JPH05279148A - Sio2-impregnated ceramic burner brick for hot-blast stove - Google Patents

Abstract

PURPOSE:To improve the acid resistance (resistance to reaction with SO3 gas) by impregnating refractory brick with a specific solution containing SiO2, drying the impregnated brick and forming an SiO2 film in a matrix part of the refractory brick. CONSTITUTION:The objective refractory brick is obtained by impregnating refractory brick with a solution, containing SiO2 and composed of one or more of a colloidal solution of silicic acid, a silicic acid ester solution, a potassium silicate solution and a lithium silicate solution and forming an SiO2 film in a matrix part of the refractory brick. A silicic acid ester solution of ethyl orthosilicate containing 40wt.% SiO2 solid content, a solution of methyl orthosilicate containing 40wt.% SiO2 solid content, etc., are exemplified as the SiO2 component source. The reaction with SO3 gas is suppressed with the ceramic burner brick for a hot-blast stove by impregnating treatment with the SiO2 and embrittlement and damage can be prevented. The useful life of the brick can be prolonged to about 3 times. The impregnation of the SiO2, into the refractory brick has extremely great economic effects by its application to the burner brick for the hot-blast stove in which the impregnation is not conventionally carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a hot-air stove ceramic burner brick, and more particularly to a modification of a brick portion of a ceramic burner brick by impregnating a brick matrix portion in order to improve acid resistance (SO ₃ gas reactivity resistance).

[0002]

2. Description of the Related Art As a hot-air stove ceramic burner brick, clay brick having excellent heat resistance and spalling resistance, for example, high alumina brick having an Al ₂ O ₃ content of 40-60% by weight, and further Al ₂ O. ₃ High-temperature fired high-alumina bricks having a content of 80% by weight or more are used.

[0003]

In order to improve heat resistance and spalling resistance, it has been remarkably improved to improve the alumina quality of bricks. However, as a result of using it in the actual furnace, the phenomenon that the brick gradually powdered and was worn and damaged occurred. Study this phenomenon in detail, the result of the investigation, to react with Al ₂ O ₃ is SO ₃ Garenga component high alumina bricks, such as described above contained in the gas supplied to the hot air furnace, A
l ₂ (SO ₄ ) ₃ is generated, and SO ₃ easily invades the pores to generate Al ₂ (SO ₄ ) _{3 and the} like, whereby the structure of the brick is destroyed and the structure becomes brittle. It turned out to occur.

[0004] Such the applicant as a problem solving means is impregnated with an aqueous solution of sodium silicate refractory bricks previously, dried, and characterized by forming a SiO ₂ film on the refractory bricks matrix unit, SiO ₂ impregnated hot air Proposed a furnace ceramic burner brick (Japanese Patent Application No. 1-313532)
issue). As a result of further investigation, it was found that the same action and effect can be achieved by using other silicates.

[0005]

The inventors of the present invention succeeded in developing the present invention as a result of various studies and experiments on the modification of the conventional hot-blast stove ceramic burner brick as described above. As described in the above claims, a refractory brick is impregnated with a SiO ₂ -containing solution consisting of one or more of a silicic acid colloidal solution, a silicate ester solution, a potassium silicate solution, and a lithium silicate solution, and dried. refractory brick matrix portion to form a less reactive SiO ₂ film with SO ₃ in the matrix portion from forming a SiO ₂ coating, also reduces the permeability of the brick through the formation of the coating, SO into the brick _It suppresses the penetration of the _three components, suppresses the reaction between the SO ₃ and Al ₂ O ₃ components, and prevents embrittlement and damage.

The SiO ₂ component source is a colloidal solution in which ultrafine particles of SiO ₂ (1 to 100 μm) are dispersed in water. The solid content of SiO ₂ is 20 to 40% by weight, and the Na ₂ content is 0.6% by weight or less. Commercially available under the trade name "Silicadol" containing O, or a silicate solution containing Si.
Orthoethyl silicate containing about 29 wt% of O ₂ solid content, orthomethyl silicate containing about 40 wt% of SiO ₂ solid content, and 4 wt% of SiO ₂ solid content.
0 wt% content to ortho methyl silicate or the like, also, lithium silicate the SiO ₂ solid content is contained LiO ₂ of 1 to 3 wt% at about 20 wt%, SiO ₂ solids 18 to 21 weight %, And one or more potassium silicate solutions containing about 8% by weight of K ₂ O are used.
As a method for impregnating these SiO ₂ -containing solutions, a dip dipping method or a reduced pressure dipping method may be used. The impregnated ceramic burner brick is dried at a temperature of 50 ° C to 300 ° C.

[0007]

Examples Of the various SiO ₂ containing solutions described above, SiO
Silica dol-3 containing 30% by weight of ₂ solid components
0, SiO ₂ solids to 29 ortho ethyl silicate containing wt%, respectively water silicate Lithium solution containing SiO ₂ solid content of 20 wt% 1: those diluted to 1, also silica Doll -30 and SiO ₂ solid content 20
Using a 1: 1 mixed solution containing 1% by weight of potassium silicate diluted with water to 1: 1, a burned product of a high-alumina hot-air stove ceramic burner brick is dipped in the above-mentioned silicate solution for 30 minutes. Impregnation treatment was performed. After the impregnated brick was dried at 110 ° C. for 32 hours, the weight increase (impregnation amount) of the brick was 1.0 to 2.3% by weight.

As a result of a test of the hot-air stove ceramic burner brick subjected to the impregnation treatment, the impregnated brick has extremely excellent acid resistance as compared with the unimpregnated brick. Further, among these, a brick impregnated with silicadol-30 was set in a hot-air stove ceramic burner part of a certain company and tested in an actual furnace.
It was confirmed that the embrittlement damage due to the reaction with O ₃ was reduced to 1/3 or less as compared with the conventional product, and the extension of the usable life was almost tripled.

Table 1 shows various properties before and after impregnation with SiO ₂ .

[0010]

[Table 1]

[0011]

【The invention's effect】

(1) The impregnation of SiO ₂ suppresses the reaction of the hot-air stove ceramic burner brick with SO ₃ gas to prevent embrittlement and damage, and the working life of the brick can be extended about three times. (2) The impregnation of refractory bricks with SiO ₂ is known for other purposes, but the economical effect is extremely large due to the application to hot-blast stove ceramic burner bricks, which has not been performed conventionally. (3) The impregnation treatment can be carried out by an ordinary and simple method.

Claims (1)

[Claims] 1. A refractory brick containing a silicic acid colloidal solution, a silicate ester solution, a potassium silicate solution, and a lithium silicate solution.
A SiO ₂ -impregnated hot-air stove ceramic burner brick, characterized in that a refractory brick is impregnated with a SiO ₂ -containing solution of two or more kinds and dried to form a SiO ₂ coating on the matrix portion of the refractory brick.