TW202100465A - Precast block for coke oven and coke oven using same - Google Patents

Abstract

The present invention provides a precast block for a coke oven, which exhibits sufficient fluidity during pouring construction. This precast block for a coke oven is mainly composed of an amorphous silica raw material, and where the content ratio of a siliceous raw material having a particle size of less than 10 [mu]m in 100% by mass of a siliceous raw material containing the amorphous silica raw material is denoted by A (% by mass), and the content ratio of a siliceous raw material having a particle size of less than 1 [mu]m is denoted by B (% by mass), A is 15-19 (% by mass) and B/A * 100 is 45-85.

Description

Clinker block for coke oven and coke oven using it

The present invention relates to a gluten cake suitable for use in a coke oven and a coke oven using the gluten cake.

In the past, coke ovens were lined with silica tiles. However, in the case of using silica for smelting tiles, a large number of smelting tiles must be constructed, so there is a problem that construction time is required. For this reason, in recent years, especially in hot repair construction, most of the constructions have been implemented using siliceous stone blocks, which are easier to grow in size than silica tiles.

However, for coke ovens, if there are defects on the wall of the carbonization chamber (cavities, holes, defects, etc. due to bubbles), the coke will be stuck in this part, which will cause resistance when extruding the coke, which will cause obstacles to the operation. Therefore, the block used on the wall of the carbonization chamber must be a clean surface without unevenness, and must be free of defects such as voids, holes, and damage caused by bubbles.

On the other hand, in order to build a coke oven with good accuracy and efficiency, the size of coke oven blocks (Patent Document 1) and the mechanization and automation of coke oven construction (Patent Document 2) have increased in recent years. Generally, although vibration is applied to degas during the inflow construction in the manufacture of 預鑄鑄, but if the 預鑄 block is large, the degassing during the inflow construction is insufficient, and it is easy to produce voids and air bubbles in the 預鑄block hole. In addition, because the coke oven smelt is a refractory with siliceous raw material as the main raw material, the density of the mortar (paste-like mixture) that is poured into the construction is the same as that of the mortar that usually uses alumina as the main raw material. The comparison is low, the buoyancy of the air contained in the mortar is low, and the pores are not easy to remove. For these reasons, the siliceous mortar used for coke oven mortar must be given a high level of fluidity, and it must be fully degassed during the flow into the construction stage. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2017-133765 A [Patent Document 2] JP 2017-122178 A

[The problem to be solved by the invention]

The problem to be solved by the present invention is to provide a briquettes for coke ovens that exhibit sufficient fluidity during inflow construction. [Means to solve the problem]

In order to solve the problem, the inventors have repeated the results of experiments and found out the particle size composition of the siliceous raw material, the main raw material of the coke oven gluten cake, especially the particle size composition of ultrafine powders with a particle size of less than 10μm and a particle size of less than 1μm. The particle size is balanced, which has a greater impact on the fluidity of the inflow construction.

In other words, according to one aspect of the present invention, there is provided a coke oven sintering block, which uses amorphous silicon oxide raw material as the main raw material, and contains 100% by mass of the amorphous silicon oxide raw material. When the content of siliceous materials with a diameter of less than 10μm is set to A (mass%), and the content of siliceous materials with a particle size of less than 1μm is set to B (mass%), A is 15-19 (mass%) %), B/A×100 is 45~85.

In addition, according to another aspect of the present invention, a coke oven using the calcined crumb for coke oven of the present invention is provided. [Invention Effect]

According to the present invention, the content A of the siliceous raw material whose particle size is less than 10 μm in 100% by mass of the siliceous raw material is set to 15-19 (mass%), and the content A and the particle size The ratio (B/A×100) of the content rate B (mass%) of the silicon oxide raw materials up to 1μm is set to 45~85, which can exert sufficient fluidity during inflow construction. In addition, by this, the filling property during the inflow construction is improved, and by forming a dense structure, the porosity can be reduced.

