Study On Sintering Characteristics Of Magnesia-Calcia Material

In the present work,calcination and sinterability of mixed Mg?OH?₂-magnesite and Ca?OH?₂-magnesite powders were investigated by using magnesite and CaO?Chemical agent?as staring materials,and characterized by means XRD,TG-DSC,FSEM and FactSage thermodynamic simulation.The results show that:"Decomposition-carbonization-decarbonization" reactions of Mg?OH?₂ in the Mg?OH?₂-MgCO₃ powders and Ca?OH?₂ in the Ca?OH?₂-MgCO₃ powders during calcinations is proved most important to prevent MgO in calcined powder from agglomerating and to improve sinterability of the calcined powders.High homogeneous particle structure in calcined Mg?OH?₂-MgCO₃ and Ca?OH?₂-MgCO₃ powders were achieved and high density of 3.08g/cm³ and 3.34g/cm³ were reached in MgO and MgO-CaO clinkers,including 20% MgO and 30% CaO in starting materials,respectively,after sintering at 1650?×3h in the present work.Grinding treatment of the calcined Mg?OH?₂-MgCO₃ and Ca?OH?₂-MgCO₃ powders improved sinterability of both calcined powders.Bulk density of the MgO and MgO-CaO clinkers,which calcined powders including 20% MgO and 30% CaO in starting materials were ball milled for 30 min.,reached 3.16 g/cm³ and 3.40 g/cm³ respectively after sintering at 1650 ? for 3h.