The Reef Mole mining machine is a form of the AGA patented concept for use in underground mines with narrow reefs as found in South African gold and platinum mines.
The second version of the machine the RM950 is being tested in a mine near Rustenburg, SA. at this time.
It has been designed and developed by AG Associates (AGA) of Seattle, WA., USA. AGA is the original patent holder for South Africa and is the Intellectual Property Owner. Manufacturing and testing has been organized and managed by Rock Cutting Technological Service (RCTS), Witbank, SA.
The machine uses rolling insert cutters to excavate a rectangular opening. The upper photo shows the machine excavating a platinum ore reef. The opening size is 950 mm x 5000 mm. This machine has a power of 300 KW and excavates at a rate of 1 to 2 M/hour depending on conditions.
Since the rock fractures in small pieces it can be removed from the face by a vacuum system. It is then dumped into a shaft and collected at a lower level or deposited on a conveyor belt. The second photo shows the vacuum system power units.
Additional designs are available for different size openings as large as 2.5 M x 5 M for access and development drives.
Licensing partnerships can be developed for other countries.
If you would like more information contact AGA at these email addresses.
The RM 950 is being tested in a mine near Rustenburg, SA.
See below for example of Reef Mole setup and excavation patterns.
RM 800 Cutter Head and Platinum Reef
Vacuum Muck Removal System
RM 950 in final assembly
Some examples of narrow reef stope mining.
UG 2 Platinum reef in South Africa
Layers of ore bearing the heavy metals are present under the plains of the High Veldt of South Africa. This picture shows a platinum ore layer about 200 meters below the surface near Rustenberg, South Africa.
The ore is removed by creating rectangular openings that are approximately 9 meters wide. A checker-board pattern of 5 meter square pillars is left in place to support the weight of the earth above the ore layer.
This is a cut-away model that illustrates the pattern of pillars in the excavated area. The rock is fractured by drilling and blasting and removed using large Load-Haul-Dump vehicles. The openings created are as high as 2 meters to provide clearance for the drilling and ore removal vehicles. The ore thickness is 300 to 400 mm. This size differential leads to a high percentage of waste rock also having to be processed.
The material removed tends to be in relatively large pieces and removal from the mine occurs for a short scheduled period every day.
RM machines remove the ore layer along with another 600 mm of material. Their 300 kw power enables them to excavate the same area in a month as current excavation methods. The broken material removed is of a small size and vacuumed from the face. It doesn't need primary crushing and production is continuous throughout the day.
A month's production of ore is produced by only processing one half of the normal amount of material because of the reduced dilution ratio. Area recovery percentages are similar.