The briquette for coke oven of the present invention is based on siliceous raw material, in which a refractory raw material compound with amorphous silicium raw material as the main raw material is obtained by adding hardener, dispersant and water, kneading and inflow It is characterized by the particle size composition and even particle size balance of the silica raw material in the refractory raw material complex. That is to say, the feature of the present invention is to set the content of 100% by mass of the siliceous raw material containing amorphous silica raw material with a particle size of less than 10μm as A (mass%) and the particle size less than 1μm When the content rate of the silicon oxide raw material is set to B (mass%), A is 15-19 (mass%), and B/A×100 is 45-85. Moreover, in the present invention, the content rate A of siliceous material with a particle size of less than 10μm and the content rate B of siliceous material with a particle size of less than 1μm are based on the measurement by a laser diffraction particle size distribution measuring device The particle size distribution is specific.

If the content rate A of the siliceous material with a particle size of less than 10μm is less than 15% by mass, or B/A×100 is less than 45, it is impossible to ensure sufficient fluidity for the mortar that flows into the construction. On the other hand, if the content rate A of the siliceous material with a particle size of less than 10μm exceeds 19% by mass, or B/A×100 exceeds 85, the specific surface area of the refractory material complex becomes too large, and it is impossible to obtain a dense structure. With proper construction water volume to ensure sufficient fluidity, as a result, a dense structure cannot be obtained. In addition, B/A×100 is preferably 55 to 75.

Silica raw materials can be roughly divided into amorphous silicon oxide raw materials and crystalline silicon oxide raw materials. In the present invention, amorphous silicon oxide raw materials are used as the main raw materials. Examples of amorphous silica raw materials include fused silica raw materials, fumed silica, silica glass, etc., and examples of crystalline silica raw materials include fired silica and raw silica. The SiO ₂ content of these silicon oxide raw materials is within the range of technical common sense, about 85~99% by mass.

In the present invention, based on the viewpoints of low thermal expansion and densification (lower porosity) of the magnesia, among these silica raw materials, it is preferable to use only amorphous silica raw materials, and more preferably to use only molten oxidation Silicon raw materials and fuming silica. That is, the refractory raw material complex in the present invention is preferably made of fused silica raw material as the main raw material, and the rest is composed of fumed silica only.

The clinker block for coke oven of the present invention is obtained by adding a hardener, a dispersant and water to these refractory raw material mixtures, kneading and pouring, but it is preferable not to add cement as a hardening agent in the present invention. The reason is that if cement is added, it will shrink under the load of high temperature due to the hydration reaction of the cement. As a hardener other than cement, fine powder of alkaline earth metal compounds such as magnesium oxide, magnesium carbonate, magnesium sulfate, slaked lime, calcium carbonate, etc. (specifically, fine powder with a particle size of 75 μm or less) is used. Alkaline earth metal compound fine powder is combined with ultrafine silica powder in the refractory raw material complex (specifically, silica raw material with a particle size of less than 10 μm or a particle size of less than 1 μm) to form a cohesive bond. The addition amount of the hardener is added to 100% by mass of the refractory raw material compound. From the viewpoint of imparting strength performance effects, it is preferably 0.05% by mass or more, and from the viewpoint of maintaining high thermal strength, it is preferably 1.9 Less than mass%. Moreover, the so-called "cement" in the present invention is tricalcium silicate (3CaO‧SiO ₂ ), dicalcium silicate (2CaO‧SiO ₂ ), tricalcium aluminate (3CaO‧Al ₂ O ₃ ) and aluminate ferrite calcium _{(4CaO‧Al 2 O 3 ‧Fe 2 O} 3) of mineral-based Portland cement, and calcium aluminate (CaO‧Al ₂ O ₃₎ of mineral-based alumina cement.

Here, when cement is not used as a hardening agent, in order to obtain the strength of the lump through the cohesive combination, it must be a dense structure. In order to achieve the densification of the magma mass, it is necessary to ensure the fluidity with less construction water. As mentioned above, the present invention can ensure sufficient fluidity due to the limited particle size composition of the main raw material siliceous material and even the particle size balance. Obtain a dense tissue with an apparent porosity of 12.5% or less. In addition, the amount of water used for construction in the present invention is added to 100% by mass of the refractory raw material complex, and is preferably from 5 mass% to 6 mass%.

