Inducible regulation of spherical CaO particle for the recycling of carbide slag

Various factors affecting the high temperature compressive strength (TCS) for the carbide slag-based CaO pellets were systematically examined both experimentally and theoretically. It showed that the spherical CaO particles with microstructure can enhance the TCS of the pellets, and the higher the spheroidization of the particles, the higher the TCS. Inducing H 3 BO 3 can lead to a low-temperature nucleation of CaO particle, inhibit the growth of CaO grain, and thus form spherical CaO particles. The TCS of CaO pellet from Ca(OH) 2 was optimized with the response surface methodology with a highest value of 37.4 MPa. For the CaO pellet from the carbide slag, the TCS under optimal conditions was 39.67 MPa. However, it was found out that an excess of H 3 BO 3 inducer in the CaO pellets from the carbide slag could produce eutectic calcium borate with a low melting point, resulting in a decreased TCS.