BoVac Disc Filter for Tailings Filtration
BOKELA is proud to announce the award of an order from British base metals producer Central Asia Metals PLC (CAML) for delivery of one (1) BoVac disc filter M88. The vacuum disc filter will be operated at CAML’s Sasa zinc and lead mine in North Macedonia to produce a paste from concentrator tailings for mine backfill. The scope of delivery also includes various ancillary units such as vacuum pump, filtrate receiver, blower and blower tank.
Sasa mine is changing its mining method from a sub-level caving method to a cut and fill stoping method in order to improve its tailings disposal management, reduce its environmental impact, enable safer operating practices and to maximise the recovery of mineral resources. The new cut and fill method involves filling of mined voids with a backfill paste material. For this reason a backfill plant is being built in which tailings from the ore processing facilities will be dewatered to a solids concentration of < 80% solids and then mixed with cement, fly ash and water to produce a backfill paste of the appropriate consistency. This will eliminate the need to construct further tailings dams in the future (Read more: https://www.centralasiametals.com/operations/sasa/)
CAML decided in favour of the BoVac disc filter technology for tailings dewatering in its new backfill plant because of the high throughput and reliable dewatering performance of these modern vacuum disc filters combined with high operational reliability even with different feed conditions and ease of maintenance. Due to these properties, the modern BoVac disc filter technology only needs half the filter area that would have been required by competitive disc filter technology to cope with tailings dewatering at the Sasa mine. Reference visits to two processing plants that use BoVac disc filter technology for the filtration of their tailings were the last impetus for CAML to also decide in favor of this modern disc filter technology.
The BoVac disc filter is designed to filter 80 t/h solids with a filter cake moisture of 17 wt.-%. For the dewatering of this tailings slurry, it is crucial that a consistently low cake moisture level is achieved, which enables the exact dosing of a reasonable amount of cement, fly ash and water to keep operation costs low.