JPH0822779B2 - Cushioning silica mortar - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning silica mortar used for partial repair of various kilns.

[0002]

2. Description of the Related Art Among various kilns for iron making, a coke oven has a very long operating period, and it is said that the life of the oven is 30 or 35 years. However, when the furnace wall such as the carbonization chamber is partially damaged and expanded, the furnace wall bricks are partially reloaded and repaired during the warm period. In this case, the expansion of the brick, which is rapidly heated during reuse, must be absorbed by the mortar. However, until now there was no mortar that has contractibility, so the following method was used.

Use a mortar made by adding sawdust wood scrap to a commercially available silica mortar; use a commercially available silica mortar to increase the joint thickness; install an expansion absorber such as ceramic fiber at one or two places. Use intensively;

[0004]

However, when wood chips are added to the silica mortar, the workability of the mortar is deteriorated and the carbonization disappearance temperature of the wood chips is high at the time of heating, so that the low temperature range (100 It is difficult to obtain the expansion and absorption of the silica brick at (-300 ° C.), and the mortar itself becomes porous, resulting in a decrease in airtightness and strength.

Commercial silica mortar expands when heated,
During partial repair (so-called frame repair), the expansion and absorption of the repaired silica brick was insufficient, leading to the destruction of the brick. The cause of the brick destruction is the thermal expansion of silica stone brick is 100 ~ 30
This is because the temperature rapidly increases in the temperature range of 0 ° C. The expansion due to the expansion of the silica bricks in this low temperature range could not be absorbed by the commercially available silica mortar, and the bricks were crushed.

Further, when the ceramic fibers are used for expansion and absorption, after the heating is completed, the joints between the ceramic fibers and the bricks may cause joint breakage, which may cause a problem in the airtightness of the furnace wall structure.

As described above, it has been difficult until now to carry out warm repair of silica coke oven bricks without problems.

[0008] Therefore, an object of the present invention is to provide a cushioning silica mortar having a compressibility which is used for partial repair of various kilns.

[0009]

Cushioning silica mortar of the invention According to an aspect of the silica brick powder 50-9 5 wt%, foamed synthetic resin 0.5 to 15 wt%, the inorganic fibers from 0.5 to 40% by weight, and an organic Raw material mixture 10 consisting of 0.1 to 4% by weight of paste
It is characterized in that 50 to 400 parts by weight of water is externally added to and mixed with 0 part by weight.

[0010]

The present invention is to prepare a cushioning silica mortar having a contractibility capable of absorbing the thermal expansion of silica brick in each temperature range. Therefore, 1 for silica mortar
A foamed synthetic resin that shrinks at a temperature of 00 to 300 ° C. is added.

However, there are problems such as a difference in specific gravity between the silica brick powder and the foamed synthetic resin, and the fact that the foamed synthetic resin is not compatible with water. Therefore, by adding inorganic fibers and organic glue as a so-called tie material, the specific gravity is increased. The target cushioning silica mortar was obtained by suppressing the separation due to the difference and adjusting the proper water retention time.

It is effective to add a plastic material such as clay or clay as a binder, but Al ₂ O ₃ in the clay reacts with SiO ₂ in the silica mortar to give an adverse effect in a high temperature range. The cushioning silica mortar of the present invention having good workability was obtained without adding clay or the like by devising the mixing ratio.

The cushioning silica mortar of the present invention comprises 50 to 95% by weight of silica brick powder and 0.5 to 1 of foam synthetic resin.
5% by weight, inorganic fiber 0.5-40% by weight, organic glue 0.1-
It is obtained by adding water to a raw material mixture consisting of 4% by weight and kneading the mixture by a conventional method.

The silica stone powder used in the cushioning silica mortar of the present invention is a crushed product of unused silica stone such as a corner cutout product generated during the production of silica brick, or an impure material used in a coke oven and a hot blast furnace for a blast furnace. It is a crushed product of used silica stone brick with no components. If the amount added is less than 50% by weight, the strength of mortar cannot be obtained. If it exceeds 95% by weight, the shrinkability cannot be obtained. The particle size of the silica stone powder to be used may be 0.5 mm or less, but if the particle size is coarse, the particles become clogged and difficult to shrink, so 0.3 mm or less is preferable.

