Marikana

Overview

Commissioned in late 2002, Marikana is Aquarius’ second operating mine in South Africa.

Marikana is an underground mining operation. A concentrator plant processes the mined material. Concentrate produced is processed either by Amplats or by Impala Refining Services (IRS), depending on the source of the reserve originally mined.

Marikana has been managed in a 50:50 pooling and sharing agreement (P&SA2) with Anglo Platinum since 2005. The P&SA2 includes a dense media separation (DMS) plant, commissioned in November 2006.

Marikana mining and processing operation were suspended in June 2012 due to depressed metal prices and high production costs.

Location

Marikana Mine is eight kilometres away from the Kroondal mine, on the Bushveld Complex's western limb in the North West Province of South Africa. The mine is located 20 kilometers east of Rustenberg, which is situated some 112 km northwest of Johannesburg, at the foot of the Magaliesberg.

Rustenburg is the third oldest town of the former Transvaal Province and offers numerous places of interest. Its jacaranda tree-lined streets are the hub of a thriving agricultural and mining industry. The Bushveld Complex is one of the largest PGE deposits in the world.

Platinum was discovered in the Bushveld Complex in 1924, by Hans Merensky, however production on the Merensky reef and UG2 Chromite layer didn't begin until 1969, and 1980 respectfully. By the early 1990s Impala had become a 1 million platinum ounce producer.

Geology & Mineralization

Marikana is located 8 kilometres from the company's flagship operation, Kroondal, with both situated on the Western Limb of the Bushveld Complex. The Complex is an extremely large (66,000 square kilometres), 2 billion year-old, layered igneous intrusion occurring within the boundaries of South Africa. Contained within a well-layered ultramafic to mafic succession called the Rustenburg Layered Suite are two horizons which host economically exploitable quantities of PGMs, namely the Merensky Reef and the underlying UG2 Chromitite Layer.

The orebody, which measures approximately 1.5 kilometres by 3 kilometres, is a basin-like structure which dips down toward the centre from all sides at an angle of between 10 and 20 degrees to a maximum depth of about 200 metres. The surface topography is flat with a gentle slope to the north.

Marikana comprises both the Marikana and 4 Shaft orebodies, which are both part of the UG2 Reef. The Marikana open pit orebody, which measures approximately 1.5 kilometres by 3 kilometres, is a basin-like structure which dips down toward the centre from all sides at an angle of between 10 and 20 degrees to a maximum depth of about 200 metres. The surface topography is flat with a gentle slope to the north.

The 4 Shaft orebody is adjacent to the Kroondal Block at the Kroondal Mine and has a similar geology with the UG2 dipping to the north at approximately 9 degrees. This orebody comprises two mineralised seams – the Main and Leader seams – which are separated by a one-metre pyroxenite zone commonly known as the parting. 

As of December 2011, mineral reserves at Marikana were estimated at 14.46 Mt at 3.36 g/t for 1.56 Moz PGM. 

Mining & Operation

The open-cast operation was mined out in FY 2011.

On conclusion of the Firstplats transaction in August 2009, Aquarius acquired the Firstplats block, adjacent to Marikana's 4 shaft orebody, and the Salene block, which is adjacent to the Marikana orebody, each with correspondingly similar geologies.  These orebodies have both been incorporated in Marikana's P&SA2 with Anglo Platinum.  The M5 project, which involved the recommission of the western shaft on the Firstplats block, has begun.  This project will provide the infrastructure required to access large portions of Marikana's ore reserves.  It gives immediate access to the deeper reserves of the 4 shaft orebody. Although the geological features (potholes and faults) encountered during the year prevented the M5 project from achieving its targets, development by year-end was on-reef and yielding improved grades.

The additional underground resources contained in the Salene orebody can be accessed via 1 shaft, which is also being used to access the orebody previously accessed from 2 shafts, which was placed on care and maintenance last year.

Additional reserves, the Siphumelele 3 reserves, aree being accessed from the No.5 shaft and were being mined in 2011.

The adjacent Hoedspruit property if acquired could further extend the mine life.

In 2011, poor ground conditions and the closure of the No.1 shaft negatively affected production. No.2 shaft is also on care and maintenance. As a result of that the hangingwall support methodologies had been updated and redesigned. 

Shaft No.6 feasibility will begin during FY2013.

Marikana mining and processing operation were suspended in June 2012 due to depressed metal prices and high production costs.

Processing

The concentrator plant at Marikana has a monthly processing capacity of 220,000 tonnes.

Concentrate produced is processed either by Amplats or by Impala Refining Services (IRS), depending on the source of the reserve originally mined.

Marikana has a life-of-mine offtake agreement with Impala Refining Services, a subsidiary of Impala Platinum Holdings Limited

At the Impala Mineral Processes plant, the concentrator consists of 30 run-of-mine semi-autogeneous mills. The operation's key focus in recent years has been on improving concentrator recoveries which now stand at a record 84.5%. The smelter operates two immersed 37MW arc electric furnaces.

Environment & Community

Aquarius is committed to being a responsible employer and corporate citizen, encouraging sustainable initiatives in the areas and communities surrounding its operations. For example: local school children were provided with luminous bibs during the construction phase of Aquarius' Marikana Mine near Rustenburg since they had to pass through the site on their way to school.

In July 2010, a roof fall in the underground mine led to the death of five workers.

Rehabilitation of the mined out open pit was underway (2011).