Weir Minerals Africa is poised to ship a substantial order for a complete cyclone package — designed in Africa for Africa — to First Quantum Minerals’ new Sentinel copper project in Zambia. First Quantum is a major and longstanding client of Weir Minerals Africa, both in Africa and across the world, in areas such as Australia, Finland and Central America.
This will be one of the biggest installations of its kind ever supplied by Weir Minerals Africa into an African application and includes six cyclone clusters. To date, clusters of this size only occur in Australia and Chile. The equipment destined for the Sentinel project is considered very large for any greenfields project and is at the upper end of global engineering practice.
The Sentinel copper project at Kalumbila, some 150 km west of Solwezi in northwest Zambia, is part of the Trident project that includes the Enterprise nickel project and several other exploration undertakings. The Sentinel project is being developed by Kalumbila Minerals, a wholly owned subsidiary of First Quantum Minerals.
The order was placed with Weir Minerals Africa in mid-2012 and the cyclone clusters have been custom designed for this application to achieve a specified metallurgical performance. Commissioning is scheduled for the first quarter of 2014.
Weir Minerals Africa’s process manager, JD Singleton, says he believes the company was preferred in its bid to supply this equipment based on its unique Cavex® technology and associated application skills, as well as its quick response time to technical queries during the tender adjudication period.
“In addition to our proprietary Cavex® technology which is well proven in the Zambian copperbelt, other unique features of this order include various grades of Linatex® rubber lining for superior abrasion resistance and our Isogate® knife gate valves with full port flow which will ensure that the Cavex cyclones receive a laminar feed,” says Singleton.
The package includes two clusters for the SAG mill operation, each of which comprises 12 x 650 CVX cyclones (of which one will be put by for future expansion), with a capacity of more than 3,000 m3/h, and four clusters for the ball mill, comprising 16 x 650 CVX cyclones with a capacity in excess of 5,000 m3/h.
For all Weir Minerals Africa-supplied clusters, it is standard practice for the technical team to conduct a complete dummy assembly prior to the application of rubber linings, to allow for final modifications. This practice is also included as a standard holding point in the company’s quality control programme and is witnessed by the customer.
Weir Minerals Africa will provide commissioning assistance on site and will support its equipment for the life of the mine from its Zambia branch, including stockholding of spare parts, with backup from the company’s Isando operations. The clusters are 100% locally designed and fabricated by Weir Minerals Africa.
The unique laminar spiral inlet geometry of Weir Minerals’ Cavex hydrocyclones has been fundamental in helping drive customer productivity upwards whilst also bringing down the total cost of ownership, it reports. The Cavex hydrocyclone represents an entirely new feed geometry that substantially increases hydraulic capacity while minimising localised wear on the feed chamber and vortex finder. This effectively lowers operating costs and minimises the number of cyclones required for a given application.
The laminar spiral inlet geometry design provides a natural flow path into the Cavex hydrocyclone. Its unique shape has no sharp edges or square corners and allows the feed stream to blend smoothly with rotating slurry inside the chamber. The result is greatly reduced turbulence throughout the entire hydrocyclone creating more even wear, longer life and more efficient classification.
In conventional hydrocyclones, slurry bursts into the cylinder with no flow control and the resulting turbulence is responsible for gouging liner walls. By minimising flow resistance through the feed chamber, Cavex hydrocyclones process substantially higher slurry volumes than conventional hydrocyclones with equivalent fittings. The increased productivity effectively reduces the quantity of hydrocyclones required and minimises the energy required to perform the given duties.
