Jan 21 2011
Siemens VAI Metals Technologies received an order from the Brazilian steel producer Usinas Siderurgicas de Minas Gerais SA (Usiminas) to install two Intensive Mixing and Granulation Systems in sinter plants located at the company's Cubatão and Ipatinga steelworks in southern Brazil.
This solution will enable a high portion of pellet feed, which is normally not suitable for the sintering process, to be used in the company's sinter plants. The project will be jointly implemented on a full turn-key basis by the Metals Division of Siemens Ltda in Belo Horizonte, Brazil, and Siemens VAI headquarters in Linz, Austria. The value of the order is a low two-digit million euro figure. Start-up of both systems is scheduled for late 2011.
Inside view of vertical-type intensive mixer from Siemens.
A trend that can be noted in the mining of iron ores worldwide is that the portion of fine and ultra-fine ores is continually increasing. Existing sinter plants are not designed to efficiently process larger quantities of undersized ore fractions. The Intensive Mixing and Granulation System from Siemens VAI was designed to enable a much higher portion of pellet feed to be included in the sinter raw mix without adversely affecting production operations. This solution, which can be installed in both new and existing plants, allows a thoroughly homogeneous sinter raw mix to be achieved, which is the basis for high sinter quality and a stable sintering process.
The Siemens project scope includes complete engineering, civil works, steel construction, and the supply of mechanical equipment, electrics, automation and utilities. The mechanical equipment will comprise two intensive mixers outfitted with vapor removal, the belt-conveyor and pneumatic-transport systems, and secondary dedusting facilities. The existing granulation drums will be modified to ensure optimum granulation of the sinter raw mix. Advisory services for erection and commissioning, assisted operation, in addition to personnel training, will also be provided.
The Usiminas Group is the largest flat-steel producer in Brazil. Currently, the company is in the process of partially substituting purchased iron ore with its own ores sourced from its mining complex in southern Brazil. The Usiminas mines will generate a large percentage of ultra-fine ores, which normally would have to be pelletized prior to charging in a blast furnace. In order to enable up to 25% of the ultra-fine ores (grain size: < 0.1 mm) to be used in the company's existing sinter plants, special treatment of the entire sinter raw mix is required. For this reason, the company decided to install two Intensive Mixing and Granulation Systems, which will process the sinter raw mix for the Sinter Plant No. 3 at the Cubatão (Sao Paulo) steelworks, and the Sinter Plants Nos. 1 and 2 at the Ipatinga (Minas Gerais) site. The total output from all three sinter plants is nearly seven million tons of sinter per year.
Intensive mixing and granulation systems from Siemens VAI are successfully operating in the sinter plants of voestalpine Donawitz GmbH, Austria, and at Dragon Steel Corporation, Taiwan.