:: Mobile Diamond-processing Plant for Namibian Resources

A Bateman trailer-mounted, modular processing plant has been delivered to Namibian Resources for use at their alluvial diamond-mining concession, south of Luderitz.

The contract included the design, manufacturing, supply and delivery of a 10 t/h dense-media separation (DMS) plant, an X-ray recovery unit and a front end. The 10 t/h DMS plant is mounted on a 12 m trailer for easy movement from site to site. The motor control centre (MCC) is fixed on the main structure where a diesel driven generating set will be mounted in front of the MCC. The plant was delivered to the concession from Johannesburg by road and was designed so that it could be easily disassembled for ease of transport and would comply with road ordinance regulations. The entire plant, which weighs some 12,5 t, can be made ready within one day for relocation from one site to another and can also be easily converted to a fixed installation on a concrete base if the need arises.

Washed gravel (of size range +1,5 mm to -12 mm, equivalent to a ±24 carat diamond) from the modular pre-treatment plant is fed into the DMS feed bin using a front-end loader. The gravel passes via a pan-feeder onto a conveyor which feeds the DMS plant.

The DMS concentrates discharge into specially-designed stainless steel bins. These bins have a three-hour capacity and, when full, are lifted by chain hoists onto a truck for transport to the recovery unit which is located 86 km from the mining site. At the recovery plant, the concentrates are discharged onto a sizing screen for sizing and a tube feeder feeds these fractions separately to the wet X-ray recovery unit.

To obviate the need for separate transport arrangements, the DMS has its own generator set which is mounted on a platform above the rear wheels of the trailer, together with the MCC. The trailer has a dolly wheel to enable it to be pulled by various means including front-end loaders, graders or tractors.

Due to the aggressively corrosive climate on the West Coast all steelwork, including the trailer, had to be painted to a special marine specification to protect it from the extreme conditions such as salt-laden fog and high winds.

The order was received in June 2004. The design, manufacturing and supply of the plant were completed within three months. The complete plant was manufactured, pre-erected and water tested at the works in Gauteng. The erection of the plant, on site, and commissioning were achieved in less than one week. Bateman engineers were on site in Namibia both for the commissioning of the plant and training of the operating staff.