Thermal Insulation from Construction Coating Mixed with Porous Calcium-containing Solid Waste

Abstract

To resolve the health risk from the exposure of calcium hydroxide, the target of the present work is to stabilize the solid waste and reuse it as green material for construction buildings. An efficient chemical-wet method is adopted to synthesize CaSO 4 and CaSO 4 ·2H 2 O powders from Ca(OH) 2 waste in the presence of diluted sulfuric acid at ambient temperature. The improved thermal insulation from the construction coating mixed with porous CaSO 4 powders has been investigated. The as-prepared CaSO 4 powders are stable in atmospheric pressure and easily stored as solid waste without toxicity. The construction coating mixed with porous CaSO 4 powders offers excellent thermal insulation capability, as compared with pristine one. The enhanced performance can be attributed to the fact that the CaSO 4 powders possess a vast porous framework, allowing a large amount of air trapped in the construction coating against the thermal transfer. Since the CaSO 4 powders is efficiently prepared from toxic solid waste, the chemical-wet method exhibits a potential route to produce green construction materials for various applications due to its simplicity, high recycling ratio, non-toxicity, low cost, and environmental friendliness.