(General Information Release January 2003)

With the invaluable assistance of UK Coal and CIBA Specialty Chemicals we spent several weeks testing the performance of our steel belt filter at Maltby colliery last year. The model we used is the SBF950 which is about a quarter size unit with a belt width of 950mm. In general we expect the full size units (2.4m width) to have a capacity at least 6 times of this unit.

The SBF 950 was installed in the floor sump area of the flotation plant and a temporary feed facility was arranged from the operating RVF (rotary vacuum filters) for froth fines (<150 micron) and with the use of a mobile bowser for thickener tailings.

Key objectives were to verify scale-up predictions for filter cake capacity and to determine the filtrate and cake qualities. It has to be said that the contribution of the CIBA polymer dispersion and conditioning was fundamental in producing asonishingly clear filtrates, and biscuit like cake from the press section. It was clear too, that the performance was consistent and reproducible, once the correct flocculant conditions were realised. Despite the ridiculously low energy input and because of large mesh apertures the water removal rate was exceedingly high. Some typical results…..


Froth Fines Tailings
Throughput (dry solids) kg/h 1 – 1.5 2 – 2.5
Filtrate quality mg/litre <100 <100
Cake moisture % w/w 23 – 25 29 – 36
Combined reagents (dry basis) g/tonne 500 – 600 450 – 500


Low power VS motors

Low vacuum venturis

High pressure belt wash

Stainless steel mesh