Magnesium　phosphate　cement　(MPC)　prepared　by　dead-burned　MgO　is　linked　to　significant　carbon　emissions.　The　properties　of　traditional　MPC　prepared　by　dead-burned　MgO　(TMPC)　and　natural　brucite　(NBMPC)　were　compared　in　this　work.　The　dissolution　characteristics　and　reaction　mechanisms　of　brucite　in　ammonium　dihydrogen　phosphate　(ADP)　and　potassium　dihydrogen　phosphate　(KDP)　solutions　were　investigated.　Under　comparable　setting　time,　NBMPC　required　more　borax,　yet　achieved　a　28　d　compressive　strength　of　42.5　MPa.　Wetting　of　brucite　by　ADP　was　facilitated　by　hydrogen　bonding,　with　initial　dissolution　accelerated　by　lower　pH.　Dissolution　in　phosphate　solutions　showed　planar　and　punctate　patterns.　The　higher　activity　of　NH4+　in　the　ADP　solution　enabled　it　to　approach　the　reaction　interface　more　effectively,　leading　to　the　formation　of　MgNH4PO4·6H2O,　MgHPO4·3H2O,　and　calcium　phosphate　compounds.　These　reactions　occurred　on　the　brucite　surface　and　in　solution,　resulting　in　shorter　half-life,　higher　heat　release,　and　faster　early　stage　precipitation　and　conductivity　reduction　in　NBMA-S.　As　the　reaction　progressed,　the　product　coated　the　brucite　surface,　inhibiting　further　dissolution.　The　reaction　mechanisms　in　NBMA-S　and　NBMK-S　shifted　from　crystallization　nucleation　and　crystal　growth　(NG)　to　diffusion　(D)　control,　with　diminishing　differences　in　product　formation　over　time.　©　2025　Elsevier　Ltd