EFF ECT OF CEO2 ON THE CRYSTALLINE STRUCTURE OF FORSTERITE SYNTHESIZED FROM LOW-GRADE MAGNESITE

Abstract

The infl uence of CeO₂ on the crystalline structure of forsterite synthesized from low-grade magneiste and natural silica is discussed in this paper. X-ray diff raction (XRD) and scanning electron microscopy (SEM) were employed to characterize the crystlline structure and microstructure of each specimen. X’ Pert plus software was used to determine the lattice parameters of each specimen. Bulk density, apparent porosity, water absorption and cold crushing strength of the test samples were tested according to standards issued by the Ministry. The resultes show that forsterite can be synthesized from low-grade magnesite and natural silica through solid reaction. appropriate CeO₂  addition is helpful to formation of forsterite. The defect caused by CeO₂ in the active magnesia accelerate the diffusion rate of ions. In combination of XRD, SEM and property analysis results, the optimal addition of CeO2 is determined to be 0,8—1,2 %, the forsterite exhibits relatively more homogeneous grain-sized microstructure, the bulk density is 2,15—1,18 g/cm3, the apparent porosity is 29,5— 30,1 %, the water absorption is 13,5—14,0 % and the cold crushing strength 13,4—14,2 MPa. Ill. 2. Ref. 16. Tab. 2.