Preparation and characteristics of magnesium phosphate cement based porous materials

Magnesium phosphate cement based porous materials (MPCPM) were prepared by means of a chemical foaming process using zinc powders as foaming agent. The influence of the zinc content, W/S ratio and particle size of ammonium dihydrogen phosphate (ADP) on the viscosity, temperature evolution, compressive strength, flexural strength and thermal conductivity of the MPCPM was investigated. The results indicate that with higher content of zinc powder and W/S ratio, a longer hardening time of slurry, higher viscosity values, lower hydration temperature, less mechanical strength and lower thermal conductivity of the MPCPM can be obtained. The effects of the particle size of ADP on the properties of MPCPM are analogous to those of the content of zinc powder and W/S. Strong linear relationships can be found between the dry density or porosity and the compressive strength or thermal conductivity of prepared porous materials. The results also show that the MPCPM has good potential to be used for fireproofing doors and high temperature furnace insulation lining due to its light weight, high strength, and thermal and acoustic insulation.