Capital Equipment News January 2022

Leveraging research Innovations in the washing sector are helping mines and quarries overcome challenges around water management. For example, Kwatani’s research and development team made use of the latest research publications available on dewatering. “Interpretation of the publications showed clearly that the way the dewatering banana screen has been designed since its existence is not ideal. This led the Kwatani development team to engineer a new innovative banana screen design that still looks like a banana screen but outperforms traditional designs,” says Mayhew-Ridgers. Kwatani’s approach takes into consideration the type of screening panels used together with the process parameters and the screens’ mechanical parameters, of which there are at least seven; this ensures optimal performance. “This approach is different from others; the screen design remains the same while screening panels are replaced with other types of panels until a solution, and in many instances, a compromised solution, is found. Kwatani relies on its four decades of experience, in-house research and development team and test laboratory to come up with the best design for the application at hand,” adds Mayhew-Ridgers. A key case study is where Kwatani was approached by a South African diamond mine to improve the performance of its degrit process as the amount of water carryover that the operation was experiencing limited its existing screens’ throughput. Kwatani applied its new innovative approach to banana screen designs that required the adjustment of several of the mechanical parameters. “This was accomplished while being able to fit the newly-designed screen on the existing footprint without any changes required to the plant. Significantly, the Kwatani banana screen managed to double the mine’s throughput without increasing the size of the screen. This success speaks for itself,” says Mayhew-Ridgers. Optimum water recovery FLSmidth’s array of tailings management solutions is one way the OEM can ensure optimum water recovery and tailings disposal. Coupling that with its full flowsheet strength, FLSmidth is able to look upstream for opportunities on processing conditions that affect tailings requirements such as milling and flotation. The ability to optimise particle size distribution and metallurgical recovery with tailings in mind can further improve downstream impact to tailings.

A large Kwatani double deck banana screen used in the diamond mining industry.

While wet processing is a crucial part of mineral processing, water scarcity remains one of the burning environmental issues that operations have to contend with

FLSmidth’s array of tailings management solutions is one way the OEM can ensure optimum water recovery and tailings disposal

Kwatani’s believes that water management in wet screening applications is about retaining water in the water reticulation system

Dewatering of waste and concentrate streams as part of wet mineral processing is crucial to conserving water and to reducing mineral processing operational costs

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requirements and challenges, adds Douglas. Therefore, FLSmidth houses a full suite of testing, engineering services and technology dedicated to finding the right solution for its clients. Kwatani is one of the leading custom- designed vibrating screen original equipment manufacturers (OEM) in South Africa. Its view with regards to water management related to wet screening applications

is about retaining water in the water reticulation system. “This is achieved by reducing water overflow over the screen’s discharge end. Other factors are the quality of water, scaling of pipes that restrict waterflow and suspended solids in the water that leads to increased wear and leaking of water pipes, among others,” says Kenny Mayhew- Ridgers, COO of Kwatani.

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