A process is disclosed for producing cement clinker, comprising the steps of:
a)
providing a mixture of ground calcareous materials and ground argillaceous materials;
b) heating the mixture of step a) to a temperature sufficient to calcine and fuse
the ground materials to form the cement clinker, and thereby producing an exhaust
gas containing CO2; c) catalysing the hydration of at least a portion
of the CO2 contained in the exhaust gas and producing a solution containing bicarbonate
ions and hydrogen ions; and d) adding to the solution obtained in step c) metal
ions, and adjusting the pH of the solution to precipitate a carbonate or said metal.
Preferably, the metal ions are Ca++ obtained from the dissolution of
a material selected from the group consisting of CaCl2, cement kiln
dust and sea salts and the carbonate is CaCO3 which is advantageously
recycled into the process by adding the CaCO3 to the mixture of step
a). A cement plant for performing this process is also disclosed.
