Solventless Mechanochemical Synthesis of Phase Pure Syngenite

Syngenite (K2Ca(SO4)2 ⋅ H2O) presents an effective hydration activator (accelerator) for anhydrite (CaSO4) applied in construction systems. The current synthesis relies on co-precipitation of K2SO4 and CaSO4 2H2O produces large amounts waste water holding excess potassium sulfate. Therefore, this method is deemed ineffective, uneconomical environmentally unfriendly. Moreover, it crystals (ℓ ∼5-30 μm) which are less as nucleation seeds gypsum crystallization. In study, a novel, solventless mechanochemical process proposed simple, eco-friendly reproducible large-scale production sub-micrometer sized syngenite different morphology high purity strongly promote to gypsum. Optimal conditions the were determined, products obtained characterized via X-ray diffraction, IR spectroscopy, thermogravimetry SEM imaging. optimized product was compared with from co-precipitation, structural differences discussed its superiority seeding material evidenced.