The invention discloses an 
alumina bubble lightweight insulating 
refractory casting material, which comprises the following components in percentage by weight: 10 to 50 percent of 
alumina bubbles, 5 to 15 percent of 
mullite with the grain 
diameter of 5 to 3 millimeters, 5 to 20 percent of 
mullite with the grain 
diameter of 1 to 3 millimeters, 10 to 20 percent of 
mullite with the grain 
diameter of 0 to 1 
millimeter, 1 to 13 percent of swelling agent, 10 to 25 percent of 
fine powder, 10 to 20 percent of micro 
powder, 0.1 to 1 percent of water 
reducing agent and 5 to 20 percent of composite 
aluminate cement. The 
casting material has the characteristics of carrier weight reduction, high 
temperature resistance, good heat insulation effect, large strength, convenient and practical operation, and suitability for being used at the temperature of between 1,000 and 2,000, can be used for integrally 
casting, spraying, 
coating and repairing, and not only meet the requirement of 
smelting special steel, but also meet the requirements of 
refractory materials for hot-blast stoves, furnace tops, furnace walls, 
petrochemical cracking furnaces, systems for 
chlorine and 
sulfur removal, 
slag discharge and catalytic 
cracking, electric 
fluidized bed boilers, flues and the like.