Evander Mines exploits the Kimberley Reef in the Evander basin, the eastern-most extremity of the Witwatersrand Supergroup. The Kimberley Reef is mined throughout the major gold mining districts within the Witwatersrand Supergroup, including the East Rand, Central Rand, West Rand, Far West Rand and Free State goldfields. Deposition models for gold within the conglomeratic horizons follows a palaeo-placer-type sedimentological deposition along with winnowing, erosion and concentration of gold-bearing footwall lithologies. Various studies have highlighted the importance of hydrothermal activity for deposition, remobilisation and enrichment within certain packages of the Witwatersrand Supergroup.

The Kimberley Reef is an oligomictic, pebbly conglomerate and comprises a composite sequence of channel sediments that define longitudinal gravel bars and sand bars with pebbly veneers. The reef in the area strikes in an east-west direction and dips to the north at about 10 degrees. The area is also divided by two major normal faults, striking in an east-north-east to west-south-west direction. The reef thickness varies from a waste on contact up to a 50cm well-developed oligomictic conglomerate. Average reef thickness is 35cm within the 8 Shaft vicinity. High gold values in the Kimberley Reef are mostly located at the base of the unit and are associated with the presence of carbon and some visible gold on the footwall contact.

The ore being treated at Elikhulu originated from previously mined and metallurgically treated Kimberley Reef from the Winkelhaak, Leslie/Bracken and Kinross Mines as part of Evander Mines’ operations.

Evander Mines (Leslie, Bracken and Kinross Mines) exploits the Kimberley Reef, where mining methods employed include underground conventional breast-type scraper mining and railbound equipment with some trackless mechanised development. More recently, the Elikhulu surface tailings retreatment operation was commissioned by the Group in August 2018.

Evander Mines
The current revenue streams for Evander Mines are primarily generated from Evander Mines’ 8 Shaft (8 Shaft) pillar mining and Elikhulu.

In 202 Life-of-mine 14 years (2021: 5 years) due to the addition of 25 and 26 Level mining areas.

Evander Mines currently mines the 8 Shaft pillar and re-processes surface tailings facilities via Elikhulu.

8 Shaft is An underground complex consisting of vertical and decline shaft systems. Gold-bearing reef is mined from 8 Shaft pillar, approximately 1.6km below surface and nfrom 24 Level, some 2.4km below surface. Ore is transported through the decline shaft systems to 15 Level. From there, the ore is transported across to Evander Mines’ 7 Shaft (7 Shaft), where it is hoisted and conveyed to the Kinross metallurgical plant.

The 8 Shaft boundary covers an area of 44km2 and is located between the Rolspruit project to the north-west and 7 Shaft to the south-east. The 8 Shaft pillar mining, however, only covers approximately 0.3km2 of the total 8 Shaft area. During the 2022, mining occurred in the 2 Decline area on the western side at a depth of 2,300m to 2,500m below surface as well as at the 8 Shaft pillar at a depth of 1,600m below surface.

All underground mining development and infrastructure placement for the mining of 24 Level progressed according to plan. Furthermore, environmental engineering contractor Bluhm Burton Engineering Projects progressed with the construction of the underground refrigeration plant within the mined excavation area created on 24 Level during the reporting period. Commissioning of phase 1 of this refrigeration plant is expected during the first quarter of the 2023 financial year while that of phase 2 is expected in quarter four. Phase 1 of the project will enable mining of both the 24 Level F line stopes and mining of the 24 Level B, C and D raise lines. Phase 2 will allow for additional mining crews to be placed on 24 Level as well as for subsequent mining on 25 Level.

The Group has internally evaluated the potential for continued mining on 25 and 26 Levels from 24 Level at 8 Shaft, where the 2 Decline extends from the bottom of 18 Level. Development leading from the existing 24 Level footwall infrastructure allows access to both 25 and 26 Levels, with an on-reef decline layout. The mining of 25 and 26 Levels demonstrates a compelling business case and will extend 8 Shaft’s production profile, post cessation of operations at of the 8 Shaft pillar and the 24 Level complex, for an additional eight years, with annual production of approximately 65Koz.

The project development plan is as follows. The existing 24 Level footwall infrastructure intersects the Kimberley Reef horizon on 25 Level. A twin-barrel on-reef decline system will then access the higher-grade ore extending deeper to the north-west of the current 24 Level mining area. Due to the shallower dip in the area, sublevels will be introduced to limit mining back-lengths to approximately 150m.

The mining method employed at 25 and 26 Levels will be a hybrid of conventional breast mining and mechanised trackless on-reef development. Stope faces will be drilled utilising handheld pneumatic-driven air lcg-assisted rock drills. Blasted ore will be cleaned by means of a series of scraper winches from the face into strike and centre gullies. Ore will be collected in ore loading bays at the bottom of the raise and then loaded with diesel-driven load haul drivers and tipped onto strike conveyors running along the sublevel strike drives. The strike conveyors will deposit the ore onto the decline dip conveyor, which will tip the ore into bins. Ore will then be drawn on 24 Level and transferred by diesel locomotives to the vent shaft where the ore will be hoisted to 17 Level and tipped down to 18 Level.

As a result of the on-reef development layout, limited waste from 25 and 26 Levels will be blended with the ore stream and processed at the Kinross metallurgical plant.

The ventilation and refrigeration studies for mining the 2 Decline on the 25 and 26 Levels were completed by an independent consulting company.

Elikhulu
Hydraulic mining of the Kinross tailings dam is utilised to pump material at a rate of 1.2Mt per month to Elikhulu.

- subscription is required.

The Evander Gold Plant (also referred to as the Kinross Gold Plant) is situated in the town of Evander, in Mpumalanga Province, South Africa, approximately 134 km east of Johannesburg. The Evander Gold Plant treats ore from Evander No. 8 Shaft.

The ore is transported across to Evander Mines’ 7 Shaft (7 Shaft), where it is hoisted and conveyed to the Kinross metallurgical plant. The plant consists of a milling, gravity gold separation and CIP circuit with a carbon regeneration section, elution (and electro-winning) circuit and smelt house. The Kinross plant capacity is currently 55ktpm, but can be upgraded to the original design capacity of approximately 240ktpm with the refurbishment of defunct mills.

A portion of the cyclone underflow is directed to Knelson centrifugal concentrators for the recovery of free gold. There is one Knelson concentrator for every two milling units.

The cyclone overflow is directed, via linear screens, to five thickeners (of w ........