Production of Heat Insulator from Coal Ash Discharged from a Pressurized Fluidized-Bed Combustor

In this work, the technology of using pressurized fluidized-bed combustor ash to produce a heat insulator by curing with steam at low temperature was studied and developed. It was found that (1) the produced heat insulator mainly consists of calcium silicate hydrates, calcium aluminate sulfate, and hemihydrate gypsum, (2) the produced heat insulator has three kinds of structures, which are the microscopic porous structure, the void, and the network structure, and (3) all the insulators produced in this work have thermal conductivities lower than the commercial material selected for the comparison, and some of the new insulators have also significantly higher compressive strength.