Calcium hexaluminate lightweight refractory brick and preparation method thereof

The invention relates to a calcium hexaluminate lightweight refractory brick, in particular to a high-quality refractory material with low heat conduction coefficient, good stability under high-temperature reducing atmosphere, good alkali resistance and slag erosion resistance and long service life for a high-temperature kiln lining, and belongs to the technical field of refractory materials. Calcium hexaluminate is used as a main crystal phase, and the sum of the main chemical components Al2O3 and CaO of the calcium hexaluminate is more than 90 weight percent. Calcium carbonate, calcium hydroxide, calcium oxide, limestone or lime or the like is used as a calcium source; and aluminum oxide, aluminum hydroxide or the like is used as an aluminum source. The calcium hexaluminate lightweight refractory brick is prepared by a series processes of mixing the materials uniformly according to the theory of the calcium hexaluminate, grinding the mixture, adding a certain amount of pore forming agent into the mixture and stirring the mixture uniformly, then performing half dry vibration casting, wet adjusting controllable drying, high-temperature air introducing pore formation, one-step reductive reaction sintering, cutting and processing and the like. The lightweight refractory brick for the high-temperature kiln lining has low heat conduction coefficient and long service life, and can provide efficient and energy-saving guarantee for industrial furnace equipment.