal at high temperatures, the walls of the construction furnace may oxidize or smoke due to the high oxides. This makes construction difficult because it becomes invisible. Also,
Since the above-mentioned high oxides are oxidized before being sprayed, their original functions cannot be achieved, resulting in a decrease in the durability and adhesive strength of the installed refractories. To solve this problem, efforts have been made to improve refractories, such as coating the surface with high oxides to prevent oxidation, but in many cases they are not sufficiently effective. This also destroys the properties of the high oxide as a binder,
It becomes difficult to achieve the original purpose.

Furthermore, in order to increase the rate of strength development after construction of these monolithic refractories, oxidation heat of high oxides in the material may be required, but it is difficult to adjust the oxidation rate with conventional methods. Oxidation progresses more than necessary, causing the above-mentioned problems.

The present invention aims to solve these problems,
The present invention provides a method of constructing a blower that does not cause the above-mentioned defects.

The gist of the present invention to achieve the above object is that when spraying monolithic refractories containing easily oxidizable materials onto the walls of a kiln at high temperatures, non-oxidizing After introducing gas to replace the air in the furnace and lowering the acid rice potential in the furnace, monolithic refractories are blown onto the walls of the furnace (=
A method for constructing a monolithic refractory containing easily oxidizable materials into a kiln, which is characterized by performing J-type construction.

The blowing method of the present invention will be described below with reference to an example implemented in a converter. FIG. 1 shows an example in which the method of the present invention is applied to a top-bottom blowing converter, and FIG. 2 shows an example in which the method is applied to a top-blowing converter. In the case of the top-bottom blowing converter shown in Fig. ft51, after tilting the converter 5 by 90 degrees, non-oxidizing gas 2 (for example, nitrogen gas) can be blown from the bottom of the converter 5 through the bottom blowing tuyere 4. It is possible. Before spraying refractories, the air inside the converter 5 is replaced with non-oxidizing bottom-blown gas 2 to sufficiently lower the oxygen potential inside the furnace, and then air is not allowed to enter from the furnace opening. Reduce the amount of non-oxidizing gas introduced. Thereafter, the monolithic refractory is sprayed from the nozzle 1 onto the refractory wall in the furnace using a non-oxidizing gas as a carrier gas. In the figure, 6 is a monolithic refractory and a non-oxidizing carrier gas for pumping it. In this case, the spraying may be carried out by mixing water 7 into the material, or may be sprayed without mixing it.The method of the present invention is effective in either case.In the latter case Since water is not mixed, the temperature of the monolithic refractory increases in the furnace and it becomes easily oxidized, so the method of the present invention is particularly effective.

In the top-blowing converter 5a shown in FIG. 2, when trying to replace the air in the furnace with non-oxidizing gas, gas cannot be blown from the bottom of the furnace. For this purpose, a replacement gas introduction nozzle 3 as shown in FIG. 2 is used. In the case of a converter with a small furnace capacity,
For spraying, it is also possible to perform gas replacement by introducing a non-oxidizing gas, which is a carrier gas, into the furnace without introducing the monolithic refractory using the construction nozzle L. The nozzle 3 may be omitted depending on the case. In this case, first, the non-oxidizing gas 8 for replacing the gas in the furnace is introduced into the construction nozzle 1, and then the spraying is switched to the monolithic refractory and its carrier gas. The spraying of monolithic refractories after gas replacement is the same as in the top-bottom blowing converter.

The non-oxidizing gas used for gas replacement in the furnace or as a carrier gas should be selected taking into consideration cost, ease of use as a supply source, safety during construction, safety as a gas, etc. Good, but usually N2. Ar, GO2, etc. are suitable.

The amount of non-oxidizing gas used for gas replacement varies depending on the gas supply method, the shape of the reaction vessel, etc., but it is usually 1 part of the furnace volume.
A range of /10 to 10 times is appropriate.

Once the inside of the furnace has been replaced with non-oxidizing gas, the supply of non-oxidizing scum can usually be sufficiently covered by the carrier gas used for pumping monolithic refractories, but depending on the shape of the container, spraying of monolithic refractories may be carried out during construction. When the oxygen potential inside the kiln increases, it is necessary to replenish the gas through the replacement gas introduction nozzle 3.

By the method of the present invention, monolithic refractories containing easily oxidizable materials can be blown into a kiln without impairing their durability.

Example 2 The process of the invention was carried out in a 50 ton top-bottom blown converter.

N2 gas was used as a non-oxidizing replacement gas.

The amount of N2 gas is approximately 1 times the furnace volume, 25ONrn.
It was carried out using '.

Blowing of monolithic refractories using N2 as a carrier gas (-
I went to Jke. The spraying materials used had the components shown in Table 1 below.

Table 1 Quality of sprayed material Basic powder 85% Graphite 3% Easily oxidizable binder 12% When spraying was carried out using the method of the present invention, there was little combustion of C, and refractories constructed using this method The durability was 1.2 to 3 tτ when this method was not used.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views illustrating an embodiment of the method of the present invention.
The figure is a longitudinal sectional view of a top-blowing converter. l... Spraying is done through a nozzle 2... Non-oxidizing scum 3...
Nozzle for introducing non-oxidizing gas gas 4... Nozzle for introducing non-oxidizing replacement gas 5... Top-bottom blowing converter 5a... Top-blowing converter 6... Monolithic refractory and its carrier gas 7.・
・Water 8...Carrier gas (non-oxidizing gas) Applicant: Kawasaki Steel Corporation Kawasaki Reactor Materials Co., Ltd. Figure 1 Δ' Figure 2-391-1

Claims (1)

[Claims] 1. When spraying monolithic refractories containing high oxides onto the walls of a kiln at high temperatures, non-oxidizing scum is introduced into the kiln to replace the air in the furnace with gas. A method for constructing a monolithic refractory containing high oxides into a kiln, comprising spraying the monolithic refractory onto the furnace wall of the kiln after lowering the oxygen potential in the kiln.