Compact Screw Feeder to Fit Confined Space Stillwater Mining in Columbus, MT

General Description

Stillwater Mining Company operates a large mine near Columbus, MT where palladium and platinum is mined. As the only producers of palladium and platinum in the US, Stillwater Mining Company is actively involved in all aspects of mining and marketing of platinum group metals or PGMs from a geological formation in the Stillwater igneous complex in south central Montana.

Screw conveyors and feeders are used in many of the processes to mine and refine palladium and platinum. These screw conveyors and feeders are built for the mine-duty environment. Stillwater Mining needed a heavy-duty screw feeder to remove rock slag that continually spilled from a belt conveyor. The new screw feeder was located very close to a wall in a confined space and required to meter large rock chucks. KWS had the privilege of designing and manufacturing the unique screw feeder for a difficult application. Working together, Stillwater Mining, Motion Industries and KWS solved the bulk material handling problem for this one area of the plant.

Design Parameters

1. Product Type: Rock Slag
2. Material Density: 60 Lbs. per Cubic Foot
3. Conveyor Capacity: 3,180 Lbs. per Hour
4. Duty: 24 Hours per Day, 7 Days per Week

KWS Advantages

KWS chose a shaftless screw feeder for the application due to space constraints. Engineers from KWS modeled the new shaftless screw feeder as well as the surrounding area in Inventor 3D to make sure the unit would fit in the area provided. Because of the tight fit, the new KWS shaftless screw conveyor had to be maintenance-free. KWS provided a design with the least number of parts. KWS provided drawings for approval to allow Stillwater Mining to review the design and make sure the design met all the requirements of the process.

Special Features

Since space was limited, KWS provided a shaftless screw feeder and eliminated the need for a tail bearing, shaft or seal. The KWS-350 shaftless spirals are the strongest, hardest and toughest in the industry and perfect for conveying rock slag. The shaftless screw design will not clog or bind because of the open space between the flights. The new KWS screw feeder metered rock slag to a belt conveyor through a split tubular housing lined with 3/8-inch thick xylethon liners. Xylethon is an engineered plastic that has a molecular structure that makes it very dense, tough and self-lubricating. The liners are very abrasion resistant when metering abrasive rock slag.