CN103204685A - Abrasion-resistant and fire-resistant repairing material for membrane type water walls - Google Patents

Abstract

The invention discloses an abrasion-resistant and fire-resistant repairing material for membrane type water walls. The repairing material comprises aggregates, powder, gelling materials and bonding agents which are mixed together. The weight percentage of the gelling materials is 1-5%, the weight percentage of the bonding agents is 12-15.5% times the total weight of the aggregates, the powder and the gelling materials, the aggregates comprise, by weight, 50-70% of brown fused alumina particles or white fused alumina particles, sizes of the brown fused alumina particles or white fused alumina particles are larger than 74 micrometers and are smaller than or equal to 1 millimeter, the powder comprises, by weight, 10-30% of brown fused alumina powder or white fused alumina powder, 1-5% of chromium oxide micro-powder and 14-20% of alpha-Al<2>O<3> micro-powder, and the size of the brown fused alumina powder or white fused alumina powder is smaller than or equal to 74 micrometers. The abrasion-resistant and fire-resistant repairing material has the advantages that the repairing material is used for quickly repairing damaged coatings on surfaces of the membrane type water walls in circulating fluidized bed boilers, and is high in strength and excellent in cohesiveness and abrasion resistance, the coatings are not easy to damage or crack again, accordingly, the repairing frequency of fire-resistant materials of the water walls is reduced, energy is saved, the efficiency is improved, and the running cost of the boilers is lowered.

Description

Abrasion-resistant and refractory repair material for membrane water wall

technical field

The invention relates to a refractory material, in particular to a wear-resistant and refractory repairing material used on a film-type water wall of a circulating fluidized bed boiler in a thermal power plant.

Background technique

Circulating fluidized bed boiler technology is a high-efficiency, low-pollution and clean combustion technology developed in the past ten years. The slag can be comprehensively utilized and other advantages. However, the construction system of the circulating fluidized bed is complex, the construction volume is large, and the flow rate of coal powder and flue gas in the combustion chamber is high. The water wall material forms scours and impacts at various angles, so it requires high performance of refractory materials, especially wear resistance. However, the refractory materials currently used in circulating fluidized bed boilers use high-alumina clinker or fused corundum as raw materials, which have high cement content, insufficient wear resistance, low compressive and flexural strength, short service life, and are prone to local damage , so it needs to be repaired or replaced frequently, which affects the normal operation of the boiler and consumes a lot of manpower and materials.

Contents of the invention

The purpose of the present invention is to provide a wear-resistant and refractory repairing material for the above problems, which can quickly repair the damaged coating on the surface of the membrane water wall in the circulating fluidized bed boiler, and reduce the surface of the membrane water wall. Coating repair frequency, thereby reducing boiler operating costs.

In order to achieve the above object, the technical solution adopted in the present invention is: a wear-resistant and refractory repairing material for membrane water cooling wall, the repairing material is composed of aggregate, powder, and cementitious material with a weight percentage of 1 to 5%, and a binder accounting for 12-15.5% of the total weight of the first three, the aggregate includes brown corundum particles or white corundum particles with a weight percentage of 50-70%, and the particle size of the brown corundum particles or white corundum particles Greater than 74μm, less than or equal to 1mm, the powder includes 10-30% by weight of brown corundum powder or white corundum powder, 1-5% of chromium oxide micropowder, and 14-20% of α-Al2O3 micropowder. The particle size of the brown corundum powder or white corundum powder is ≤74μm.

Further, the binding agent is one of aluminum sol, silica sol, phosphoric acid, aluminum dihydrogen phosphate or aluminum sulfate or a combination thereof in any proportion.

Further, the cementitious material is one of magnesia, Portland cement or slaked lime or a combination thereof in any proportion. The cementitious material is used to improve the high temperature performance and construction performance of the repair material.

Preferably, the particle size of the α-Al2O3 micropowder is 5 μm.

The preparation method of the repairing material of the present invention is simple, and only needs to measure and mix the aggregate, powder, and the components of the cementitious material used as additives, and mix them uniformly; the on-site construction before use is based on the mixed solid quality Add an appropriate amount of binder and stir evenly, and the resulting mixture is the repair material. When in use, apply the uniformly mixed repair material on the surface of the membrane water wall in the circulating fluidized bed boiler or the part to be repaired, without vibration and pounding, and the fire can be ignited 24 to 50 hours after the construction is completed. The repair material can be used for repairing the surface of the membrane water cooling wall or the damaged part of the refractory lining.

Compared with prior art, the present invention has following advantage:

First, the main component of brown corundum and white corundum is Al2O3, which can react with chromium oxide to form aluminum chromium spinel under high temperature conditions, which not only improves the strength and wear resistance of the repair material, but also makes the thermal shock of the repair material Stability has been improved.

Second, the addition of an appropriate amount of binder and cementitious material makes the repair material have good adhesion and wear resistance, and the coating is not easy to damage or crack, thereby reducing the repair frequency of water-cooled wall refractory materials, saving energy, and improving Improve efficiency and reduce boiler operating costs.

Its three, the compressive strength and flexural strength of this repair material are obviously better than traditional white corundum wear-resistant castables and high-alumina wear-resistant castables; The combination is tighter, which increases the bulk density of the repair material, and further enhances the wear resistance of the repair material.

Detailed ways

The present invention will be further described below in conjunction with the examples, but the present invention is not limited to the following examples. Unless otherwise specified, the percentages used in the present invention are all percentages by weight, wherein the following percentages refer to the percentages of the weight of each component in the total weight of the aggregate, powder, and cementitious material.

Example 1:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Example 2:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Example 3:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Example 4:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Example 5:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Embodiment 6:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

Embodiment 7:

The components and content of the wear-resistant and refractory repair material for membrane water wall are as follows:

This repairing material has good compressive strength and flexural strength. In addition, because the aggregate particle size selected in the present invention is relatively low, the combination between materials is tighter, the bulk density of the repairing material is improved, and the repairing effect is further enhanced. wear resistance of the material. After testing, the volume density, compressive strength, and flexural strength of the repairing material of the present invention and the traditional white corundum wear-resistant castable and high-alumina wear-resistant castable are compared in the following table:

Table 1

Claims (4)

1. abrasion-proof and refractory repair material that is used for membrane wall; it is characterized in that: this repair material is 1～5% gelling material by aggregate, powder, weight percent; and the wedding agent that accounts for former three gross weight 12～15.5% mixes; described aggregate comprises that weight percent is 50～70% brown corundum in granules or white fused alumina particle; the granularity of described brown corundum in granules or white fused alumina particle is greater than 74 μ m; be less than or equal to 1mm; described powder comprises that weight percent is 10～30% brown alundum powder or white alundum powder, 1～5% chromic oxide micro mist, and 14～20% α _-Al ₂O ₃Micro mist, the granularity of described brown alundum powder or white alundum powder≤74 μ m.

2. the abrasion-proof and refractory repair material for membrane wall according to claim 1, it is characterized in that: described wedding agent is the combination of a kind of or its arbitrary proportion in aluminium colloidal sol, silicon sol, phosphoric acid, aluminium dihydrogen phosphate or the Tai-Ace S 150.

3. the abrasion-proof and refractory repair material for membrane wall according to claim 1, it is characterized in that: described gelling material is the combination of a kind of or its arbitrary proportion in magnesia, silicate cement or the slaked lime.

4. the abrasion-proof and refractory repair material for membrane wall according to claim 1 is characterized in that: described α _-Al ₂O ₃The granularity of micro mist is 5 μ m.