Portland cement clinker production using concentrated solar energy – A proof-of-concept approach

The aim of this work was to demonstrate the feasibility of producing Portland cement clinker upon direct exposure of the raw materials under concentrated solar radiation using the PSA high concentration solar furnace SF40. For this purpose, a short thermal cycle (<40 min) was devised including 5 min dwell times at temperatures in the range 900–950 °C and 1250–1300 °C, followed by 10–15 min at 1500–1550 °C. The chemical and mineralogical data of the grey clinker produced are encouraging since values of 51.0 ± 6.9% C3S, 22.7 ± 5.3% C2S, 8.6 ± 0.4% C3A and 10.8 ± 0.7% C4AF are similar to those observed for conventional clinker used for the production of Portland cement in accordance to EN 197-1 standard. White clinker, in turn, could not be produced by direct irradiation in this setup conditions because of its low absorptance of solar energy.