Siemens VAI Metals Technologies has received an order from Talleres y Aceros S.A. de C.V. (Tyasa), a Mexican steelmaker, to supply a new compact steelmaking plant with a capacity of 1.2 million tons of steel per annum for its Ixtaczoquitlan site. The value of this order lies in the mid double-digit million euro range. The heart of the plant is a Simetal EAF Quantum electric arc furnace. This new furnace design reduces the specific conversion cost for the electric production of steel by around 20 percent. The project also involves the provision of secondary steelmaking facilities and a combination continuous caster. It is scheduled to be completed by the middle of 2013.
Oscar Chahín Trueba, CEO of Tyasa, said, «We’re looking forward to becoming the world’s first steelmaker to be able to run a Quantum electric arc furnace. Without a doubt, this fact will position us as a reference company for other companies in the world and will also consolidate us in the international market, especially in Latin America. The complete solution offered by Siemens for the compact steelmaking plant has convinced us, and we’re expecting to gain significant advantages in operating costs, especially from the new electric arc furnace.»
For Tyasa’s new compact steelmaking plant in Ixtaczoquitlan in the Mexican state of Veracruz, Siemens will supply a Quantum electric arc furnace with a tapping weight of 100 tons, as well as secondary steelmaking facilities. These include a 100 ton double ladle furnace and a 100 ton double vacuum degassing plant. The plant will have a capacity of around 1.2 million tons of killed, low, medium and high-carbon steels per annum. The steel it produces will be cast in a six-strand combination continuous caster into billets with cross-sections ranging from 130×130 millimeters to 200×200 millimeters, as well as rough profiles with dimensions of 300x200x80 millimeters. The new plant will enable Tyasa not only to increase its production capacity substantially but also to widen its range of products.
The key component of the compact steelmaking plant is the Simetal EAF Quantum electric arc furnace newly developed by Siemens. This combines proven shaft furnace technology elements with a new scrap charging process, an efficient preheating system, a new tilting concept for the lower shell, and an optimized tapping system. This enables tap-to-tap times of 36 minutes to be achieved. The electricity consumption, at just 280 kilowatt-hours per ton, is considerably lower than that of a conventional electric arc furnace. This, coupled with the lower consumption of electrodes and oxygen, gives a total advantage in the specific conversion cost of around 20 percent. Total CO2 emissions can also be reduced by up to 30 percent per ton of crude steel in comparison to conventional electric arc furnaces.
A dry dedusting system with evaporation cooler, a quenching tower, an automated pulse-jet-type filter-bag house and an induced draught fan will be installed in order to minimize the emissions of the steel works. The dedusting system will clean the offgases from the electric arc and ladle furnaces, as well as from the material handling system. The dedusting system will have a cleaning capacity of around one million cubic meters per hour, and reduce the dust content of the offgases to less than ten milligrams per cubic meter.
The project also includes a double circuit water cooling system for the electric arc furnace, the secondary steelmaking facilities and the casting plant. Drinking, process and extinguishing water circuits will also be installed. It is also planned to construct a water treatment plant with mechanical and chemical stages. This will enable the total water requirements of the steel works to be optimized.
The scope of supply from Siemens is rounded off by electrical and automation systems and components. These include the power distribution, the basic and process automation, as well as process models for the steel works and the continuous caster.
Talleres y Aceros S.A. de C.V. was founded in 1985, and is privately owned. The company currently has two production sites, one in Ixtaczoquitlan near Orizaba in the State of Veracruz, the other in Mérida, the capital city of the Mexican State of Yucatán. Tyasa produces around 450,000 tons of billets per annum, which are then further processed in its own rolling mill to make wire and bar steels, as well as building materials, such as rebars and nails. The total capacity for rolled products is around 700,000 tons per annum.