Abstract: In order to explore the feasibility of air-quenching high-temperature copper slag and investigate the influence of liquid viscosity on granulation, an experimental device was built to compare the granulation effectiveness of water, machine oil and liquid wax. The results show that the shape of liquid drops is closer to the sphere, and size distribution is more uniform with increasing liquid viscosity. Solidified wax granular has a narrow size distribution, which is beneficial for secondary the recovery of waste heat. Simulation of cooling and solidification of a single high-temperature copper slag droplet was carried out by using fluid volume function models (VOF), solidification melting model and radiation model (DO). The results indicate that the copper slag droplet with a diameter of 2 mm and temperature of 1 355 K can form a shell quickly and solidify completely after 1.62 s when cooled by air at room temperature of 300 K. The cooling rate at the windward side of the droplet is higher than the leeward side during the cooling process, which will result in uneven solidification. High-velocity airflow has a stronger cooling ability, which can lead to a faster solidification rate of the droplet. Heat transfer efficiency will be higher, and solidification time will be shortened with a decrease in initial droplet size.