MgCl2 + CaCl2 + 4KHCO3 → CaMg(CO3)2 + 4KCl + 2CO2 + 2H2O
Magnesium chloride react with calcium chloride and potassium hydrocarbonate to produce calcium-magnesium carbonate, potassium chloride, carbon dioxide and water. Potassium hydrocarbonate - concentrated, heated solution.