WATER MANAGEMENT
without their shortcomings. In several applications, rotors or impellers on slurry pumps last only weeks and diaphragm pumps clog, leak or fail in a matter of months. Attempting to overcome these problems, some mine operators previously purchased special pumps constructed from acid-resistant materials rather than put up with frequent, costly pump maintenance or replacement. But this is an expensive alternative. For these reasons, the latest peristaltic (hose) pumps are today taking ever greater slices of market share. Among the many benefi ts of peristaltic pumps are: few moving parts; low and easy maintenance; can pump almost all materials, including slurries; zero contamination; and wear-free performance. For the mining sector this last point is the most advantageous. T e wear-free performance of peristaltic pumps is an attribute that results from a unique operating principle. Unlike other pumps, the abrasive nature of the product has no bearing on pump life and the need for routine maintenance and spare parts is greatly reduced. In a peristaltic pump nothing but the hose touches the fl uid, eliminating the risk of the pump contaminating
Jaguar Mining uses Bredel pumps at its mines in Brazil
the fl uid, or the fl uid contaminating the pump. Fluid is drawn in and trapped between two shoes before being expelled. T e complete closure of the hose, which is squeezed between a shoe and the track, gives the pump its positive displacement action. T e result is a pump ideally suited for the transport of typical mining slurries including pyrite, copper, zinc, uranium, nickel, cobalt, silver, platinum, lime and gold concentrate.
SAVING WATER IN THE STATES O
ne recent benefi ciary of peristaltic technology
is a large copper and gold mining company in Arizona, USA, which had to frequently replace components on hard chrome iron centrifugal pumps used in a diffi cult tailings slurry application. The pump impellers were wearing out every two weeks, causing considerable downtime and costly repairs. The mine considered several
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diff erent pump technologies, fi nally selecting Bredel 100 hose pumps. In this application, the hose pumps transfer tailings slurry 670m to a separate plant. With no seals to fl ush and the ability to pump tailings with a high solids concentration (80%) the mine uses much less water with the hose pumps, providing considerable savings in both maintenance costs and water usage.
Pumps such as the Bredel range are
virtually maintenance-free as there are no impellers, liners or mechanical seals to replace, no check valves to clog and no rotors or stators to wear out. T e only wear-part is the hose, which can be replaced in a matter of minutes with no special tools. T e hose is the secret at the centre of peristaltic technology. T is is the part in direct contact with the slurry – so it needs to be both fl exible and tough. At the heart of all Bredel pumps is a composite reinforced hose constructed from compounded rubbers reinforced with four individual layers of braided nylon, and fi nished by precision machining for enhanced suction, pressure and fl ow performance over the life of the hose. Features such as these are
important because over-occlusion of the hose stresses both the pump and hose, reduces hose life, and places unplanned loads on the pump bearings. Similarly, under-occlusion results in loss of pump effi ciency and damaging back-fl ow, which also reduces hose life. More and more mining industry customers are turning to peristaltic
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