Transfer of abrasive tailings through long distance pipelines

Jon Lawson

At the KCM copper processing plant in Chingola, Zambia, classified copper tailings from a thickener and cyclone installation have to be transferred over a distance of 3.5 km to an underground mine where it will be backfilled. The quantity of dry solids is 70 ton per hour.

An ABEL triplex single acting piston diaphragm pump (HMT) was installed for the transfer of these tailings. The solids concentration in the slurry is 50%.

The quantity of slurry is 90 m³/ hr (390 GPM), the required pressure to cover the 3.5 km distance is 50 bar (725PSI).

Since start up of the pump the operating costs have been extremely low: Due to the high efficiency of the HMT, the absorbed power at 90 m³/hr (390GPM) and 50 bar (725PSI) is less than 160kW.

The spare parts consumption of the HMT, is limited to the exchange of the valves every 5,000 to 7,000 hours.

The diaphragms are replaced every 12,000 to 16,000 hours for preventive maintenance.

ABEL piston diaphragm pumps offer low operating costs due to the physical separation of the abrasive slurry from the pump’s main moving parts by pre-moulded rubber diaphragms.

Only the product valves on the suction and discharge side and diaphragms are in direct contact with the slurry. The reciprocating principle of the piston diaphragm pump ensures a very high mechanical efficiency of >93%.

Consequently, the pumping costs are minimal and make the operation of this type of pump very feasible when compared to more conventional methods of slurry transfer.

The investment in a piston diaphragm pump needs to be protected against a number of potential risks.

In the ABEL pump therefore, the gears are forced lubricated in order to enable low stroke rates. Also the pistons are lubricated to avoid overheating. The pump diaphragms are protected against overstretching by a reliable mechanical stroke monitoring system.

In addition, the pumps are equipped with pulsation dampeners which dampen pressure fluctuations, thereby protecting the pump and the piping system.

In addition to tailings transfer, ABEL piston diaphragm pumps are also being used for other applications in the mining, mineral processing and power industry, such as:

* Ore concentrate pipeline transfer

* Mine dewatering and desludging

* Mine backfilling

* Autoclave and digester feeding

* Fly and bottom ash transfer

* Filter press feeding.

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