Method of producing cement clinker from a source of calcium sulfate

(22) 04.10.2024

(43) 10.04.2025

(57) A method of producing cement clinker from a source of calcium sulfate, comprising - blending a source of calcium sulfate with silica, alumina, and iron oxide containing materials in order to obtain a raw material mixture. the calcium sulfate comprising chemically hound water, - a first step of heating the raw material mixture in the presence of a reducing agent in a first reactor so as to desulfurize the calcium sulfate to obtain a) a pre-calcined material comprising calcium oxide, b) steam, and c) sulfur dioxide, and subsequently - a second step of calcining the pre-calcined material in a second rector to obtain cement clinker.

(71) Holcim Technology Ltd (CH), 6300 Zug (CH)