Stress buffering material for prefabricated brick of pellet rotary kiln and manufacturing method of stress buffering material

Abstract

The invention discloses a stress buffering material for a prefabricated brick of a pellet rotary kiln, belonging to the technical field of refractory materials. The stress buffering material comprisesthe following components: 40%-60% of alumina, 10%-20% of a binding agent, 1%-2% of a plasticizer, and 20%-30% of a waterproof emulsion, wherein the alumina comprises alumina particles and fine alumina powder in a weight ratio of 5: 3. The stress buffering material has enough strength and a waterproof function at a normal temperature, can be repeatedly used in the process of heating-cooling-heating, has high-temperature extrusion deformability, is beneficial to pressure release, and can ensure sufficient filling property; and after a temperature is reduced, the material has self-bridging contractibility, so filling of gaps to a full state is always ensured in the temperature rising and falling process, fire penetration is prevented, and stress can be fully released.

Description

Technical field[0001]The invention relates to the technical field of refractory materials, in particular to a stress buffer material for prefabricated bricks in a pelletized rotary kiln and a manufacturing method thereof.Background technique[0002]During the heating process of the high-temperature section of the oxidized pellet rotary kiln, there will be a large number of lumps during the heating process after the kiln is shut down for maintenance. The falling refractory blocks are basically plate-like, and the falling blocks themselves are very strong. Analyzing the dropped refractory block, it was found that the refractory aggregate was cross-faulted, and the sample block was complete and high in strength, which belonged to the whole brick layered peeling. The direct reason is that a large stress is generated at this position, the value of which is greater than the strength of the material itself at this temperature, causing the material to be broken at this position. The phenomeno...

AI Technical Summary

Problems solved by technology

[0004] (1) Expansion joints are reserved, the temperature distribution in the rotary kiln is uneven, and the expansion joints cannot be bridged at the same time. When the oxidized pellets are fired, the pellet powder falls into the expansion joints and will penetrate the kiln body, causing the kiln lining to burn quickly. wear; or increase the degree of pellets united with the kiln ring, affecting the normal operation of the pellet rotary kiln

[0005] (2) The method of adding polypropylene boards can buffer the stress caused by thermal expansion during the heating process, but when the polypropylene boards are burned out, there will also be cases where the expansion joints cannot be bridged at high temperatures, and the pellet powder or liquid The phase will immerse into the interior of the kiln brick along the expansion joint, once the liquid phase touches the steel shell of the kiln body, there will be a risk of burning through the steel shell

However, refractory mud has three negative effects. First, refractory mud is generally water-soluble. When water-soluble fire mud adheres to the surface of kiln bricks, the kiln bricks will absorb the moisture in the fire mud, which will affect the anti-burst of kiln bricks. Performance; second, refractory mud is usually based on low-melting point phase powder, and the low-melting point liquid phase will react with kiln brick materials under high temperature conditions, reducing the refractoriness of kiln bricks and accelerating the damage of kiln bricks; third, refractory mud After the expansion joints run at high temperature for a period of time, it is inevitable that excessive sintering shrinkage will occur, then the expansion joints will become the weak points of the kiln bricks, and the damage of the kiln lining will start from these weak points

[0007] Therefore, it is urgent to find a suitable solution, which can not only solve the hidden dangers brought to the rotary kiln body by the above-mentioned traditional way of reserving expansion joints, but also buffer the expansion stress generated by the pellet rotary kiln during operation.