First published in Cleantech magazine - Fuel Cell Special, Sept/Oct 2010
The mining industry is a major energy user and mining companies are increasingly focusing on both energy efficiency measures and cost effective ways of generating power – including fuel cells.
By Anne McIvor
We hear much about the challenges surrounding the use of coal as an energy source, less about the use of energy in the extraction of coal. However, the resource extraction industry, which includes drilling for oil and gas as well as mining for minerals and metals, is recognised as a major energy user and accordingly a significant emitter of greenhouse gases.
Mining is a massive industry involving a diverse range of energy intensive processes such as excavation, mine operation, material transfer, mineral preparation and separation. The local environmental impact of mines, many of which are located in remote areas, has been a topic of concern to environmentalists for many years – and mining companies have worked to address issues such as water quality. The sustainability reports of the major mining companies frequently address the issue of water. Newmont, for example, discusses the management of excess water produced in mines such as Batu Hijau in Indonesia or Minera Yanacocha in Peru – which in some cases is used for agriculture or for generating electricity.
The high energy consumption of the mining industry means that the potential for generating electricity as a by product of the process of mining is an attractive proposition. South Africa’s Department of Minerals and Energy (DME) estimates that the mining industry uses 6% of all the energy consumed in South Africa. In Brazil, the largest single energy consumer is mining giant Vale, which accounts for around 4% of all energy used in the country. In the US State of Colorado, mining has been estimated to account for 18% of total industrial sector energy use, while overall in the US it is calculated that the mining industry uses 3% of industry energy.Energy costs are estimated to represent more than 15% of the total cost of production in the mining industry in the US. This statistic alone might be expected to be sufficient reason to justify a reduction in the use of energy – but there has been little evidence that this is the case. The mining companies typically appear to pay only limited attention to cost levels in boom times. The case for implementing energy efficiency measures has received a boost with the onset of the global recession and corresponding decline in commodity prices. And it is an issue in regions where there is a shortage of energy. Mines in northern Chile have reduced power consumption to avoid the introduction of rationing, so energy security is clearly rising up the agenda as an issue – but typically regulatory pressure is a much stronger driver for mining companies to take action than economics.
Governments, especially in countries with large mining sectors, are imposing standards for energy efficiency. Australia’s miners are obliged to comply with the Equipment Energy Efficiency (E3) programme for energy efficiency. In South Africa, the DME set a target in 2007 for the mining industry to reduce energy demand by 15% by 2015: 32 South African mining and industrial companies have now signed up to an energy efficiency accord with the DME, on a voluntary basis.
Whatever the drivers, a host of companies are committing to implement energy efficiency measures. AngloGold Ashanti promised in 2008 to cut the energy used in producing an ounce of gold by 15% in the short to medium term. It has focused on reducing compressed air consumption at its deep underground South African operations, and has achieved a 30% reduction in compressed air use since 2004 using technologies including off-peak pressure reduction, optimal compressor scheduling and leak repair strategies.
Anglo Platinum and Gold One, meanwhile, have been using water rock drills, which consume less energy than compressed air drills, since 2008, according to pump manufacturer Cemo Pumps, which supplies the Crown V4 micro hydropower system.
Lonmin has identified energy security as a key issue, in the context of energy shortages faced by South African mining industries. To address energy security, Lonmin has set a target to improve its energy fficiency by 10% by 2012, based on 2007 efficiency levels.
Rio Tinto is developing the Mine of the Future™, a robotic mine at the West Angelas iron ore mine in Pilbara, Australia. The mine will rely more on remote controlled equipment and is developing energy efficient solutions. Rio Tinto is developing mining technology jointly with GE through the latter’s Ecomagination programme and has collaborated with the Rocky Mountain Institute to reduce energy use.
Technology developments are facilitating the introduction of energy efficiency measures in the mining industry. In exploration, developments include non-invasive technologies such as remote sensing, which can minimise exploratory digging and drilling. In excavation, new technologies include the use of adjustable speed drives (ASDs) in applications with highly varying load requirements.
Companies working on innovations for the mining industry include Siemens VAI, which has developed drive technology for rolling mills, alternating-current drive systems for the heavy trucks used in opencast mines (which ensure that diesel engines run within their optimal speed ranges) and gearless drive (GD) systems. Energy saving motors have been mandated in the US, China, Canada and Australia, and Siemens VAI has developed low-speed applications, such as grinding mill drives, mine winder drives, bucket chain excavators and drag chains. The company argues that, if every electrical drive worldwide was brought up to the latest technology standards, the annual energy savings would be in the region of 130 TWh (financial cost: €9 billion). In 2008 Siemens introduced conveyors equipped with variable frequency drives to open pit mines owned by Neyveli Lignite Corporation, in Tamil Nadu, India - the first project in India to be equipped with variable frequency drives.
Siemens is also working on applications involving pumps, condensers, conveyors and refrigeration, and measures such as the replacement of mechanical throttles with frequency converters. In applications where large loads are moved or where a lot of braking energy is needed (hoisting devices, rolling routes, conveyor belts, etc) savings can be achieved through the use of frequency converters with regeneration capability.
Elsewhere, Magnetek recently introduced its M-Force 240/480/575-volt general purpose AC variable frequency drives for mining applications, designed for use with pumps, fans and conveyors in mining environments.
