Manual Pinch Valves

Red Valve Company, Inc. • 600 North Bell Avenue, Carnegie, PA 15106 • 412-279-0044 • Fax 412-279-7878 • www.redvalve.com

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MiningType A Pinch Valve Ideal for Tough Copper Mining Slurry

Mining

Copper mining is one of the most difficult slurry-han-dling applications. When copper is lifted from theground, it is embedded in a rock that must be brokenapart in order for the copper to be extracted. For everysmall amount of copper that is produced, a largeamount of over-burden is left behind. This materialforms a thick, weighty and highly abrasive sludge thatmust be transported from the flotation cells, where thecopper is extracted, to a mine tailings disposal area.

The Chuquicamata Mine, the world’s largest coppermine located in Codelco, Chile, was experiencing majordifficulties with short service lives on the control valvesthat were being used in this disposal process. As in mostapplications where thick slurries are being handled, theChuquicamata Mine’s pipelines are oversized to allowfor a faster rate of flow. Therefore, an oversized controlvalve in the pipeline must always be positioned at morethan 50 percent closed for proper control accuracy,causing a high pressure drop followed by a severe rateof recovery, which results in damaging cavitation.Furthermore, increased velocity at the valve’s throttlingpoint can quickly erode standard metal valve bodies.

The Chuquicamata Mine found the answer in Type AControl Pinch Valves from Red Valve. Each Type Ainstalled at the Chuquicamata Mine is equipped withRed Valve’s patented cone sleeve, a sleeve designed toreduce pressure across the downstream side of the valve

and maintain a low recovery factor, eliminating cavita-tion. Like all Red Valve pinch sleeves, the cone sleeveis constructed entirely of abrasion-resistant elastomerand is the only wetted part of the valve. The sleeve willoutwear any valve on the market and is easy and inex-pensive to replace. The area where velocity increases isstrengthened with extra material, which further protectsagainst the destructive abrasiveness of the copper minetailings.

Pleased with the results, the Chuquicamata Mine lateropted to install the Type A on its water reclamation sys-tem. Before the slurry is discharged to the disposaltank, it is sentto a thickenerthat extractsthe water forreuse. Thesludge beingp u m p e dthrough thepipelines after the water has been extracted is highlysolidified and even more abrasive than before. It isimportant that the valves in these tough conditions areextremely reliable so that water, a limited and expensiveresource for mining companies, can be efficientlyreclaimed.

To further reduce pressure recovery and cavitation in itswater reclamation pipelines, the Chuquicamata Mineinstalled a Red Valve TF-O Variable Orifice FlowRestrictor downstream of each Type A Control Valve.The TF-O decreases pressure in the line, forcing back-

pressure onto the dischargeopening of the control valve.This backpressure offersadded protection against cavi-tation and valve wearing.

Chuquicamata Mine, Codelco, Chile

Type A in operation on water reclamation system

The TF-O Flow Restrictor is installed downstream of the Type A