Novel Foam Insulation Material Produced by Calcined Phosphogypsum and H2O2

Abstract

A novel foam insulation material was prepared using calcined phosphogypsum (CPG) as the raw material and hydrogen peroxide (H2O2) as a foaming agent. Stable foaming of H2O2 in a CPG-based suspension was achieved. The effects of H2O2 on the mechanical properties, thermal conductivity, and pore structure of the CPG-based foam insulation materials were investigated. The results showed that, with increasing H2O2 content, the expansion volume increased but the growth rate decreased. The total porosity and macroscale porosity (>100 μm) first increased and then plateaued, while the microscale porosity (<100 μm) first increased and then decreased before plateauing. When the content of H2O2 was 4%–5%, CPG-based foam insulation materials with low bulk density (≤500 kg/m3), low thermal conductivity [≤0.13 W/(m·K)], and acceptable compressive strength (≥0.24 MPa) were manufactured; these values are similar to those of other thermal insulation materials, such as cement foam and geopolymer foam in low density ranges.