• The barrier to lower cost and safer mining is the blasting cycle with its in built inefficiencies.
• This consists of the following separate activities:

–Drilling blast holes.

–Vacate the mine before blasting, blast and then wait for the fume and  dust to dissipate.

–Travel to the working place and make safe.

–Clean the broken rock from the new face.

–Support the newly exposed rock.

• Face working time is typically less than 8 hours per day for 11 days per fortnight or about 25% of the total available time

It Hasn’t with Tunnel Development

• Drilling technology has not increased face advance rates:

Over 50 years the drilling rate has increased by five, while the tunnel  development rate has reduced by 66%.

Reasons for lower development rates are:

• In the 60s there were multiple operations at the face & high incentive bonuses.
• Legal restrictions on multi-blast operations.
• Now the emphasis is on safety and separated operations.

• The technology used for continuous mining must deliver.

Increased Safety – Do less damage to the surrounding rock, resulting in less  over break, less support required and a safer operation. Also to reduce exposure to explosives, fumes , dust and noise.

Higher Productivity – Increased utilisation of assets, the mine and the  equipment, by operating 24/7. Increasing equipment and plant productivity.

• Can work less face for same production. Thus better management control. Equipment works more hours and produces more per month, better equipment capital utilisation.
• The productivity of current mining is impacted by constraints of available time and available “pit room.” Removing these constraints through simple continuous mining must increase output.
• Less ventilation & other services. Fewer items of equipment working for longer rather than a larger number of pieces of equipment operating for a shorter peak period.
• Higher rates of development in tunnels to optimise mine layouts and to reduce time to production.

Environmentally Friendly – generating no toxic fume or dust and operate 24/7.

Proven Technology – New technology development takes many years, the solution needs to work with currently available technology.

• The technology used for pick cutting has progressively improved with Roadheaders now operating in rock up to 100 MPa but more like 50 MPa
• Tunnel Boring Machines (TBMs) and Raise Borers operate in very hard rock. (600 MPa)
• Full face cutting is used by TBMs and Raise Borers and the forces required are directly related to the compressive strength of the rock, whereas, cutter life is directly related to the abrasivity of the rock.

–The high forces require massive machines and high installed power (2 MW for a 4m  diameter TBM in quartzite).

– Where multiple tunnels or excavations are required, the capital cost of these machines is unjustifiable

–The high abrasivity results in low tool life. (60% of the operating cost)

An unattractive double whammy of high capital cost and high  operating costs – only viable in specialised activities.

• There are a number of problems with cutting hard rock:

–Roller or disc cutters are the only ones suitable for hard rock cutting and  deliver a circular cross section.

–Roller cutters require large forces to penetrate the rock in compression,  hence large and capital expensive machines requiring high power.

–High operating costs due to high power and forces.

• A number of OEMs are currently testing hard rock cutting machines for development & stoping applications.
• Three OEMs are using undercutting as this partially exploits the much lower tensile strength of the rock and energy consumption is about 25% to 40% of full face cutting.
• Machines still have high capital costs.
• Hard abrasive rock means low cutter life and hence operating cost is still a challenge.
• There have been intensive efforts to develop harder and more abrasive resistant cutters, especially with diamond composites, over the past 20 years – but very little to show in  demonstrated real performance in practical rockcutting.

• Foam has variable viscosity which CFI exploits. For fracturing it utilizes a very high viscosity compared to gas.

–Thus reducing process speed and therefore fracture pressures, air  blast and fly rock.

• Foam can store energy.

–The gas phase provides continuing pressure during fracture expansion  and rock breakage.

• Improved Borehole Sealing is needed to contain the high foam pressure.

–A proprietary crushed sand seal has been developed and proven to be  a uniquely effective and inexpensive hole seal.

No toxic chemicals – no chemical reactions.

All ingredients except one are used in commercial food products

• The exciting thing about CFI is that it can find application wherever small diameter and short blast holes have been used in the mining industry. Typically  the gold, platinum and chrome mining operations in  Southern Africa.
• CFI can replace explosives in these applications and the mining industry can have a genuine hard rock, non- explosive rock breaking tool for tunnelling and stoping.
• Larger tunnels may employ multiple CFI rock breakers in each heading.
• In mechanised hard rock mining of narrow tabular ore bodies typical of gold, platinum and chrome in Southern Africa and copper in Poland all the rock is broken using short hole drilling  and blasting.
• Narrow reef stoping at steeper dips would require different machines employing CFI.
• Narrow vein mining practiced all over the world and for a variety of minerals would also require a different mining machine.
• Breaking through dykes in mechanised coal mining operations.
• Secondary breaking in cave and long hole open stoping operations.
• Many civil rock breaking activities take place in built up and congested environments. Noise, vibration  and fly rock are all problems that CFI could solve.
• A lot of commonality exists for the multiple applications, especially with the CFI boom, and the carrier.