Study of using Dolomite as Starting Material Resource to Produce Magnesium Oxychloride Cement

摘要

In this paper, the starting materials necessary for producing magnesium oxychloride cement (MOC) were produced from dolomite ore using leaching-carbonation-evaporation-pyrohydrolysis processes. The influences of the molar ratio of MgO/MgCl2 (M-x) and H2O/MgCl2 (H-y) on the properties of the MOC (cured for 7 days) were determined using physico-mechanical methods. SEM and XRD analyses were conducted to determine the change of phase and microstructure of the selected 7-day MOC depending on the production conduction. The experimental results show that the best mix proportion of 7-day MOC was found to be M6.06H14 and its thermal conductivity, flexural strength, and compressive strength values were found to be 1.202 W/mK, 4.22 MPa, and 87.7 MPa, respectively. The water resistance of the MOC was improved by a small amount of H3PO4 (4% of MgO by weight). Consequently, if MOC is produced from dolomite, high-purity synthetic aragonite and CO2 would be obtained as byproducts, which are strongly demanded.