Modder East


Gold One’s operation is the Modder East Mine, the first new mine to be built in South Africa’s gold-rich East Rand region in over 30 years. With a currently defined ore reserve of 1.53 million ounces at 4.0 grams per ton and a 13 year life of mine, Modder East’s target reefs are located no deeper than 500 meters below surface. The mine’s shallow resources allow for trackless mine infrastructure where the underground ore body is accessed via a decline.

Dedicated trucks transport rock out of the mine while a vertical shaft provides quick face access for personnel.
Modder East’s first 240 ounce gold pour took place in July 2009.The mine’s first ton of gold was poured in May 2010, only 10 months after its commissioning.

At Modder East Operation all the main development is a trackless mechanized system. This facilitated the use of emulsion and the shock tube system for blasting operations whilst the narrow reef stoping operations used the cartridge explosives, and shock tube initiating system.

In the latter part of 2012 Modder East made a decision to change all blasting operations over to emulsion system for the following reasons:

  • Explosives costs could be reduced by 25% per m².
  • An additional 20% of tramming time for production could be achieved with the elimination of explosive transport carriers and charge up units from the decline system.
  • Megapump emulsion carries a UN class 5.1 classification; it is not an explosive until sensitized at the blast face. This allows for improved safety and simplified logistic systems throughout the operation.
  • Legal compliances with the Mine Health and Safety Act and Explosives Act and regulations would be drastically reduced with the regards to the delivery, transporting receiving and storage of explosives.
  • Eliminates the risk of theft of cartridge explosives for illegal miners and ATM bombings thereby minimizing the DMR to issue a Section 54 stopping production or with drawing user’s license for explosives.

In order to assess the benefits of emulsion in narrow reef stoping operations a three month trail was undertaken by Sasol and BME to determine the most effective emulsion system.

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