HomeBase MetalsDRA kills two birds with one plant at Nkomati

DRA kills two birds with one plant at Nkomati

The Phase 2B expansion project for the Nkomati nickel mine has been designed by DRA to enable the client, African Rainbow Minerals (ARM) and Norilsk Nickel Africa to process two minerals with one plant, in this case nickel and chrome.


Nkomati under construction.

Situated near Machadodorp, the plant for the project has been designed and is being built by DRA. The plant has been engineered to operate on the mine’s PCMZ ore instead of the MMZ ore of Phase 2A, currently at ramp up stage. While the PCMZ is a lower grade nickel ore it does contain a high chrome content and current market prices have made it attractive for the client to mine and process. The bulk of the ore will be mined from the client’s open pit operations with the remainder mined from a small underground facility.

The process plant’s milling circuit will incorporate a secondary mill while two additional flotation cell banks will also be added. DRA will also upgrade the tailings thickener as well as design and build a spiral plant to handle the chrome ore. The latter is a high end system which will share infrastructure with the existing MMZ plant. Also on the cards will be a new conveyor system and stockpile – 90 m long, 11 m wide and with two metre thick walls. The tailings line is a unique system as the dam is located 14 km away from the site and 200 metres lower. As a result, a choke system has been designed to slow down the tailings flow to the dam.


On reef boxcut pollution
control dam at Booysendal.

DRA is a multi-disciplinary engineering, construction and project management group. It leverages integrated resource solutions, from concept to production to enable it to tackle any size of project anywhere in the world. It currently maintains regional offices in Canada, India, Australia, the UK and China, managed from its head office in Sunninghill, Johannesburg.

Recent projects undertaken by the company include Brummersheim, Booysendal and Kroondal. In addition, DRA Technical Services (DRATS), the group’s winder specialist, has developed a unique system for Steyldrift based on decades old technology and DRA looks at matchmaking in the African mining industry.

The construction of DRA’s build-own-operate-transfer, or BOOT, project is underway at Brummersheim in Mpumalanga. The export coal washing plant will be fully financed by DRA on behalf of the client, Umthombo Resources which maintains an off-take agreement with a Turkish client. Once built, the R71 million plant will be operated by DRA sister company, Minopex, operating it on a rate per tonne basis. After two years the client will have the option to either take transfer of the plant or extend the operating contract further. The plant is designed to operate on a continuous six day per week basis with an annual throughput of 2.4 million tonnes.


Location of the Booysendal project.

Situated on the Eastern Limb of the Bushveld Complex in Mpumalanga, this project will see the development of a new UG2 platinum mine, infrastructure and concentrator plant. The R3.6 billion project, located in the Groot Dwarsrivier valley, is already underway and is expected to place the mine as a major competitor on the Eastern Limb.

DRA has commenced work on the Kroondal K6 mine shaft project, a pool and sharing agreement (PSA) between Aquarius and Anglo Platinum which will see the two miners pool their respective mineral rights and assets around the Kroondal and Marikana platinum mines applying the Kroondal model of wide reef underground mining using both mechanised and conventional drilling methodologies to sink a triple decline shaft system from the surface to the UG2 Reef intersection horizon 150 m below surface.


Construction of water storage
and supply infrastructure at

DRATS, the winder specialists of the DRA group, has designed a unique solution for the Steyldrift platinum mine in the Northwest Province. The company has designed a system incorporating multiple single-drum winder units to provide the slow rotation speed necessary to wind long rope lengths – typically 14 km of rope for the 2,000 m deep shaft. The design offers a high degree of flexibility to move the winders anywhere on the bank and operate them independently of each other while still maintaining a centralised control. The system uses considerably less space than conventional four-drum winders and eliminates the need for deflecting shields. The concept, while new to South Africa, is based on similar systems used in Europe about 20 years ago. The difference here is the systems size, considerably larger than those used in Europe with its 2.5 m diameter.

DRATS has also recently commissioned the biggest Koepe winder north of the Limpopo for Konkola – a six metre diameter system with 7.0 MW drive – as well as the only Blair multi-rope winder in Africa outside of South Africa – an 8.25 MW monster. These winders are the largest on Zambia’s copperbelt.


Making safe of existing temporary
access road to the on reef boxcut
at Booysendal.

DRA has entered into a new area not normally associated with its usual operations, this being finance and exploration and drilling management. With the current mining bonanza taking place throughout Africa, a number of new players are entering the market, many with the mineral rights but lacking the resources to exploit them. At the same time, foreign companies are looking for partners to develop mines by providing financing. DRA’s experience in platinum, chromium, diamond, copper, cobalt, nickel, lead, zinc, gold, manganese and ironore places it in a position to match mines to financiers, providing in-depth assessments covering aspects such as viability, lifespan, costs, profitability, short and long term stability, logistics and more.