Two billion years ago, a series of violent volcanic eruptions occurred in what is now Phalaborwa, in the Limpopo province of South Africa. These eruptions were spread over millions of years, slowly building up a rich and unique body of minerals – copper, phosphates, magnetite, uranium, zirconium, nickel, gold, silver, platinum, and palladium, and in similar veins nearby, vermiculite and phosphate. The hill this treasure trove is buried under is known as Loolekop, and the treasure itself as the Palabora Igneous Complex.
Modern mining efforts were not the first to reach Loolekop. Artifacts suggest that surprisingly pure copper has been mined and smelted here as early as the 8th century. However, it was at the beginning of the current century that modern miners began to turn their eye to this Complex, after geologists discovered he phosphate bearing mineral, apatite, in the area.
The Palabora Mining Company Ltd began operations in 1956. Their subsidiary, Palabora Copper, mine, smelt and refine copper from this unique formation, with all of their facilities housed in Phalaborwa. The company is South Africa’s sole producer of refined copper, with an impressive output of between 45,000 to 60,000 tons a year. On top of this dominance of the refined copper market, the mine also processes and exports a wide range of by-products from the mineral-rich soil, including Magnetite, Vermiculite Sulphuric acid, anode slimes and nickel sulphate, as well as small quantities of gold, silver and platinum. During the 1960s, 1970s and 1980s, the company’s open-pit copper mine and processing plants produced over 2.7 million tons of copper.
Part of what makes the Palabora Igneous Complex so unique is that, due to its volcanic history, it is the only known place where copper occurs in carbonites, rather than the usual sulfides. As South Africa’s only refined copper supplier, they sell most of their output to the local market, only exporting the excess – along with the various additional minerals they are able to process from the valuable ‘waste’. Not content to rest there, they also own a nearby vermiculite deposit, which is mined and processed for sale worldwide.
Palabora’s operation employees around 2,200 people. The large block cave mine in connected with the company’s smelter and refinery complex, and works closely with the company’s vermiculite operation. However, their attention goes beyond these operations, with the company deeply involved with the surrounding area: the mines are located close to Kruger National Park, protected land and a popular eco-tourism attraction for South Africa. With this proximity comes a responsibility to ensure that their operations do not impact negatively on the park. In response to this, and as a part of their ongoing commitment to sustainability, Palabora have committed some of their staff and resources to coordinating several onsite wildlife management and cultural heritage programmes, designed to protect and promote the nature and cultural history of the area. They also work closely with many of the communities in the area to strive to support them and boost economic development.
This community responsibility is all a part of Palabora’s high standards for itself. As the company states, “Palabora strives to grow sustainably and profitably while delivering excellent value to all our stakeholders. We achieve this through the efforts of our talented people, safe operational practices, best-in-class technology and a commitment to excellence in all we do.”
Palabora describes its copper mine, an underground block-cave, as a “benchmark for integrated design. No other block-cave mine has been put into as competent an ore-body. The block height of the cave reaches a record 450 meters in the centre, increasing up to 700 meters on the periphery, rendering Palabora a world-class mine.”
Geographically, the mine’s actual production footprint is small, measuring in at only 650 by 200 meters wide, with 20 production cross-cuts and 320 draw-points. As the company explains, “With the coarse fragmentation of the ore body, a high degree of secondary breaking activities is required to treat hang-ups and oversize; and to keep ore flowing through the draw-points for the loaders to haul.” The mine’s construction was completed in late 2004, and by May 2005, operations were impressively already producing 30,000 tons.
Ore from the mine is carried to be processed both by haulage vehicles and then, once it has been crushed to a manageable size, an efficient conveyor system. “Our fleet of Load-Haul-Dump vehicles tip 3,000 buckets of ore per day into four jaw crushers on the northern side of the footprint. Ore is reduced to less than 220mm and fed onto a high-capacity conveyor system up to the shaft complex from where it is hoisted to the surface.”
During processing, a dried copper concentrate is blended with fine quartz flux and process materials, which are recycled from upstream for sustainability. It is then put through a reverberatory furnace burning at 1,400°Cm which separates the melted material into two layers – a layer of copper and a layer of unwanted slag. The process then continues to blow hot air through the material to oxidise any sulphur or iron in the mix, allowing it to be removed, and ultimately resulting in blister copper that is 98% pure. Again in the name of sustainability and to avoid waste, excess heat from this process is then used to melt the facility’s internal recycling and copper scraps.
Meanwhile, mining at Palabora’s adjacent vermiculite resource is carried out by ‘blasting’ the ore in the 50-meter-deep pit. The ore is then loaded onto trucks and transported to the surface to the processing plant, where it is crushed, screened, stockpiled and dried. Finally, the material is passed through cross-currents designed to remove the lighter flakes from denser ones; crude vermiculite appears as golden-brown flakes, and its grades are classified depending on particle size. This scale ranges from coarse grades at 8mm to 2.8mm, to the finest grade at 0.710mm to 0.250mm.
Remarkably, heating vvermiculite expands the material to many times its original size. This process is called “exfoliation”, and is carried out commercially to prepare the material for use. These uses are extremely varied, from insulation and fire proofing to soil preparation, brake linings and the absorption of hazardous liquids.
With so many resources passing through their systems, and at such impressive quantities, Palabora’s mines are a constant hub of activity: “The mine practices full calendar operations, with 24-hour workdays, 365 days per year. We utilize 3-hour by 8-hour shifts per day, keeping the underground abuzz with focused activity at all times. Production, maintenance and service activities are carefully scheduled to obtain maximum benefit from the footprint, fixed plant and production machinery; and optimal output from our competent work teams.”
With such constant activity in a high-risk heavy industry, maintaining safety standards is just as importance to Palabora as the purity of their product. As well as keeping high safety standards and regulations in place, focus is given to every one of their 2,200-strong staff. “Safety is personalised, with our teams practicing a ‘high-care’ attitude towards all team members. Employees are also encouraged through extensive training and operational guidelines to be directly responsible for their own safety.”