Sophie Rimmer
MEng – Chemical Engineering , University of Birmingham, 2017.
PhD with Integrated Studies Research Engineer
Sponsor: EPSRC and Imerys
School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
PhD Project Background
The grinding of minerals is a highly energy intensive operation, with large amounts of energy being lost as heat, noise or vibrational energy.
Stirred media mills are commonly used for fine grinding. They are formed of a stationary grinding chamber equipped with an agitator. The mineral is added to the grinding chamber with water, a suitable dispersant and grinding media. For a particle to break, media must collide and trap particles, with enough stress being imparted to break the trapped particle. To maximise the amount of particle breakages, both the number of collisions and the amount of stress imparted in a collision should be maximised.
The aim of this project is to determine how the optimum grinding operating conditions can be selected, enabling particles of the desired size to be produced with the lowest energy usage. Initial experiments are being conducted using a lab scale grinder. Particle Image Velocimetry (PIV) and Positron Emission Particle Tracking (PEPT) will be used with the lab scale grinder to look at flow patterns and particle velocities inside the mill and how they change with different operating parameters. Later experiments will be conducted at Imerys’ pilot plant in Belgium to look at the scalability of the lab scale grinder and determine how the optimal parameters vary between the scales.