Process for producing a cement clinker at low temperature

(22) 08.06.2016

(43) 13.12.2017

(57) The invention provides a process for producing a cement clinker comprising: (i) mixing one or more starting materials providing each at least one or more of CaO, SiO₂, Al₂O₃, and Fe₂O₃; and, optionally, SO₃, to form a raw meal comprising CaO, SiO₂, Al₂O₃ , and Fe₂O₃; and, optionally, SO₃, wherein the molar ratios among the aforementioned oxides is given by Formula I: (CaO)₁(SiO₂)_a(Al₂O₃)_b(Fe₂O₃)_c(SO₃)_d, wherein: „a“ is comprised from 0.05 to 1, „b“ is comprised from 0.1 to 0.6, „c“ is comprised from 0.001 to 0.25, and „d“ is comprised from 0 to 0.3; (ii) heating the raw meal by irradiating with microwaves during 15 min to 3 h to reach a sintering temperature comprised from 300 to 950 °C; (iii) maintaining the microwave sintering temperature of step (ii) during 1 min to 3 h by further irradiating with microwaves; and (iv) cooling the clinker obtained in step (iii).

(71) Fundación Tecnalia Research & Innovation, 48160 Derio - Bizkaia (ES)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES Fl FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR; Designated Extension States: BA ME; Designated Validation States: MA MD