Coating Ca2+–Fe3+ co-doped LaAlO3 on high-temperature electric furnace for energy-saving

The energy-saving effect of high-emissivity coatings on high-temperature electric furnaces has not been fully explored. In this study, high infrared emissivity coatings (ε1–2.5μm, 1200 °C = 0.81) are successfully prepared using La0.9Ca0.1Al0.9Fe0.1O3 powder as radiation agent and aluminium sol as binder. The experimental results on a high-temperature electric furnace reveal that the power consumption for heating air and heating refractory bricks before and after lining coating increase by 4.7% and 5.4%, respectively. This energy consumption increase is primarily concentrated in the heating stage because the high absorption of the coating causes an increase in the heat loss of the lining. Moreover, the scheme of the high-emissivity coating application on the outer surface of a crucible is proposed. Experimental results indicate that this technique can effectively improve thermal efficiency and, therefore, can be successfully implemented in future industrial applications.