Research on the preparation and pore structure of porous brucite-based magnesium phosphate cement

Magnesium phosphate cement offers high strength , excellent temperature resistance, alongside superior bonding properties; but its high density, substantial carbon emissions, and instability in foaming processes restrict its applications in thermal insulation and fire protection. This study employed natural brucite and ammonium dihydrogen phosphate as the base materials for magnesium phosphate cement, while magnesium carbonate, sodium bicarbonate , or sodium dodecyl sulfate (SDS) were used as foaming agents to prepare porous brucite-based magnesium phosphate cement (BMPC). The study focused on investigating the physical and mechanical properties, thermal conductivity , and microstructure of the BMPC. The results indicate that, within the same density range, magnesium carbonate-modified BMPC has the least impact on mechanical properties, while the thermal conductivity can be reduced by 46.6 % and the thermal diffusivity by 110.4 %. The results indicate that, within the same density range, magnesium carbonate-modified BMPC has the least impact on mechanical properties, the proportion of small and medium pores increases, and the fractal dimension is the lowest. BMPC offers advantages such as lightweight, thermal insulation , and low carbon emissions. • A foamed BMPC is innovatively prepared by completely replacing dead-burned MgO with natural brucite. • The pore stability and uniformity of BMPC are evaluated. • MgCO 3 reduces thermal conductivity of BMPC by 46.6 % and thermal diffusivity by 110.4 %. • MgCO 3 can reduce BMPC gas heat transfer, improve heat insulation and fire resistance.