COMPLEX OXIDES OF THE CALCINED SPINEL AND THE METHOD OF ITS PRODUCTION Russian patent published in 2007 - IPC C04B35/443 C04B35/42 

FIELD: production of the complex oxide of the calcined spinel.

SUBSTANCE: the invention is pertaining to production of the complex oxide of the calcined spinel, which is used for the water-holding and well- drained artificial fillers. The complex oxide of the calcined spinel is produced by calcination of the mixture containing the slag being the by-product of the chrome purification process, the reducing agent and the silicon dioxide-containing material, and in essence consists of the following components (in mass %): 29-40_{Fe2O3, 15-20А12О3, 9-14 MgO, 0-4Na2O, 9-17Cr2O3, 14-20 SiO2 and 2 or less СаО. The complex oxide of the calcined spinel gives Cu-Kα X-ray diagram, on which the ratio of (b/a) intensity of the diffraction peak containing the silicon dioxide of material(b) near to 2θ = 26.7° to the intensity of the diffraction type plane {113} (a) near to 2θ =36° makes 0.1 or less. The method includes production of the mixture of the indicated components, its granulation or pressing and calcination at the temperature of 950°С and more. The technical result of the invention is production of the heat-resistant and capable of being reused material, from which chromium and alkaline components are not leached even in the severe conditions.}

EFFECT: the invention ensures production of the heat-resistant and capable of being reused material, from which chromium and alkaline components are not leached even in the severe conditions.

13 cl, 6 ex, 18 tbl, 2 dwg