The customers of Weir Minerals Africa are enjoying the benefit of vastly improved efficiencies from the Warman® AHF™ froth pump. This is a result of the extensive test work initiated about 18 months ago. Coupled with a fundamental change in the design layout associated with implementing AHF pumps such as such as feed tanks, orientation and footprint, these pump design improvements have resulted in enhanced, revitalised and corrected concentration froth handling, effectively positioning Weir Minerals as the market leader in this technology.

The heavy duty Warman® AHF™ froth pump: whilst based on and interchangeable with, the well-known Warman® AH and L pumps, has been modified to handle difficult froth slurry. Key to the unique Warman® AHF™ froth pump design is a significantly larger-than-normal inlet diameter with a unique impeller inducer blade which is able to handle heavy froth and higher viscosity dense slurries with ease. This larger inlet, with correspondingly larger inlet volume allows the handling of significantly greater expanded air volume without air binding, with less surging, therefore making it possible to install a smaller pump.

Weir Minerals Africa has conducted local test work based on findings drawn from research conducted in North America and Europe over the past seven years. Rui Gomes, product manager: slurry pumps at Weir Minerals Africa, says this research allowed his team to understand the variability that takes place at different plants and how the AHF™ pump can be adjusted to respond to these irregularities.

“Being able to tap into the latest proven methods and apply them to local operations is one of the benefits of being part of a large multinational organisation,” adds Gomes. “The mining industry is plagued by froth and high viscosity problems and, in the process of recovering minerals from the ore, the slurry is often floated by utilising strong flotation agents. The hydrophobic bubbles carry the concentrate to be recovered and further processed. This can create complications within standard slurry pumps. The typical consequence is that conventional sumps are prone to overflowing, leading to spillage and loss of valuable concentrate, as well as posing a risk to the environment. This in turn often results in the selection of overly large and inefficient pumps.

“The Warman® AHF™ froth pump is small and efficient. The inducer impeller and oversized inlet are very effective in assuring that froth or viscous slurries enter the impeller, allowing the pump to transport it to the next destination.  Lower power costs, reliable operation, greatly reduced surging and feed tank overflow make this pump extremely user friendly.

“When it comes to concentration froth, there’s no ‘copy and paste’ solution, as was the theory in the past, because individual applications vary over a broad spectrum,” Gomes concludes. “We therefore continue to collaborate with customers to conduct on-going test work that guides the application of this pump technology to suit their unique processes.”.