(513b) A New Approach for Magnetic Separation

Magnetic separation is a very old separation technology, which is mainly used, in the mineral industry. In these applications, the magnetic force is applied to separate magnetic from non-magnetic materials. The separation efficiency strongly depends on the magnetic properties of the materials as well as the particle sizes. This paper introduces a totally new magnetic separation process, which combines aspects of magnetic separation with aspects of cake filtration. It describes the phenomenology of this new hybrid separation process and points out various fields of applications. The experimental results presented in this work show the significant influence of a superposed homogeneous or inhomogeneous magnetic field on the filtration performance of inorganic iron oxide pigments. The reason can be seen in magnetophoretic effects as well as magnetic field enhanced structure changes of the filter cake. These mentioned effects result in a faster cake formation, a higher permeation rate through an already built filter cake and therefore an integral improvement of the overall cake filtration process. Next to the extensive experimental results this work also introduces a theoretical approach for the description of the cake formation with superposed magnetic fields. In addition, the work discusses scale up related issues and other potential hybrid separation processes using magnetic fields.