The long-standing aluminium rolling mill in Amorebieta, Spain which has been operating under the name Aludium (www.aludium.com) since 2015, has ordered an Ecomelt PS-275 multi chamber melting furnace with preheat shaft for clean and contaminated scrap from Hertwich Engineering, an SMS Group company. This investment sees the plant adapting to the growing amount of recycled material available. The new multi chamber melting furnace will go into operation in spring 2019.
The Amorebieta plant includes hot and cold rolling capacities as well as strip processing and a casthouse for rolling slabs. Contrary to the general market trend towards "Automotive" and "Aerospace", the strategic focus here is on the sectors "Building and Construction", "Distribution" and "Specialities".
To be able to process the growing amount of return scrap effectively and economically in the casthouse, the melting capacity is increased by investing in a modern multi chamber melting furnace of the type Ecomelt-PS275. The throughput is 275 tonnes per day. Loose and packaged strip or foil scrap, coils, wire, etc. are melted – each contaminated by oils, lacquers, plastic residues, rubber or other coatings.
Depending on the type and composition of the scrap, Hertwich offers different furnace types within the Ecomelt series. The PS type furnace ordered by Aludium Amorebieta is suitable for scrap with the highest contamination rates. It comes with a preheating shaft into which the scrap is fed from above through a material lock. The hot gases flow through the charged material in the shaft from the bottom upwards, and the pyrolysis gases produced thereby are combusted in the main chamber. By using pyrolysis gases (but also due to the advanced furnace design) the gas consumption can be reduced to some 300 kWh/tonne (depending on the scrap input). This reduces operating costs and the minimum emissions (CO2, CO, NOX, dioxins, VOC, no salt) contribute to an environmentally friendly furnace operation.
External after-burning is not necessary as all emerging pyrolysis gases are combusted in the main chamber in a controlled manner. At the lower end of the shaft, the completely pre-heated and decoated material is immersed in the melt bath moved by a liquid metal pump and is melted instantaneously with minimal melt loss.
As a further special feature, the melting furnace has a separate feed for scalper chips, which are fed into the furnace immediately after machining of rolling slabs and are also melted using the submersion melting process with the greatest possible yield.