Rotary disc filters use sector or disc bags, wedged shaped bags designed to fit which makes up the rotating disc. Disc filters are continuous process, vacuum filters, frequently found in the metal mining, metal ore beneficiation and coal cleaning industries.Disc filters rotate in a vat of slurry, rotate into the pan, pick up solids, dry and then release those solids. In most cases, the solids are the product, which is augured off the rotating disc by screw conveyor.