Sialon bonded magnesium aluminum spinel refractory material for cement rotary kiln and preparation method

Abstract

The invention relates to a sialon-bonded magnesium aluminate spinel refractory material for a rotary cement kiln and a preparation method and belongs to the field of refractory materials. The chemical formula of utilized sialon is Si(6-Z)AlZOZN(8-Z), wherein Z is equal to 1. The sialon-bonded magnesium aluminate spinel refractory material comprises the following raw materials: high-purity magnesia, alumina micropowder, silicon nitride and metal aluminum powder, and phenolic resin serves as a bonding agent. The preparation method comprises the steps of weighing the raw materials according to the proportion during production, mixing to obtain pug, carrying out compression molding, drying at 80-200 DEG C for 24-36 hours, and carrying out nitriding and sintering at 1200-1500 DEG C. According to the preparation method, by utilizing a sialon-bonded phase generated by a reaction based on the in situ synthesis of magnesium aluminate spinel, the refractory material has the following excellent physical property indexes: the apparent porosity is 12%-18%, the volume density is 2.80g / cm<3>-3.20g / cm<3>, the normal temperature compression strength is 110MPa-240MPa, and the refractoriness under load (0.2MPa*0.6%) is more than or equal to 1680 DEG C; meanwhile, the refractory material has good thermal shock resistance, excellent wear resistance, erosion resistance and structural flexibility, great market potential and good social benefit and is applicable to a transitional zone of the rotary cement kiln at a severe environment.

Description

technical field [0001] The invention relates to preparing a refractory material for a cement rotary kiln transition zone, in particular to a sialon (Z=1) combined magnesium aluminum spinel refractory material and a preparation method for a cement rotary kiln transition zone. Background technique [0002] With the improvement of cement kiln production process and mechanical properties, and the increasing output, the requirements for refractory materials are becoming more and more stringent. At present, due to the increase of kiln temperature and the acceleration of kiln speed, the unit output of new dry process cement rotary kiln is increased; the kiln diameter is enlarged; the components such as alkali, sulfur and chlorine are severely eroded, and the components such as alkali sulfate and chloride are volatilized and condensed repeatedly. ; A series of reasons such as complex kiln system and low operation rate make the refractory materials used in the transition zone of ceme...

AI Technical Summary

Problems solved by technology

However, periclase-magnesia-aluminum spinel bricks also have insurmountable shortcomings: (1) The thermal conductivity is large, which easily leads to excessively high kiln temperature, which reduces the rigidity of the kiln shell, causes elliptical deformation, and aggravates the mechanical stress of the material

(2) Poor corrosion resistance, the spinel component of the magnesia spinel brick reacts with CS or CA in the cement clinker under superheated conditions to form C with a low melting point 12 A 7 , the viscosity of the melt is also low, resulting in burning of the kiln skin, causing corrosion of spinel minerals, and short service life. The above shortcomings limit its use in high temperature zones

At present, silicon carbide products combined with Sialon are being used in various furnace linings and high-temperature components, especially for the lining between the bosh and the lower part of the furnace shaft of the blast furnace, showing greater advantages. Sialon Combined corundum materials have also been used in blast furnace ceramic cups and ladle permeable bricks, but Sialon combined magnesia-aluminum spinel refractory materials have not been reported yet