Analogue experimental investigation on ligament granulation of molten slag in various rotary disk configurations for waste energy recovery

•Analogue experiments of molten slag granulation in various rotary disk configurations are carried out.•A correlation for predicting the particle size for four types of disks is determined.•The majority of the particles size is populated in the range of 2.0∼4.0 mm.•The curved-block/arc-edge disks can produce particles with smaller size.•Fibers generation is determined by Q, ω and liquid film breakup model. Rotary disk centrifugal granulation is one of the most promising methods for molten slag recovery with lower power consumption, compact and coupling with a variety of waste heat devices easily. In this paper, high temperature analogue experiments were performed by four types of disks with molten aluminum as the working fluid. The particles characteristics which include particles size distribution, particles mean size and fiber mass fraction were studied. The results show that the majority of the particles size is populated in the range of 2.0 mm∼4.0 mm for all the ω and Q. Both theoretic and experimental analyses indicate that the ω has more impact on particles size than Q. The particles produced by curved-block disk and arc-edge disk configurations are more concentrated than the other two types of disks. Besides, the mean size of particles generated by curved-block disk is smaller. A simple correlation of dm for four types of disks is proposed, which agrees well with the experimental data (R2 = 0.9172). Meanwhile, when the Q is relative low, a lower ω can contribute to the reduction of produced fiber. The main conclusions drawn from this work will be helpful for future development of the high-temperature molten slag dry granulation systems.