Conventional dispersants such as sodium polyacrylate and condensed phosphates can be added as dispersants. In addition, sintering aids such as phosphates, and conventional additives such as organic fibers can be added.

Thus, the gluten block of the present invention can be used in a coke oven, and is particularly suitable for use on the wall surface of the carbonization chamber. [Example]

Table 1 shows the raw material composition of the examples of the present invention. And Table 2 shows the raw material composition of the comparative example. As refractory raw materials, fused silica raw materials and fuming silica are used. Specifically, as the raw material of fused silica, coarse particles with a particle size of less than 5mm, fine powder with a particle size of less than 0.045mm, and ultrafine powder with an average particle size of 5μm are used. As a fuming silica, the average particle size is 0.2~ About 0.3μm. Moreover, by adjusting the blending ratio of the fused silica raw materials and fuming silica, the content rate A of siliceous raw materials with a particle size of less than 10μm and the content rate of siliceous raw materials with a particle size of less than 1μm are adjusted. B, and then adjust B/A. In addition, fine powder of magnesium oxide with a particle size of 75μm or less as a hardener, condensed phosphate as a dispersant, and phosphate (phosphate glass) as a sintering aid are added separately in addition to 100% by mass of the refractory raw material complex 0.4% by mass, 0.2% by mass, and 1% by mass. The amount of construction water (the amount of water added) is 5.7% by mass in addition to 100% by mass of the refractory raw material complex.

Evaluation About the fluidity and apparent porosity of each case, comprehensive evaluation was performed based on these evaluation results.

The fluidity is evaluated based on JIS2521. The case where the tapping flow value exceeds 162 is recorded as ◎ (excellent), the case of 150 or more and 162 is recorded as ○ (good), and the case of less than 150 is recorded as × (bad).

The apparent porosity is based on the refractory raw material complexes of each example, adding the additives shown in Table 1 and Table 2, then adding water and kneading to produce a hardened body with a shape of 40×40×160mm, and curing it at 40℃×15h , The sample obtained by the drying process at 400°C×8h is evaluated based on JIS2205. In addition, the case where the apparent porosity was 11% or less was recorded as ◎ (excellent), the case exceeding 11% and 12.5% or less was recorded as ○ (good), and the case exceeding 12.5% was recorded as × (bad).

Comprehensive evaluation, when the evaluation of fluidity and apparent porosity are both ◎ (excellent), it is recorded as ◎ (excellent), and when one of them is ◎ (excellent) or both are ○ (good), it is recorded as ○ (good) ), if any one is × (bad), it is recorded as × (bad).

Examples 1 to 8 shown in Table 1 are all examples falling within the scope of the present invention. The fluidity evaluation is ◎ (excellent) or ○ (good) as good, and the comprehensive evaluation is also ◎ (excellent) or ○ (good). ) Is good.

On the other hand, Comparative Examples 1 and 2 shown in Table 2 are examples of lower A, Comparative Examples 3 to 5 are examples of higher A, and Comparative Examples 6 to 8 are examples of lower B/A×100. Example 9 is a case where B/A×100 is higher, comparative example 10 is a case where both A and B/A×100 are lower, and comparative example 11 is a case where both A and B/A×100 are lower. All fluidity evaluations are × (bad), and apparent porosity evaluations are also × (bad).

Claims (4)

A kind of coke oven block, which is based on amorphous silicon oxide raw material as the main raw material, and 100% by mass of the siliceous raw material containing the amorphous silicon oxide raw material has a particle size of less than 10 μm. When the content rate is set to A (mass%) and the content rate of siliceous raw materials with a particle size of less than 1μm is set to B (mass%), A is 15-19 (mass%), and B/A×100 is 45 ~85. For example, the gluten block for coke oven of claim 1, in which the apparent porosity is less than 12.5%. Such as claim 1 or 2 of the coke oven powder, which does not add cement as a hardener. A coke oven, which uses the sintering block for a coke oven as in any one of claims 1 to 3.