On the Preparation of Potassium Carbonate and Magnesium Carbonate from Bittern.(Part 1)

Abstract

Magnesium carbonate reacts with potasium chloride in the presence of CO₂:
2KCl+3MgCO₃·3H₂O+CO₂=2 (KHCO₃·MgCO₃·4H₂0)+MgCl₂This hydrated double salt of KHCO₃ and MgCO₃ is insoluble and can be washed free from MgCl₂with water. If this double salt is decomposed with hot water, the products are K₂CO₃ solution and a precipitate of magnesium carbonate.
2KHCO₃·MgCO₃·4H₂0=K₂CO₃+2MgCO₃+9H₂O+CO₂If decomposed at temperature below 20°C with a suspension of magnesium hydroxide or oxide, the magnesium is precipitated as the trihydrate, and can be re-used.
2KHCO₃·MgCO₃·4H₂O+Mg(OH)₂=K₂CO₃+3MgCO₃·3H₂O+H₂O The authors utilized these reactions to prepare K₂CO₃ and MgCO₃ from bittern. In this report, the fundamental conditions of these reactions were investigated.