A number of mining companies are working on the development of low emission technologies for the industry - either directly, or through funding for research. BHP Billiton committed to spending US$300 million between 2008 and 2012 to support the research and development of low emissions technologies. Vale established the Vale Technology Institute (ITV) in 2009 to promote scientific research and technological development. Amongst its objectives is the generation of know-how for a sustainable mining industry. Research fields to be developed at the research centre in Belém (Pará) include mining and sustainable engineering.
Mining companies sometimes evolve into electricity providers for local communities. AngloGold Ashanti refers to “community expectations that the mine is responsible for the electrification” of the town of Siguiri, next to its Siguiri mine.
Some companies go a step further and become directly involved in electricity generation. Rio Tinto, for example, has its own hydropower generating facilities with combined generating capacity of over 3,500MW. Control over electricity generation tends to be part of an internal risk management strategy. Vale, a major investor in power generation in Brazil, comments that this is part of a strategy to “systematise information to help us take strategic decisions and reduce risks” – to protect the business from price volatility and minimise regulatory, climatic and supply-side risks.
Vale has investments in a host of different energy sources, including natural gas and petroleum. It is, however, committed to developing projects to boost the use of renewable energy sources and generates a significant portion of its energy requirements through hydroelectric power plants, owning stakes directly in eight hydroelectric plants.
Vale Soluções em Energia (VSE), a partnership between Vale and BNDES, the national development bank of Brazil, is developing power generation technologies, equipment and systems, with a focus on environmentally sustainable processes and the use of renewable energy sources. VSE’s technology centre at São José dos Campos Technology Park in the state of São Paulo focuses on technological innovation in power generation; high efficiency solutions for reducing overall costs; and environmentally sustainable solutions, especially renewable energy sources.
VSE has a particular focus on opportunities in the distributed power distribution market and has an investment programme of US$720 million for this area. It has a joint venture with Scania of Sweden for the development of ethanol and gas-powered industrial engines for the Brazilian market. A series of single-speed stationary engines is being developed, intended for use in the agriculture and mining industries, to generate electricity and drive pumps and compressors – a market estimated at 3,000 engines per year in Brazil alone.
Separately, Vale has invested in biodiesel company, Biovale - a joint venture with Biopalma da Amazônia S.A. Biovale will produce a 20% biodiesel/80% mineral diesel blend which will power its entire fleet of 216 locomotives in the North System, as well as heavy machinery at the Carajás mines.
Elsewhere, Lonmin is investigating alternative, low emission energy sources including options for geothermal energy use and bio-energy generation.
In the US alone, according to the US Environmental Protection Agency (EPA), 400 mines operate 8,300 diesel powered vehicles. In addition to the greenhouse gas emissions from the diesel or the fossil fuel energy dependency, the exposure of miners to high concentrations of particulate matter is also a major environmental concern. Fuel cell-powered mine vehicles offer the potential for widespread use in the mining industry in the future.
Placer Dome tested a fuel cell-powered underground mining haulage vehicle, which was developed by the Fuelcell Propulsion Institute and Vehicle Projects/Vehicle Projects Inc. in 2002. The four-ton locomotive, developed as part of a $1.2 million project which was funded by the US Department of Energy, was powered by PEM fuel cells with reversible metal-hydride storage. The hydride storage system and ‘balance of plant’ was designed by Sandia. The vehicle was tested at the Val-d’Or mine in Quebec, Canada and provided a much superior performance to a battery vehicle. The locomotive then worked at Placer Dome’s Campbell mine in Red Lake Ontario. Placer Dome was subsequently acquired by Barrick Gold, which has invested in wind energy in Chile and Argentina, and hydro electric power in Tanzania.
More recently, Anglo Platinum (Angloplat) has led the way in the use of stationary fuel cell engines in mining, for power generation. Angloplat launched a fuel cell demonstration plant in Limpopo, South Africa last year which produces 200kW of electricity from coal-bed methane.
Fuel cells can use a variety of feedstreams, particularly hydrogen, but also ammonia, ethanol, methanol and liquid petroleum gas, to generate electricity. If methane is present at the mine – either as coal bed or coal mine methane (CBM, CMM), or as a product of underground coal gasification (UCG) – then the hydrogen feedstream can be derived from reforming the methane or as a by-product from any gas-to-liquid process undertaken. Otherwise a fuelling infrastructure will have to be deployed.
Earlier this year Angloplat’s Platinum Group Metals Development Fund (PGMD) formed Clean Energy Incorporated, a partnership with Altergy Systems of the US and the South African Department of Science and Technology. Clean Energy will focus on stationary fuel cells for the South African market, initially as a distributor and ultimately as a manufacturer. The telecommunications sector is one of the first target markets. Of the world’s total platinum group metals, 75% are located in South Africa, and the South African Government is keen to develop a local hydrogen economy to help transform the country’s mining industry into an exporter of processed minerals. The initiative is considered by Science and Technology Minister Naledi Pando to be in line with the “… goal of promoting SA as a source of world-class, high technology transfer and infrastructure opportunities”.
While most mining companies are now focusing on energy efficiency, to meet regulatory requirements, if not because of economics, the more far-sighted are moving beyond their traditional business and becoming producers of energy in their own right. Typically the focus is on distributed energy, which is also appropriate for their own needs. We can expect to see growing numbers of mining companies investing in clean technologies, including fuel cells, over the coming years.
Related Articles: Mining and Energy Case Study: Anglo Platinum
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