Mining the future – Rio Tinto's vision

Materials World magazine
,
1 Aug 2008

John McGagh, Head of Innovation at Rio Tinto, sets out his company’s vision for the future of mining. Michael Forrest reports.

Mining and agriculture are the base of our economies, so it is not surprising that emerging nations are driving demand for energy, food and manufactured goods. Not only are the populations of these nations, led by China and India, driving demand but the large infrastructure projects of urbanisation, power and transport require large quantities of mined commodities, from rare metals to cement.

Global demand

The scale of current and projected demand is unparalleled in the history of mining and poses severe challenges for the future. In China the movement of over 400m people to the urbanising areas of the east coast is unprecedented, as is the three-fold population increase over the past century to over 1.3bln.

However, it is not all about numbers. The ageing population in China is keen to have those consumer goods that they see on television and the Internet and that are freely available in the west. The same will apply to India in the future. Today 800m people have a consumer-orientated lifestyle typified by the populations of Europe and North America. This leaves 5,800m who may aspire to this way of life and, as a consequence, the demand for natural resources will be on a scale never witnessed before.

This is happening at a time when many of the larger mines are becoming exhausted and discoveries of large-scale mineral deposits are low. This is compounded by a proper regard for the environment and the restrictions this places on development.

Falling returns

These factors represent the same challenge to international mining company Rio Tinto as to the rest of the industry. The question of why this situation has arisen in the comparatively short time of less than a decade can be explained by a review of the industry in recent times. From 1983 to 2003, metal prices fell year on year at a rate of around 1.3% per annum. This lack of return made it difficult to attract investment funds for new mines, curtailed exploration, and, perhaps most importantly, made university candidates see the industry with an unattractive future.

Developments in the sector were mainly led by equipment manufacturers, who had a difficult job selling into a deeply conservative industry. This conservatism was driven by the need to reduce costs to meet falling prices, and was in itself a form of technological advancement.

A forecast of the likely demand for minerals and metals is shown in the graph of steel consumption that plots demand at stages of national economic development.

In primarily agrarian economies, such as India, steel consumption per capita is around 40kg per annum. In post-industrial societies where service industries are the economic mainstay, consumption is around 400kg/y. However, in those countries where industrialisation and urbanisation are in full swing, steel consumption can rise to around 1,000kg per capita, as seen in Korea and Taiwan. Chinese consumption is around 270kg per capita, or about one third of these levels, and consequently, if the scale of industrialisation is repeated, it will put massive strain on iron ore producers. It is not only steel that underpins industrial development. The compound annual growth rate for iron ore, aluminium and copper is around four per cent and is projected to double in demand by 2022.

Challenging future

Although ‘mine of the future’ is a somewhat abstract concept, the challenges are real. John McGagh, Head of Innovation at Rio Tinto, sees unprecedented demand at a time of maturing ore bodies and fewer large surface discoveries, an inevitable migration to underground working, lower grades mined and longer haul distances, and mounting energy constraints. In addition the next generation of ore bodies will bring inherently complex mineralisation. These challenges will be set against shareholder and society demands for lower environmental impact and a reduction in the carbon footprint of mining.

McGagh maintains that copper is also going underground. There is an enormous demand for copper to support the needs of the developed economies and growing requirements from the emerging economies. He notes that companies have been mining surface ore bodies for a long time (in some cases for over 100 years), resulting in depleted resources. He says there is a need for a step change in technology to enable underground shaft operations of over 100,000t capacity per day, with dozens of shafts and [kilometres] of tunnels to support the ‘mega block caves of the future’.

Central research

Rio Tinto is commissioning research into a number of areas that will be part of the mine of the future. ‘The company has deliberately refrained from building large in-house centres to handle innovative work, says McGagh. ‘The world is increasingly an interconnected and interdependent place and we believe our core skill lies in identifying the challenges, visioning the mine of the future and coordinating the resources to best attack the problem.’

One of these centres is Imperial College, London, UK, where Rio is funding research to improve flotation, leaching and rock mechanics. Other topics to be undertaken elsewhere include automation, online drill sampling and low energy communition. It is the latter area where significant energy savings may be obtained as banging rocks together to release minerals is only one per cent energy efficient. Large-scale underground copper mining block caving, where large blocks of ore are undercut causing them to break or cave under their own weight, may be expanded to make the breakthrough in scale required to meet targets.

Rio Tinto has put this vision into practice at its iron ore operations in the Pilbara region of Western Australia. Located 1,200km north of Perth, the area and climate present a number of logistical challenges that are being met with innovative technologies.

Rising production

Beginning with the discovery of the Pilbara in the 1960s, Rio Tinto’s iron ore production has risen incrementally until the millennium, when increasing Asian demand triggered rapid expansion. Today annual production is some 200Mt. Not only have mines been expanded by the company, but Rio Tinto also has one of the largest landholdings in the Pilbara and its exploration programmes have identified many new deposits. In addition, significant past investment in ports and railways has enabled the company to plan ahead and iron ore production is set to rise to 320 Mt/y in the coming years and later 420Mt/y.

To obtain this level of production new technologies are being tested in the West Angelas mining area. Most visible of these are driver-less trucks to transport mined ore to processing plants using high accuracy in-pit GPS. The routes are predetermined by mining schedules. Rio Tinto has placed a large order for these trucks with Komatsu, headquartered in Tokyo, Japan, who are pioneers in this field.

Drill rigs have also been automated with in-house technology to allow rock recognition during drilling, as has blasting, and trials for automating loaders are underway. These technologies reduce the time cycle of mining (drill, blast, load, transport) beyond human reaction time.

One objective is to automate mining so that ore blending can take place during mining rather than relying on large blending plants. Rio Tinto’s Pilbara iron ore blend, launched in 2007, has been well received and has allowed a substantial increase in mineable reserves.

This will all take place with due regard to the environment. Practices such as moving mine accommodation underground, both reducing its footprint and lowering energy costs, and converting diesel trains to run on local natural gas will all help. In addition, much of the operations in the Pilbara will be run from a command centre located near Perth airport. Using high-speed links all aspects of the operations will be monitored, reducing the number of personnel in the Pilbara desert, and therefore the impact.

‘This Pilbara test bed will run for just over a year before Pit A comes on stream at the end of 2008,’ says McGagh. ‘Technologies proven here will be rolled out over the entire Rio Tinto iron ore operations.’

Further information: Rio Tinto