Lightweight corundum-mullite castable and preparation method thereof

Abstract

The invention relates to a lightweight corundum-mullite castable and a preparation method thereof. The the technical scheme is that the preparation method comprises the following raw materials of 40-70wt% of porous corundum-mullite ceramic particles, 10-25wt% of porous corundum-mullite ceramic fine powder, 10-20wt% of corundum fine powder, 1-3wt% of silicon oxide micro powder, 2-4wt% of active alpha aluminum oxide micro powder, 1-5wt% of calcium aluminate cement and 1-5wt% of rho aluminum oxide fine powder; water and a water reducing agent are taken as additives, wherein the weight of the water is 8-20wt% of that of the raw materials, and the weight of the water reducing agent is 0.02-1wt% of that of the raw materials; and the method comprises the steps of: evenly stirring, casting for molding, naturally drying a molded green body for 24h, and finally, drying the product for 8-48h at the temperature of 110 DEG C. The prepared product not only has the performances of high apparent porosity, high strength, low heat conductivity, high medium erosion resistance and the like, but also has the advantages of being convenient to construct, environment-friendly, controllable in apparent porosity and pore size, small in volume change after being burnt, and the like, thus being suitable for a working layer or a permanent layer of a high-temperature kiln or container with the working temperature lower than 1600 DEG C.

Description

technical field [0001] The invention belongs to the technical field of lightweight castables. Specifically relates to a lightweight corundum-mullite castable and a preparation method thereof. Background technique [0002] Corundum-mullite refractories have the advantages of high load softening temperature, low high-temperature creep rate and good thermal shock stability, and are widely used in high-temperature furnaces or containers in ironworks and glass factories. The traditional corundum-mullite refractory material uses dense corundum or mullite as aggregate, which has high thermal conductivity. When it is applied to the working layer of high-temperature kiln or container, it will cause a large amount of thermal conductivity due to the high thermal conductivity of the entire furnace lining heat loss. Since the closer the insulation material is to the heating surface, the better the insulation effect is (Li Nan et al., Refractory Science, Metallurgical Industry Press, 20...

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Problems solved by technology

For example, in the literature on the preparation of mullite-corundum lightweight bricks (Yang Daoyuan et al., Preparation of high-strength and low-thermal conductivity mullite-corundum lightweight bricks, Rare Metal Materials and Engineering, 2009, 38 (2): 1237-1240), Using high-alumina bauxite and silica fume as the main raw materials and polystyrene balls as the pore-forming agent, the lightweight mullite-corundum material was prepared by gel injection molding. The burning of styrene balls causes environmental pollution, and the material has low strength (2.17MPa) and low chemical purity, so it cannot be used in the working layer of high-temperature kilns or containers

Another example is the patented technology of "a corundum-mullite lightweight brick and its preparation method (201110207949.5)", which uses high-alumina bauxite fine powder as the main raw material and polystyrene balls with a particle size of 1-3mm as the pore. The corundum-mullite lightweight refractory material is prepared by using the same agent, but this manufacturing process will also cause environmental pollution, and the refractory material has low chemical purity and large pore size, which is also not suitable for the working layer

Although the patented technology of "a kind of aluminum-silica refractory brick containing lightweight porous aggregate and its preparation method" (200710052470.2) has produced a lightweight corundum-mullite refractory material with high strength and high resistance to medium erosion, it can It is used in the working layer of high-temperature kiln, but its products are stereotyped products, and it cannot prepare refractory materials with complex structures, nor can it be cast on site