A method for producing Portland cement clinker at low temperatures between 1250 and 1300°C, including the stages of: a) preparing a raw meal based on the Lime Saturation Factor, the Silica Module and the Alumina Module and the adjustment of the fineness of the raw mixture, with the LSF being less than 1, the SM between 2 and 3 and the AM between 0 and 3, and the adjustment of fineness must be approximately 80% of the fineness in a mesh n.200 (approximately 75 microns); b) feed the raw meal; c) preheat the raw meal; d) calcinate the preheated raw meal; e) sinter the calcinated raw meal in order to produce Portland cement clinker; and f) cool the cement clinker; This process is characterized by the following: the control modules in stage a) for preparation of the raw meal are based on the sulfur content of the solid fuel that will be burned and fixed in the calcinated raw meal; the raw meal does not include sulfated compounds, instead it contains an agent that is added in order to encourage the formation of clinker phases in the raw meal before step b) feeding; and the operating parameters of the kiln are controlled as followed: i) Residence time of the raw meal in the kiln; ii) SO 3 and O 2 at the inlet of the kiln in order to ensure the oxidation of the sulfur compound created by the fuel with a sulfur content of at least 6.5%; iii) CO at the kiln inlet less than or equal to 500 p. p.m.; and iv) Temperature in the kiln between 1250 and 1300°C; in order to allow, if not total, at least increased fixing of the sulfur generated by burning solid fuel in the calcinated raw meal such as CaSO 4 in order to create new additional phases. a) preparing a raw meal based on the Lime Saturation Factor, the Silica Module and the Alumina Module and the adjustment of the fineness of the raw mixture, with the LSF being less than 1, the SM between 2 and 3 and the AM between 0 and 3, and the adjustment of fineness must be approximately 80% of the fineness in a mesh n.200 (approximately 75 microns); b) feed the raw meal; c) preheat the raw meal; d) calcinate the preheated raw meal; e) sinter the calcinated raw meal in order to produce Portland cement clinker; and f) cool the cement clinker; the control modules in stage a) for preparation of the raw meal are based on the sulfur content of the solid fuel that will be burned and fixed in the calcinated raw meal; the raw meal does not include sulfated compounds, instead it contains an agent that is added in order to encourage the formation of clinker phases in the raw meal before step b) feeding; and the operating parameters of the kiln are controlled as followed: i) Residence time of the raw meal in the kiln; ii) SO 3 and O 2 at the inlet of the kiln in order to ensure the oxidation of the sulfur compound created by the fuel with a sulfur content of at least 6.5%; iii) CO at the kiln inlet less than or equal to 500 p. p.m.; and iv) Temperature in the kiln between 1250 and 1300°C; in order to allow, if not total, at least increased fixing of the sulfur generated by burning solid fuel in the calcinated raw meal such as CaSO 4 in order to create new additional phases. i) Residence time of the raw meal in the kiln; ii) SO 3 and O 2 at the inlet of the kiln in order to ensure the oxidation of the sulfur compound created by the fuel with a sulfur content of at least 6.5%; iii) CO at the kiln inlet less than or equal to 500 p. p.m.; and iv) Temperature in the kiln between 1250 and 1300°C; in order to allow, if not total, at least increased fixing of the sulfur generated by burning solid fuel in the calcinated raw meal such as CaSO 4 in order to create new additional phases.