Use of celesto-barite mine waste in the production of eco-friendly white cement

This study aims to produce an eco-friendly white cement clinker by incorporation of celesto-barite mine waste. Samples of synthesized pure Monoclinic-C3S, Cubic-C(3)A and raw-mix were dried, ground to a Blaine of 3200cm(2).g(-1), doped separately with crescent amounts of mine waste and pure BaO (5 and 3% respectively), then burned at increasing temperature levels (1300-1400 degrees C). The effects of mine waste and BaO on raw-mix and synthesized pure clinker phases in terms of burnability, ultra-features, chromaticity, and mechanical strength of the synthesized clinkers were discussed through several techniques, including XRF, XRD coupled with Rietveld refinement, Thermal Analyses and SEM combined with EDS. Results reveal that incorporating 3% of mine-waste between 1350-1400 degrees C allows the production of high-quality belite-rich clinker for white cement (45.4%-C2S), with improved raw-mix reactivity and burnability by accelerating Free-lime absorption. Mechanical and colorimetric performances of cement were equivalent or better than the reference. The manufactured clinker bears relevant environmental and circular economy benefits by limiting greenhouse emissions, recycling mine-wastes and producing an eco-friendly and low-cost binder.