The mining industry has long grappled with the challenge of efficient mass transfer within metallurgical plants – a crucial factor that directly impacts both reagent consumption and mineral recovery. In response to this legacy problem, ore processing technology company GoldOre has developed a “disruptive innovation that is redefining standards in mineral processing” – the globally patented MACH Reactor, highlights GoldOre director Adrian Singh.
Australia is renowned for its sulphidic orebodies which are more difficult to treat than, for example, the free milling Witwatersrand ores found in South Africa, he explains.
The MACH Reactor is custom made for these sulphidic and semi-refractory ore types found in Australia as well as north-west Africa and is able to efficiently deal with the cyanicides that increase reagent consumption and reduce recoveries in these ores, says Singh.
“The end result is reagent savings of up to 30% and recovery improvements of between 2% and 8%, which goes straight to the bottom line to enhance profitability and financial viability of marginal operations,” he elaborates.
The MACH Reactor is a hydrodynamic cavitation device that generates pico- and nanobubbles in its supersonic venturis with “unmatched” turbulent kinetic energy dissipation rates aided by shockwave generation, explains Singh.
The picobubbles enhance the gas use efficiency in gold plants and the extreme mixing improves diffusion to accelerate leach kinetics and overall recovery.
Conventional flotation plants typically struggle to recover fine mineral below 10 μm in size owing to poor particle bubble contact. The MACH solves this problem by growing bubbles directly on the surface of valuable fine particles, aggregating them through intense mixing and then presenting a pseudo larger and easier floating particle to the conventional flotation system.
The result is higher concentrate grades and recoveries at lower mass pulls, which is the ultimate goal of any flotation system, he says.
The tried and tested MACH Reactor has a reactor life beyond ten years, while he says ease of operation is guaranteed with zero maintenance required throughout the reactor life.
“High wear and blockages have plagued older shear reactor technologies for ages, and so to have a reactor that is based on cavitation which is ‘streets ahead’ of shear and still requires zero maintenance with negligible wear,” he says, is a “feat to behold”.
Where to Deploy
The MACH Reactor also finds application at the tail end of a processing plant in cyanide destruction and arsenic remediation applications to both improve the cost effectiveness of these processes as well as reduce the environmental impact with “superior process performance”, states Singh.
A new advancement to the reactor’s design is the incorporation of multiple ringmains between the venturis which serve as reagent dosage points.
This configuration, he points out, is a strategic enhancement aimed at increasing both gas and liquid reagent use efficiency.
The design ensures that reagents are introduced precisely at the points of suction between the venturis, thereby promoting optimal mixing with slurry.
“This novel technique addresses one of the most persistent inefficiencies in metallurgical processing – poor contact between reagents and the mineral-laden slurry,” says Singh.
The ringmains are constructed in various diameters, customised to specific process requirements and fabricated from chemically-resistant stainless steel to ensure long operational life.
Each ringmain features unique GoldOre-designed, one-way valves, which is an additional critical safety feature that prevents slurry ingress into the reagent lines, safeguarding the integrity of the system even in the unlikely event of a backflow, even though the reagent addition points are under suction conditions, he explains.
“The MACH Reactor is more than just another piece of metallurgical equipment; it is a leap forward in processing technology. It combines intelligent design with practical application, delivering benefits that extend beyond traditional metrics,” he states.
By solving the issue of inefficient mass transfer, Singh says GoldOre has not only improved the economics of mineral processing but has also contributed to more sustainable mining practices through reduced reagent consumption and improved resource recovery.
“As the industry continues to evolve and confront new challenges, the MACH Reactor exemplifies the type of innovation that will lead the way. It is a powerful reminder that sometimes, solving age-old problems requires not just new ideas, but the courage to implement them in transformative ways,” he concludes. 
