Dowding Reynard & Associates (DRA) has developed a mobile dense-media separation plant that is capable of recovering diamonds and diamond-indicator minerals as small as 300 microns from prospecting samples. The plant is designed around a small gravity-fed cyclone which is fed by a seamless mixing box. The plant is built into a 6 m shipping container with a reinforced roof, which acts as a work platform. The unit can recover heavy minerals and diamonds from prepared samples (loam, stream sediment, or crushed rock) in two sizes ranges: from around 1 mm to 6 mm, or 0.3 mm to 2 mm. The actual plant consists of a feed hopper with vibrating feeder; a mixing box and cyclone; a combined product screen with woven-wire screen cloths; a separate concentrate screen with removable sieves; a circulating medium pump; a dilute-medium pump; a wet-drum magnetic separator; a magsep effluent sump and pump; a medium holding tank with agitator; a demagnetising coil; a density control system and a chart recorder.

The Micro 'Plus' version of the plant includes sample preparation equipment including: a feed preparation screen, mixing box and a cyclone-feed pump which are also located in the container, and a separate, skid-mounted 'front-end' consisting of a feed conveyor; a rotary scrubber with a trommel screen; a scrubber-product sump and pump; a jaw crusher and a DMS tailings conveyor.

Contact:
lan Gilbert
Dowding Reynard & Associates
Tel: +27 (0)11202 8600. Fax: 202 8804
iang@
draprocess.co.za

Source:
Mining Journal, July 5, 2002, p.7