PERFORMANCE OF HGMS FILTER FOR RECOVERY OF MAGNETIC FLOCS

The performance of a parallel-stream HGMS filter is investigated for recovery of magnetic flocs in this experiment. To recover silicon oxide particles, which are non-magnetic, magnetic flocs consisting of silicon oxide particles and magnetite particles as magnetic seeding material are formed. Aluminum phosphate as a coagulant is added to flocculate. The time dependence of the accumulation area of magnetic flocs on a filter element is observed. At the same time, recovery is measured as a function of time. The accumulation area of magnetic flocs increases with time. Recovery is about 70% at pH7.4, but is 100% at pH5.0 with aluminum concentration of 0.02.kg m(-3). Recovery increases slightly with increasing aluminum sulfate concentration in the range of 0.005 to 0.025 kg.m(-3) at pH7.4. In addition, filter equations are solved numerically. The procedure of curve-fitting for solutions of filter equations to experimental results are carried out and the filter performance is found to be shown by filter equations. Also, the saturation concentrations of particles accumulated in a filter are obtained.