Siemens Supplies Gearless Mill Drives for Aurox Iron-Ore Project in Western Australia

The two mills are to be equipped with “frozen charge shakers” which allow the controlled removal of charge stuck to the sides of the grinding pipe. The order has a volume of more than 20 million euros and the project is scheduled for completion in the third quarter of 2010.

Aurox is currently developing the Balla-Balla magnetite deposits in the Pilbara region of Western Australia. FLSmidth & Co. A/S, a Danish company, is building an ore processing plant with an annual capacity of six million metric tons of iron ore concentrate. It is also installing loading facilities in nearby Port Headland. The ore processing plant has been designed so that its processing capacity can be expanded to up to ten million metric tons a year.

For the plant's two ore mills Siemens is supplying gearless motor drive systems which are supplied with power by direct converters. The SAG mill has a diameter of 34 feet and will be fitted with a 14-megawatt drive, whereas the 26-foot ball mill will have a 17-megawatt drive. The drive systems are based on “Simine Mill GD”, a solution specially developed for ore mills by Siemens. The variable-speed drives will be controlled with the help of the patented transvector-control principle. This makes it possible to set the operating point of a drive easily and precisely to match varying requirements.

Soft stopping and restarting reduces wear. Due to the lack of gears, maintenance and repair costs are considerably lower than for conventional drives while shorter downtimes and longer service intervals increase availability. Moreover, gearless drives are more efficient and consume less energy, reducing operating costs in the process. The ore mills are to be equipped with the “frozen charge shaker”. Developed by Siemens, this procedure is used for the controlled removal of frozen charge which has become stuck to the inner wall of the mill. The frozen charge no longer needs to be removed manually in the pipe. This reduces downtimes, increases availability and avoids damage to the mill caused by material falling down in an uncontrolled manner. “eWD” (electronic Web-based Documentation) ensures central availability of the entire plant documentation in the operator control and visualization system. All relevant documents are kept centrally in electronic form. A context-sensitive link to the operator control and visualization system with automatic linking of documents allows the operating personnel to maintain an overview at all times. The integrated search engine ensures that important information can be found quickly. The documentation can also be updated very easily and other documents added when required, including the documents of other project partners.

The Siemens Industry Sector (Erlangen, Germany) is the world's leading supplier of production, transportation and building systems. Integrated hardware and software technologies combined with comprehensive industry-specific solutions enable Siemens to enhance the productivity and efficiency of its customers in industry and infrastructure. The Sector comprises six Divisions: Building Technologies, Industry Automation, Industry Solutions, Mobility, Drive Technologies and Osram. In fiscal 2007 (ended September 30), Siemens Industry generated sales of approximately EUR40 billion (pro forma, unconsolidated) with around 209,000 employees worldwide.

With the business activities of Siemens VAI Metal Technologies, (Linz, Austria), Siemens Water Technologies (Warrendale, Pa., U.S.A.), and Industry Technologies, (Erlangen, Germany), the Siemens Industry Solutions Division (Erlangen, Germany) is one of the world's leading solution and service providers for industrial and infrastructure facilities. Using its own products, systems and process technologies, Industry Solutions develops and builds plants for end customers, commissions them and provides support during their entire life cycle.