Study On The Chrome-corundum Refractory For Ausmelt Furnace Lining

Alumina-chrome slag is produced by thermite reaction when smelting ferrochrome,which is easy to separate from ferrochrome on account of their specific gravity.It can be regarded as a good resource（chrome corundum）after simplicity in treatment,so that its treatment and utilization has attracted extensive concern and attention at home and abroad.Ausmelt furnace is a kind of matte smelting equipments in fire copper smelting process.At present,magnesite-chrome bricks are mainly used in Ausmelt furnace lining.Because of the low melting temperature,low viscosity of the slag,strong invasive and permeability,penetration metamorphic layer around the slag lining is stick and porous resulting in easily structural spall.Chrome-corundum refractories behave well in mechanical properties,elevated temperature properties and slag-resistance.Cr2O3,Al2O3 or chrome-corundum can react with FeO from slag to form compounds with high melting points which can raise the viscosity of slag and prevent the infiltration.All the excellent performances make it great significance and broad prospects on the use and resource utilization of Ausmelt inner lining bricks.In this paper,chrome-corundum,industrial chromium powder used as raw materials,while aluminium dihydrogen phosphate was employed as the binder to find the corrosion mechanism and proper preparing condition.TiO₂,ZrO₂,chrome ore were used as additives to improve the properties of chromium corundum refractory material.The performance of pilot test samples and volume production were also tested.Conclusions were obtained as follows:1.FeO from the slag react with Cr₂O₃ and Al₂O₃ to form protective layer of Iron chromium spinel and hercynite with high melting point which can prolonging servce life.SiO2 and CaOcan infiltrate through the pores and cracks to form Er silicate with Al2O3which can protect the refractories by increasing the viscosity and diminishing slag penetration.2.Chrome-corundum was used as the main raw material,proper high sintering temperature would improve the density and strength.To consider comprehensive performance,when the sintering temperature is 1600℃for 3h with 3%chromium powderof industrial use,chrome corundum bricks present good performance of compactness,strength and thermal stability.3.Addictives could improve the propertied of aluminium chromium refractories.PSZ would have a good influence on thermal resistance because of phase transformation toughening during the sintering process,while chrome ore would increase the degree of solid solution and good for density and slag-corrosion resistance.TiO₂ micropowders would accelerate sintering process and obtained a better thermal resistance.4.By testing the properties of pilot test samples and volume production,it is believed that two kinds of volume production can totally replace aluminium chromium refractory to apply in the lining of Ausmelt furnace.