Following delays, rock-breaking technology specialist Rock Eater is progressing with demonstrations of its low-energy rock-breaking controlled foam injection (CFI) Type One machine, with plans to design its second iteration this year, says Rock Eater strategic consultant Alastair Macfarlane.

Originally developed in the US for broader applications, investment and marketing firm IVV Investments Limited acquired the CFI intellectual property rights in 2023, subsequently enlisting Rock Eater to advance the technology through research, development and commercialisation processes as a continuous, non-explosive rock and concrete breaking system.

Rock Eater’s CFI solution works by drilling a 63-mm-diameter hole into a rock face, following which the CFI’s breaking unit – mounted on a single or twin boom rig – then indexes through 180º and inserts a probe to the bottom of the hole. Following this, a seal is inserted into the hole and high pressure foam is injected. The foam then applies pressure in the hole to initiate fractures which break the rock.

The rig then moves to the next hole with each breakout cycle taking up to four minutes, he explains.

He notes that CFI technology differs in how it breaks rock, explaining that explosives use high energy, while most continuous mining machines break rock through compression or cutting, which also requires significant energy.

“Our machine breaks rock in tension, which requires far less energy,” explains Macfarlane.

Innovative rock-cutting and non-explosive mining technologies are imperative, he says, as already deep mines extend deeper, owing to factors such as heat and seismicity increasing alongside reduced ore extraction ratios.



The CFI solution offers various benefits including faster advance rates, decreased unit costs, reduced re-entry times where possible, and a continuous and productive active face time, outlines Macfarlane.

The solution also reduces legacy rock breaking risks associated with the handling, storage and use of explosives, as well as reducing vibration, noise, dust, fumes and fly-rock that are present when explosive rock breaking methods are employed.

As the CFI technology uses no chemicals, it avoids groundwater contamination or nitrate runoff. The technology also requires less energy compared to conventional methods of rock breaking, such as drilling and using explosives.

Where the CFI Works
The CFI solution is suitable for various mining applications, including new service excavations, sloping alongside existing infrastructure and breaking through dykes in continuous miner sections in coal mines.

In underground mining applications, Macfarlane explains that the CFI solution is suitable for new developments, extensions and mature deep mines.

“New developments offer the greatest continuous and uninterrupted operation benefits while extension applications benefit from minimal disruptions to surrounding areas, infrastructure and communities,” he says.



Rock Eater envisages three machine types of CFI, which include a CFI Type One machine, CFI Type Two machine and CFI Type Three machine.

Type One is currently undergoing trials at two demonstration sites, whereby it is breaking rock and in an application that requires a separate unit to remove debris.

The Type Two machine, now under design, takes Type One’s capabilities further and will integrate cleaning functions to enable continuous rock removal, thereby improving efficiency.

The Type Three machine is still at a conceptual phase of development and will build on the Type Two machine with the incorporation of roof bolting technology.

“Our goal for 2026 is to deploy at least six Type One machines while finalising Type Two designs and fabrication,” says Macfarlane.