Lightweight periclase-magnesium aluminate spinel refractory material for rotary cement kiln and preparation method thereof

Abstract

The invention relates to a lightweight periclase-magnesium aluminate spinel refractory material for a rotary cement kiln and a preparation method thereof. According to the scheme, the preparation method comprises the following steps of: uniformly dispersing 0.2 to 4wt% of magnesite micro powder and 0.2 to 4wt% of active alpha alumina micro powder into 5 to 8wt% of binding agent to obtain a modified binding agent; adding 50 to 70wt% of porous periclase-magnesium aluminate spinel ceramic particles to a vacuum agitating machine; vacuumizing to be below 2.5kPa; maintaining the constant pressure for 3 minutes; adding the modified biding agent to the vacuum agitating machine; agitating for 10 minutes; closing a vacuumizing system; then adding 10 to 25wt% of porous periclase-magnesium aluminate spinel ceramic fine powder, 4 to 20wt% of fine magnesia powder, and 1.5 to 4wt% of magnesium aluminate spinel fine powder to the vacuum agitating machine; uniformly agitating; mechanically pressing and modeling; drying; and maintaining the temperature of 1,500 to 1,650 DEG C for 2 to 10 hours. The lightweight periclase-magnesium aluminate spinel refractory material for the rotary cement kiln has the advantages of being low in heat conductivity, high in intensity, high in thermal shock resistance, high in kiln coating performance, and high in resistance to medium erosion.

Description

technical field [0001] The invention belongs to the technical field of lightweight refractory materials. Specifically relates to a lightweight periclase-magnesia-alumina-spinel refractory material for a cement rotary kiln and a preparation method thereof. Background technique [0002] The refractories used in the firing zone of traditional cement rotary kilns are dense refractory materials. These dense refractory materials will cause two serious problems in cement production: first, it is easy to cause the temperature of the cement kiln cylinder to be too high, and a lot of heat is wasted; second, The heavy weight of the cylinder will increase the stress of the cylinder in the tire belt area and accelerate the deformation of the cylinder. [0003] In order to reduce the heat loss and weight of the cement rotary kiln shell, it has been proposed to reduce the weight of the existing dense refractory materials for the firing zone of cement rotary kilns by producing multi-layer ...

AI Technical Summary

Problems solved by technology

[0002]The traditional cement rotary kiln firing zone refractories are dense refractory materials, these dense refractory materials will cause two serious problems in cement production: first, it is easy to cause The temperature of the cement kiln cylinder is too high, which wastes a lot of heat; second, the cylinder is heavy, which will increase the stress of the cylinder in the belt area and accelerate the deformation of the cylinder

However, there are two insurmountable problems in the existing gradient energy-saving composite bricks: (1) It is difficult to sinter. When the materials at both ends are fired at high temperature, the refractory end and the heat insulation end will cause cracks due to inconsistent shrinkage; (2) The strength is low, although it is dense The strength of the refractory end is high, but the strength of the insulation layer and the interface is low. When subjected to extrusion force, shear force, thermal stress, etc. from time to time, it is easy to break the interface and the insulation layer, resulting in dense refractory material at the outer end. drop

"A kind of aluminum-magnesium refractory brick containing lightweight porous aggregate and its preparation method" (ZL 200710052474.0)) patent technology provides a kind of high apparent porosity, small average pore size, low thermal conductivity and resistance to neutral or Alumina-magnesia refractory bricks containing lightweight porous aggregates with strong alkaline medium erosion ability, but this kind of refractory bricks cannot be used in the firing zone of cement rotary kiln