May 11 2010
In future, mining companies will have to invest more heavily in environmental protection and occupational safety in order to maintain their future viability and long-term profitability. As Bernd Zehentbauer, Senior Vice-President of Mining Technologies at Siemens VAI, said, “Water shortages, rising energy costs and increasing social responsibilities in mining areas increasingly necessitate additional measures which affect profits. However, energy efficiency and water treatment technologies are helping to maintain competitiveness.
We use electric drives in trucks, shovels, conveyor systems and ore-crushing mills to reduce energy consumption and therefore ease the demands on power supply systems which are already very tight in many mining areas. Broadening the technology portfolio to include wastewater treatment is helping Siemens to ease the problem of water shortage. We use Manufacturing Execution Systems (MES) to analyze operating data along the production chain. This not only creates transparency, but also helps management to make the right decisions that will lead to efficient and environmentally acceptable operations.”
Many mining areas are suffering from a growing shortage of energy. This is already affecting production in South Africa and Chile. Mines in northern Chile are reducing their power consumption to avoid the introduction of rationing. Zehentbauer emphasized that, “the use of energy-efficient drive solutions is becoming more and more crucial to achieving sustainable production, and it also helps to save energy.” Siemens has developed alternating-current drive systems for the heavy trucks that transport the material at opencast mines. They ensure that diesel engines run within their optimal speed ranges. Compared with conventional diesel drives, these diesel-electric drive systems not only have a lower environmental impact, but also save fuel and cut operating costs.
Gearless drive systems (GD) also help to reduce energy consumption. During the last 30 years, Siemens has been continually developing its GD systems, and has gained substantial experience with low-speed applications, such as grinding mill drives, mine winder drives, bucket chain excavators and drag chains. Zehentbauer sees additional potential in combining belt conveyors and GD technology, “Belt conveyors have proven to be a very efficient and cost-effective means of transporting bulk material in mining applications, irrespective of the distances, quantities and terrain involved. When it comes to energy efficiency and availability, gearless drives are a logical step in the further development of material handling systems.” However, measures to reduce energy consumption have to take more than the individual systems into account. Zehentbauer added, “It is important to have a comprehensive energy management system.” This means that Siemens now considers the complete drive train and the entire plant automation together, because both the drive and automation levels make an important contribution toward energy efficiency and lower operating costs.
Apart from the energy issue, a shortage of water is preventing the expansion of production in many of the world's mining areas. Zehentbauer said, “Housing, agriculture, industry and mines are competing for water everywhere to an ever greater extent.” Siemens' technical solutions for treating water, such as membrane systems, are helping to make better use of water, and thus ease the strain on the environment. The takeover of Industrial Process Machinery (IPM) – based in Manchester, New Hampshire, USA – has widened Siemens portfolio for dewatering raw material concentrates. Over 100 IPM high-performance filter presses are currently in use. Short press cycles and fast-moving filter plates ensure cost-effective operation. The press cakes they produce have such a low moisture content that there is no need for additional thermal drying plants. This considerably reduces energy consumption which, in turn, also lowers operating costs.
Zehentbauer explained that, “The social challenges and environmental policy requirements regarding energy consumption and water supplies are imposing ever greater costs on opencast mining operations, and this calls for additional investments.” In order to increase production and, at the same time, minimize rising costs, companies need to adopt new approaches, and that means optimizing their operational procedures. Zehentbauer said, “It is not enough just to optimize one area of operations. On the contrary, downtimes have to be reduced, materials delivered even more quickly, and maintaining material quality also has to be given top priority.” Siemens MES offer a solution that analyzes the machine and mining data of an opencast mining operation, and reveals the strengths and weaknesses in the overall production and operational processes.
Zehentbauer continued, “This real-time transparency enables management to control operating processes better, and to assess the cost-effectiveness of their various production plants.” MES can be used to issue instructions to operating personnel as well as helping maintenance teams to monitor risks, and thus prevent damage to the plant. This reduces plant failures and avoids unscheduled production stoppages, which not only boosts production, but also lengthens the service lives of the production facilities and the field equipment.