Obuasi mine could last 50 yrs

The total gold ore reserves and resources at AngloGold Ashanti’s Obuasi Mine is estimated at about 27 million ounces, which could all be mined within the next 50 years at the current mining rate.

Executives of AngloGold Ashanti- operators of the mine- said on Tuesday that the Obuasi mine currently boasts of seven million ounces of gold ore in reserves while about 20 million are held in resource- a term used to describe minerals that are potentially economically feasible. Reserves on the other hand are minerals that are economically extractable at present.

The Executive Vice President Sustainability of AngloGold Ashanti, David Noko explained that the lifespan of the mine could be extended beyond the next half a century if mining activities at the mine is reduced to its optimum.

Asked about how much gold is left to be mined at the biggest underground mine in Ghana, Mr. Noko said: “If we mine the existing reserves, which are just over seven million ounces, at the current mining rate, we are looking at about 20 years.

“After good development of the infrastructure that will give access to the resource- there is still work to do on the resource because we don’t know much about it unlike the reserves which we know its quality and whether its minable- if we are successful in doing all that, and I have said that we have about 20 million ounces in resource, that basically increases the mine to potentially 50 years of life at current mining rate.

“And the current mining rate is relatively higher. Optimally we should mine at a lower rate than we are mining now, then the mine has longer life than the 50 years that we are talking about.”

Over the past two years, operators of the mine- Anglogold Ashanti- has embarked on a an estimated US$220 retrenchment exercise to downsize its workforce as it limits operations of the 117-year-old mine.

Currently AngloGold Ashanti has started a process to modernise its Obuasi mine and reverse a long trend of declining production and rising costs.

This project is focused on the development of a new decline roadway system from surface to by-pass aged infrastructure and more efficiently access the upper ore zones, some of which are not currently in the mine plan and the deeper, higher-grade areas of the ore body to allow for additional ore extraction to meet the 2016 production targets. The project is expected to complete by 2016.

So far, further fundamental changes at Obuasi Mine aimed at systemically addressing legacies, infrastructure, development constraints and cash outflows are now being implemented while surface production, exploration drilling and decline development remain ongoing.

This work includes initiatives to reduce footprints of the operation and consolidate infrastructure, and lower operating costs by introducing a mechanised mining approach in the future -- together with refurbishment and automation of the processing plant.

The Obuasi Deeps Decline project, which started in July last year, reached an important milestone this month -- completing the decline from the surface to below the 17 Level, which is more than a third of the total decline project.