Characteristics of Sorel cement prepared from impure materials

Production of potassium nitrate from potassium chloride and magnesium nitrate is related with the production of by-product, which is water solution of MgCl₂ having concentration (24-30) mass %. Along with magnesium chloride this solution contains also nitrates and potassium and calcium cations. This solution can be used as defrosting agent or as a component for the production of building material based on Sorel cement. Sorel cement is material originating from the reaction of MgCl₂ solution with solid MgO of suitable reactivity which depends on the temperature of calcinations of MgCO₃ and size of MgO particles. Sorel cement paste is prepared by mixing MgO and MgCl₂ in molar ratio 9 : 1 with the addition of water in appropriate amount. This cement settles in 2 hours and it can be treated within 24 hours, depending on the reactivity of MgO. This paper deals with the preparation and properties| of Sorel cement made of by-product (MgCl₂) from the production of fertilizer KNO₃ and MgO prepared from Slovak magnesite (Jelsava) with high content of impurities. We will show that properties of this material are suitable for application in building industry.