Patent ID: 8715411

Claim:
A process for the manufacture of a clinker for cement, comprising grinding a raw meal comprising Al 2 O 3 , Fe 2 O 3 , and SO 3 in contents such that the formula for calculating SO 3 content is SO 3 =0.261×Al 2 O 3 −0.638×Fe 2 O 3 +k, where 2.5≦k≦3.5, and sintering said raw meal in a kiln where temperature is between 1250° C. and 1350° C. and where the oxygen content in the kiln is between 2.5% and 10% by volume, wherein the Al 2 O 3 content is between 3.0% and 10% by weight and the Fe 2 O 3 content is between 0.5% and 2.0% by weight.