A visit to Pan Africa ResourcesEvander Gold Mines leaves a lasting impression, dedication to extracting maximum value from an old lady who still has a lot to offer.The Evander Gold Mines (EGM) acquisition has not only provided Pan African Resources (PAR) with an immediate production and revenue stream, but also a loyal, passionate and experienced team who are driven and committed to see EGM continue delivering on its steady production output and realise the longer-term opportunities that the mine still has to offer.

Adding EGM to the PAR portfolio may be largely attributable to former CEO Jan Nelson, but his exit has by no means affected the current performance, or the short- or long-term future potential of the mine. The COO and interim CEO Ron Holding, together with the on-site management team, is fully invested in realising value from the operation and has already initiated a number of internal growth projects that were on PAR’s radar even before the acquisition was finalised.

Maximising on EGM’s current potential

EGM may have doubled PAR’s annual gold ounce output from 100 000 ozpa to about 200 000 ozpa, but this is by no means all that the mine has to offer. It mines the Kimberley Reef and based on current resource and reserve figures, it still has a 15-year lifespan.

The Kinross process plant, situated just a stone’s throw from the single operating No 8 Shaft, has not been fully utilised for years, following the closure of numerous shafts, including 1, 2, 3, 5, 6, 9 and 10 Shafts, within the EGM mining areas over the decades. It may be old, but is still fully capable of delivering on its nameplate capacity of 240 000 tpm. According to the metallurgical manager, Thabang Hlalele, the plant is currently processing 40 000 tpm from 8 Shaft and another 20 000 tpm from old surface material.

Although EGM’s grade (about 7 g/t) is relatively stable, the general manager, Manny Da Silva, indicates that the mine is expected to see a drop in grades as the mining plan takes them towards the edges of their gold-rich payshoot, but this is only temporary. Activity continues with Evander’s deepening project, which Harmony commenced in 2010 to gain access to high-grade areas below 24 Level. Part of the project also required significant upgrades to the shaft’s infrastructure – particularly with regards to cooling and ventilation, which has been completed.

The most immediate priority, however, is to offset the drop in grades. “For a start, we are aiming to deliver about 6 000 tpm at about 2.5 g/t from vamping old gold bearing rock at No 7 Shaft, situated adjacent to the process plant. The shaft comprises twin headgears where one is currently used to transport underground 8 Shaft ore to surface. Vamping activity will take place at the unused men/material shaft. This is expected to start in July.

No 7 Shaft has the necessary infrastructure for mining in the old areas as well (pillar extraction etc.), and PAR is considering reopening some of these old mining sections. There is also the 2010 pay channel to the north-east of 7 Shaft where the company needs to evaluate the position of the reef, but this needs further exploration. “We only want quality ounces and will only pursue this project if it can meet our quality requirements,” says Holding.

Da Silva says that EGM is on the brink of completing the conversion of one of its self-grinding autogenous mills to a semi-autogenous mill, which uses steel balls to deliver a ‘finer’ grind. “This will allow us to extend the life of our 0.83 g/t surface sources for another two years,” he adds.

There is enough surface material to take the plant back up to its nameplate capacity and PAR is also evaluating the potential to process up to 200 000 tpm of slimes material. “We will target the higher grade dumps first. Our studies thus far indicate this particular project will average an expected recovered grade of about 0.17 g/t.”

The EGM process plant (commissioned in 1967)

  • 12 Silos; one in use with two feed belts (underground material and surface material)
  • 6 Mills;  two in operation
  • new cyanide plant
  • 5 heavy-duty thickeners ; two in use
  • hybrid carbon-in-leach and carbon-in-pulp circuits
  • two-column elution circuit – strip gold from carbon
  • smelter – gold sludge dispatched to Rand Refinery.
The exciting long-term prospects

While steady-state production remains the forefront priority, PAR is invested in unlocking EGM’s large and untapped potential, which includes three new underground mines and a massive tailings retreatment project.

Despite it age – prospecting started in the area in 1903 – EGM still has some of the largest untapped resources and reserves in South Africa. Underground measured, indicated and inferred resources across the priority identified areas total 109.5 Mt or 28.7 Moz at about 8.16 g/t. Reserves currently equate to 39 Mt or 0.2 Moz at 8.2 g/t, excluding surface material.

Prior to his exit, Nelson spoke enthusiastically of what he considered to be one of the operation’s most exciting prospects, “which lies not in the mine itself, but in its tailings”. There is approximately 203 Mt or 1.9 Moz of tailings material on-site, which PAR has started evaluating internally. “We are aiming to make a decision on how to maximise on the potential opportunities the tailings may offer within the next 12 months. We have already redefined its purpose by changing its name from Harmony’s Mini Libra to the Evander Tailings Reclamation project. We believe a plant capable of processing around 1 Mtpm at a grade of no more than 0.4 g/t is a definite possibility,” he said.

Rolspruit, an extension of No 8 Shaft situated to the north, is an attractive prospect. Based on historical records, the area has significant resources (25.5 Mt at 10.89 g/t for 8.9 Moz) and reserves (23 Mt at 8.29 g/t for 6.2 Moz) at high grades. This is high enough to warrant the construction of its own vertical shaft, although PAR wouldn’t fund the sinking of a shaft on Rolspruit alone.

Evander South and Poplar, which lie to the west and north-west of No 8 Shaft, would also require new shafts and process plants, and probably a joint venture funding partner. A completed drilling programme at Poplar indicates the 34.9 Mt resources lies at depths of between 500 and 1 300 m. It would average about 6 g/t for 7 Moz. A completed drilling programme at Evander South indicates the 29.8 Mt resource lies at depths of between 250 and 1 200 m at grades of about 6.1 Moz.

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