CHROMOUS CALCIUM HEXAALUMINATE-BASED REFRACTORY AGGREGATE AND PRODUCTION METHOD THEREOF Russian patent published in 2010 - IPC C04B35/44 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to refractory industry, specifically to a refractory aggregate based on chromous calcium hexaaluminate and a method of producing said aggregate from high-alumina slag from aluminothermic production of chromium metal. The said refractory aggregate can be used in production of unmoulded refractories and refractory articles meant for lining thermal generating units in various industries. The chromous calcium hexaaluminate-based aggregate contains the following mineral phases in wt %: chromous calcium hexaaluminate CaO·6(Al,Cr)₂O₃ 86.0-94.0, chromous corundum (Al, Cr)₂O₃ 1.5-10.0, Mg(Al,Cr)₂O₄ spinel 2.0-4.0, calcium dialuminate CaO-Al₂O₃ 0.1-0.5. Method of producing the chromous calcium hexaaluminate-based refractory aggregate involves processing high-alumina slag from aluminothermic production of chromium metal through further roasting at 1500-1750°C and crushing it to given grain composition.

EFFECT: volume constancy of the aggregate at temperatures higher than 1400°C, which enables its use at higher temperature.

2 cl, 1 ex, 2 tbl