Magnetic separation trials for clarification of radioactive liquor using chromium powder simulant

This paper describes a series of trials to assess the use of HGMS in nuclear fuel reprocessing, by using chromium as a nonactive simulant. The magnetic filter used was in the form of 3 mm diameter balls. Filter performance was measured at magnetic field levels between 0.8 Tesla and 1.7 Tesla and at flow velocities between 0.6 cm/sec and 1.6 cm/sec. These show that 98% of the suspended solids can consistently be removed under these conditions, and that the filter can trap at least 7% of its own weight of solids. Data were obtained on the variation of trapping efficiency with particle size. The pressure drop across the filter was shown to be a sensitive function of filter loading and trials were also made to determine the optimum method of unloading the filter. The present status of a supporting work programme to fabricate and test a corrosion resistant magnetic matrix is reported.