The work performed in this thesis was aimed at evaluating the influence of lifter face angle on the charge kinematics for a laboratory scale mill. The study involved tracking a single particle representing the ensemble using the Positron Emission Particle Tracking (PEPT) to obtain the location of the particle with time. The particle was radiated with a radionuclide; 68Ga, which has a half-life of 68 minutes. The objectives of the study involved tests with different lifter face angles at different mill speeds and volumetric mill filling. After performing the tests the data was analysed to obtain probability density distributions for each test conditions from key charge descriptors. Charge descriptors such as the Centre of Circulation (CoC), shoulder angle, toe angle, the free surface and also kinematic information such as the velocity profile along a carefully chosen radial line from the centre of the mill that passes through the CoC were obtained. The time averaged velocity data was used when assessing the influence of the lifter face angle on the velocity profile. The results showed notable effects of lifter face angle on charge characteristics. No real definitive trend was observed for the CoC as the lifter face angle was altered at all mill speed and filling conditions. However, the CoC showed an outward shift toward the mill shell with an increase in mill speed but an inward shift toward the mill centre with increase in charge filling degrees. Mill speed is expected to cause a load expansion as the charge approaches centrifugation. The shoulder angle showed a general increase as the lifter angles became steeper for both an increase in mill speed and charge filling degrees. The impact toe angle displayed maxima with increasingly steeper lifter face angle depending on the condition altered. At the higher mill speeds (70 and 85 % of critical speed), the impact toe did not show as much variation with lifter face angle. However, a noticeable difference was observed at the lowest mill speed tested; which was 55 % critical speed. At 20 % charge filling degree, the impact toe increases from 45 to 90 ° lifter. At the higher filling degrees, a maximum was reached from 45 to 75 ° lifter and from 75 to 90 ° a decrease was seen. It is expected that the steeper lifter angles will cause the charge to impact the mill shell as the lifting forces are altered. The velocity profile demonstrated changes with face angle as distances along a radial line in the mill were investigated. As the speed was increased from 55 to 85 % of critical speed, the velocity profile showed minimal changes for the higher mill speed at distances closest to the mill shell, and more perceivable changes in the profiles at 55 % of critical speed for all radial distances investigated.

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