選鉱過程におけるマイクロプロセスについて (2)

抄録

The turbulent characteristics in flotation machines were recently measured and the turbulent fields were confirmed to be isotropic except the impeller zone. Thus the isotropic turbulent theory was applied to determine the local distribution of the turbulent time and space scales and to analyze the energy propagation. It was also confirmed that mineral particles damped and air bubbles enhanced the turbulent motion in flotation machines.
The turbulent motion of particles must be one of the most important factors that decide the micro-processes of the flotation proce SS. Hitherto the equation of the tumbulent motion of pamticles has been analytically or numemically solved only for a mono-dispersed system. The results revealed that particles in flotation machines were able to be considered to move approximately with the fluid surrounding them under conventional flotation conditions.
The collision process between mineral particles and air bubbles must be elucidated in order to build a micro-process model for a flotation process. This problem has been tried to solve using similar methods as for coagulation problems and a few studies were reviewed.
The micro-processes in classification and thickening processes have been studied with equations of diffusion and the diffusion coefficients have been given by spatially average values. However a study that the turbulent characteristics were measured in a hydrocyclone showed that the turbulent diffusion coefficient was spatially distributed.
The study of the micro-processes in mineral processing is now progressing and there are many problems to be solved.