Milling is the reduction of larger sized solid substances into smaller sizes by the use of various mechanisms. Size reduction occurs through particle-particle interactions, particle-wall interactions, and particle-milling media interactions depending on the milling machine used. The different types of mill include ball mills, air jet mills, impact mills, and roller mills. The typical particle breakage methods involved are impact, shearing, crushing, attrition or a combination of them.
The main problems associated with milling are the inefficient use of energy, and the effect of milling on the material properties. A very small amount of the input energy goes into the breakage of the substance. Energy is lost through heat, friction, noise, and plastic deformation. Material properties such as hardness, reflectivity, composition, and flowability can all be changed through the course of milling.
Within the research group we currently have access to the following types of mills:
We are currently investigating the grindability of crystalline and amorphous solids, associated structural changes and physical, chemical and mechanical transformation that are induced. The energy utilisation of planetary ball mills is being investigated using silica, with there being further investigation into the final structure of the silica after milling. We are also carrying out numerical simulation of a spiral jet mill by DEM and CFD method.