MSc (Eng) Project title Understanding the hydrodynamics in a nickel reduction autoclave
(Supervisors: Prof A Lewis, Prof J-P Franzidis) Graduated: 2011
This project aimed to characterize the different impeller speeds required for attrition, breakage and suspension of nickel particles in an autoclave. This is important during nickel reduction where crystals become too large through growth and agglomeration, causing operational problems. If there is insufficient turbulent energy available in the autoclave, then it is possible that there is not sufficient shear to cause breakage of the newly formed agglomerates. The concept of attrition speed was investigated in a 7 litre Perspex reactor by way of actual impeller crystal collisions. Particle size distributions of the attrition products, expressed as number distributions, were used to identify the presence of attrition.
Paradza, N. and Lewis, A.E. (2010), “Investigating the concept of ‘just suspended’ impeller speed for a nickel reduction autoclave,” SAIMM (Western Cape Branch) Conference, Cape Town, 7-8 August 2010.