An increasing number of brownfield expansions are being undertaken by surface mines in Africa in an effort to boost production while reducing risks and costs compared to new greenfield projects. Minerals and mining technology specialist Weir notes that this has translated to a rising demand for high-capacity vibrating screens to enable high-throughput operations, as well as machines with a wider operating window to address changing feed conditions.

The launch of its new ENDURON vibrating screen ranges is a direct effort by Weir to address these market trends and requirements. 

According to Weir global product manager: vibrating screens Corné Kleyn, key trends currently shaping the vibrating screen market in Africa include the need for high-capacity machines for brownfield expansions, demand for screens with a wide operating window to meet changing feed conditions and a growing focus on screen designs that minimise energy consumption and reduce wear and tear to ensure sustainable operations.

These trends, says Kleyn, were central to Weir’s design approach to its new ENDURON Orbital and ENDURON Elite vibrating screen ranges. The high-capacity nature of the ENDURON Elite range aims to address the growing need for high-capacity vibrating screens for brownfield expansions, especially as opencast mines seek to ramp up production.

“With the launch of the ENDURON Elite vibrating screen range, Weir now offers some of the largest double-deck banana screens in the world, weighing up to 50 t. Some of the first units operating in an iron-ore application in West Africa measure 4.3 m wide x 9.7 m long, highlighting the large nature of these screens that address high throughput needs,” Kleyn notes.

One of the design features of these screens is the ETX exciters. Capable of driving a vibrating screen with a deck that spans 4.27 m, these exciters are said to have the largest capacity of any exciter currently available on the market. Their large size allows the large Elite vibratory screens to be driven with two exciters, reducing exciter drive complexity and maintenance costs. This aims to ensure high performance and long service life. In addition, fewer exciters are required on site –leading to reduced downtime, routine inspections and inventory management.

As mines expand and get deeper, changing feed conditions, such as variations, and the efficiency and cost effectiveness of mineral processing operations, can be significantly impacted, says Kleyn. When feed conditions change, he adds, screens are subject to harmonic resonance which can lead to structural failure. To mitigate against this, Weir has designed both its ENDURON vibrating screen ranges with a wider operating window, giving operators greater flexibility to adapt operating parameters as feed conditions change.