Coarse flotation – recent news highlights developments and value opportunities for miners

Coarse flotation 
<br />– Image sourced from Eriez website:
Coarse flotation
– Image sourced from Eriez website:

Coarse flotation technologies are now emerging as real options for miners. They will have a significant impact on energy use and grinding time, thereby reducing costs and power consumption, and improving productivity.

In this post, CEEC shares some highlights, including a recent useful summary article from Mining Magazine and recent announcements from Australian Mining and Mining Monthly showcasing installations and applications.

Our industry is at an exciting stage of coarse flotation development, with high expectations and potential being taken up by miners. Some of CEEC’s valued sponsors are active with advances and installations, including Eriez and FLSmidth, highlighting the opportunities and challenges.

Earlier this year, CEEC’s CEO Alison Keogh discussed developments with Eriez and FLSmidth staff. In a previous news post announcing Eriez's sponsorship, she said there was potential for miners to add significant value through flotation of coarser material.

“Grinding less before flotation and simultaneously improving coarse particle recovery has the potential to help revolutionise the process. This can drive significant energy efficiency and productivity improvements in comminution and other mining and mineral processing steps,” she said.

“When successfully commercialised at full scale, coarse flotation will dramatically reduce costs by lowering use of energy, water and other resources per unit.”

Eriez Managing Director Australia, Jaisen Kohmuench, believes Eriez Flotation Division’s HydroFloat™ separator for coarse particle mineral concentration will dramatically reduce the amount of grinding energy, recovering particles with as little as 5% surface exposure.

“With grinding consuming up to 3% of the world’s total electrical energy consumption, coarse flotation could save the industry significant costs and greatly reduce its energy use and carbon footprint,” he said.

In the Mining Magazine article, Outotec Technology Director – Flotation, Ben Murphy, described coarse flotation as a balancing act.

“Getting particles at this coarse end of the spectrum to float is a balancing act getting the right particle properties, chemical conditions and the hydrodynamic conditions created by the flotation equipment,” he said.

He noted that as advances were delivered to extend this capability, “efficiencies for particles even in the 200-400µm range … would likely have a significant impact on how plants are designed and operated.”

CEEC sponsor FLSmidth’s research and development is focusing on not only coarse flotation but how it can be complemented with other steps and opportunties across mineral processing, including:

  • Alternative flotation technologies that reduce residence time and foot print through reduced fluid dispersion or the separation of collision and attachment sub-processes
  • Deployment of ore pre-concentration technology to separate waste rock prior to processing
  • Separation techniques which minimise or eliminate water consumption
  • Grinding technologies that may increase throughput at minimised power consumption yet allowing for acceptable maximum mineral recovery
  • Predictive wear and maintenance technologies
  • New froth removal techniques
  • Digitalisation of flotation circuits to maximise utilisation and minimise OPEX.

See the full Mining Magazine article here.

Eriez is active in installations, as demonstrated through the recent announcement that it will supply Newcrest Mining’s Cadia Valley gold operations in New South Wales with two HydroFloat™ separators and four CrossFlow™ classifiers to recover gold and copper from a concentrator tailings stream.

An Australian Mining article reporting on this announcement in September found that HydroFloat™ separators for coarse particle mineral concentration were able to deliver the capacity of a density separator, while maintaining the selectivity of a flotation device.

According to the article, the CrossFlow™ separator is "an efficient hydraulic classifier for the separation of material based on particle size, shape and/or density" that can be applied to coal, iron ore, industrial minerals, base metals and sulphides. Eriez's other technology, the HydroFloat™ system, uses “a novel aeration system to disperse fine bubbles into a fluidised-bed environment”.

CEEC welcomes news from our followers highlighting installations, case studies and advances that can add value and options at sites.

More information from the Australian Mining article here

More information from the Mining Monthly article here.