Data for In situ X-ray scattering of the crystallisation of basic magnesium chlorides using a laboratory instrument

By simultaneous acquisition of SAXS/WAXS, time-resolved particle size and phase evolution information was obtained from room temperature to 120 C. The WAXS data were analysed using two-phase Rietveld refinements, to produce crystallisation curves.

From Avrami-type kinetic analysis two competing mechanistic processes were proposed for the formation of Mg3Cl(OH)5·4H2O with a nucleation-type mechanism extending further into the reaction with increased temperature. When comparing SAXS and WAXS, an offset between the consumption of MgO and the reduction of the sphere contribution to the SAXS scattering is observed. This is rationalised by the formation of an amorphous Mg(OH)2 layer on the MgO particle surface.