HomeExplorationObuasi neighbour kicks into full gear

Obuasi neighbour kicks into full gear

AIM-listed GoldStone Resources is underway with the sinking a new shaft to access the historic high-grade Akrokeri underground gold mine at its Akrokeri-Homase gold project.

Ghana – The Akrokeri underground gold mine is one of two previously producing operations at the Akrokeri-Homase gold project (AKHM) and will enable the company to complete a geological assessment of the mine.

The Akrokeri mine is located approximately 6 km along strike from one of the world’s major gold mines, AngloGold Ashanti’s Obuasi mine, which has a total historical and current resource in excess of 70 Moz of gold.

Emma Priestley, CEO of GoldStone, comments:

“This update is a culmination of the previous six month’s work, that for the first time includes the collation and review of information from all historic exploration, drilling and mining activities across the project, which we believe reinforces AKHM’s prospectivity and upside potential.

“We are extremely excited by the opportunities at AKHM, including several new targets identified during the review, being the Akrokeri Mine, the potential for further pits along the Homase Trend that includes the Homase pit, which was mined by AngloGold in 2002/3 at a recovered grade of 2.5 g/t gold, and additional parallel zones.

“With Ghana’s Parliament recently ratifying the regulatory and fiscal agreements for the redevelopment of our neighbour, the Obuasi gold mine, and the issuing of their environmental permit, the attitude in Ghana towards mining is increasingly positive, reinforcing the backdrop to our strategy of rapidly advancing the project and achieving production within two years.

Accessing the Akrokeri mine

The main focus of work at the Akrokeri mine is the sinking of the Norton shaft, which is being developed adjacent to the historic North Shaft to access the:

  • historic ore body area; and
  • old underground mine workings.

Access to the old mine workings will, depending on the ground conditions, also enable GoldStone to carry out geological mapping and to investigate potential ore that was not exploited by the historic miners.

The Akrokeri mine was closed in 1909 having produced 75 000 oz of gold at a final recovered average grade of 0.73 oz/t, equivalent to approximately 24 g/t.

It is often the case that in historic underground mining, considerable amounts of ore were often left behind, both in-situ and also from spillage that was never cleaned up.

The Akrokeri mine is particularly interesting in this regard, due to the fact that the mine was abruptly closed following an ingress of water meaning that a mine clean-up was, in all likelihood, never executed.

On that basis and assuming the gold recovery from previous workings was not 100%, the board believe that the mined head grade at the mine could have been greater than 24 g/t gold.

Goldstone is currently sinking the Norton shaft, measuring 3 m x 3 m, to approximately 30 m depth below surface.

The Norton shaft is being sunk approximately 40 m to the east of the existing North shaft that is now derelict.  Work at the old North shaft is currently under way to ascertain if this shaft can be re-opened for use by Goldstone.

Depending on the state of the shaft, it may be utilised as a second point of egress, for ventilation purposes and also to gain access to the old underground mine workings.

As at 6 July 2018, the Norton shaft had been sunk to 20 m depth below surface and 19 m fully timbered and partitioned.

Due to the ongoing deepening of the Norton Shaft, an electric driven winch is being installed to assist with the extraction of the materials.

Scoping study for bulk sample/test work

Since the confirmation of the >8 km Homase Trend, which runs from the Akrokeri mine to north of the Homase pit and includes the current mineral resource of 602 000 oz JORC classification, GoldStone has initiated a scoping study to strategically locate material to produce a sample for a bulk test-work programme.

This is an important step in the company’s aim of achieving production within two years as it will assist with determining the optimum recovery process for AKHM, combining both gold recovery and cost effectiveness.

It is the company’s intention, once the Akrokeri mine has been accessed, to also accumulate a bulk sample from the underground deposit for the test-work programme.  Once the deposit is accessed the size of the bulk sample will be determined.