The foamed synthetic resin added to the cushioning silica mortar of the present invention is styrofoam, which has a smooth surface in the form of beads or is crushed and has a particle size of 1 to 3 m.
m is preferable. If the amount of the expanded synthetic resin added is less than 0.5% by weight, the shrinkability is insufficient. In addition, 15% by weight
If it exceeds the range, strength is reduced and airtightness is deteriorated.

The inorganic fibers used in the cushioning silica mortar of the present invention are silicic fibers commercially available under the trade name of Cera Bora (Union Kasei Co., Ltd.) or have a fiber diameter of 10 μm.
In the following, glass fibers, ceramic fibers and rock wool fibers having a length of 10 mm or less can be used. If the addition amount is less than 0.5% by weight, the effect of the silica stone powder and the foam synthetic resin as a binder is not exerted, and the silica stone powder and the foam synthetic resin are separated in a short time after kneading, and the work cannot be performed. On the other hand, if it exceeds 40% by weight, the hot strength in the high temperature range is lowered, and softening deformation occurs, which makes it impossible to maintain the brick stack structure.

The organic paste added to the cushioning silica mortar of the present invention is used for the purpose of obtaining workability during mortar construction. CMC, water-soluble cellulose ether,
Methyl cellulose, polyvinyl alcohol or dextrin, natural gum derivative and the like can be used. When the amount of the organic paste added is less than 0.1% by weight, the water retention time becomes short and the workability deteriorates. On the other hand, if it exceeds 4% by weight, the water retention time becomes too long, and when the work is carried out, settling occurs and the work takes a long time.

Powder mixture 10 obtained by the above-mentioned conventional method
Appropriate amount of water for 0 parts by weight (50-400 parts by weight on the outside)
In addition, the cushioning silica mortar of the present invention obtained by kneading by a conventional means has good dispersibility with silica brick powder, foam synthetic resin, and inorganic fiber, and has good water-holding time and good workability. It is a good mortar and has a high stress absorbing property against the thermal expansion stress of the brick after furnace construction.

Although the cushioning silica mortar of the present invention has been described based on the warm repair of the coke oven, it goes without saying that it can be used for other ovens.

[0020]

EXAMPLES Examples Table 1 below shows the composition, quality characteristics and practical test results of the cushioning silica mortar of the present invention product and the mortar of the comparative product.

[0021]

[Table 1]

In Table 1, the shrinkage rate is the expansion rate (+) and the shrinkage rate when the thermal expansion rate is measured under a load of 0.2 MPa.
(-); The adhesive strength is the peel strength measured by a three-point bending test after bonding two bricks with mortar and treating at the above temperature and time; the practical test is combustion of a heavy oil burner heating furnace. After using 3 kinds of mortar on the wall of 1 × 1m in the kiln and using a commercially available silica brick with a joint thickness of 4 mm, it was dried at 110 ° C. for 48 hours and then heated at 1300 ° C. for 50 hours. Indicates the situation, and ○ indicates good,
The mark Δ indicates that the joint is broken, and the part of X brick is crushed.

Example 2 The product No. 2 of the present invention was used for warm repair of the carbonization chamber wall of the coke oven, and silica stone bricks were deposited. There was no crushing of bricks or push-up of the structure at the temperature rise after repair, and it was in use for 3 years and 5 months after that, but it is still in use.

[0024]

The cushioning silica mortar of the present invention is
Since it has shrinkability in the thermal expansion temperature range of silica brick, it is possible to suitably perform warm repair of a coke oven or the like.

Claims (1)

[Claims] 1. A silica brick powder 50-9 5 wt%, foamed synthetic resin 0.5 to 15 wt%, an inorganic fiber, 0.5 to 40 wt% and organic adhesive 0.1-4 wt% raw material mixture 10
Cushioning silica mortar characterized by adding 50 to 400 parts by weight of water to 0 part by weight and adding it.