Ceramics-Silikáty 59, (3) 220 - 226 (2015)

In this paper, the effect of MgCl₂ addition on the synthesis of hercynite was investigated. For this reason, hercynite was prepared by co-precipitation of AlCl₃∙6H₂O and FeCl₂∙4H₂O along with various amounts of MgCl₂ at 60°C. Then, the co-precipitated materials were calcined at 1300, 1400 and 1500°C in air atmosphere. Afterwards, phase composition and microstructure of samples were studied by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The results showed that the formation of hercynite simply took place with the presence of MgCl₂ due to the release of Mg²⁺ cations and then, the formation of spinel structure and its evolution to hercynite structure. Moreover, the addition of MgCl₂ influences the amount of hercynite phase. Calcination temperature affects hercynite crystallite sizes so that hercynite crystallite sizes increas by the increasing of calcination temperature from 1300°C to 1500°C.