Aludium is investing €20 million in an Ecomelt PS-275 multi-chamber melting furnace for its facility in Amorebieta, Spain, which includes hot and cold rolling capacities, as well as strip processing and a casthouse for rolling slabs. The site produces sheet primarily serving the building and construction, distribution, and specialities sectors. The new furnace, supplied by Hertwich Engineering, will be able to melt up to 55,000 tonnes of painted or thin scrap annually, reducing the company’s need for rolling slab from external suppliers.
“The investigation team visited a number of similar installations and concluded that the multi-chamber furnace was the best option for Aludium,” said Mario Allet, program director, Aludium. “The new facility will complement the rotary furnace which was installed in Amorebieta during 2017. However, there will still be room for future investments to support Aludium’s increasing metal needs as we realize our growth roadmap.”
To be able to process the growing amount of return scrap effectively and economically, the multi-chamber furnace is specifically designed for scrap with the highest contamination rates — including loose and packaged strip or foil scrap, coils, wire, etc. that may be contaminated by oils, lacquers, plastic residues, rubber, or other coatings. It comes with a preheating shaft into which the scrap is fed from above through a material lock. Hot gases flow through the charged material within the shaft from the bottom upwards, and the pyrolysis gases produced during the process are combusted in the main chamber in a controlled manner. Therefore, external after-burning is not required. At the lower end of the shaft, the completely pre-heated and decoated material is immersed in the melt bath, which is moved by a liquid metal pump. The scrap material is melted instantaneously with minimal melt loss. The furnace also has a 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. The throughput of the furnace is 275 tonnes per day.
By using pyrolysis gases, the energy consumption can be reduced to some 300 kWh/tonne (depending on the scrap input). This reduces operating costs and reduces emissions (CO2, CO, NOX, dioxins, VOC) in order to contribute to an environmentally friendly furnace operation.
The multi-chamber furnace will operate continuously and will produce large volumes of 3xxx and 5xxx alloys. Importantly, the quality of the cast products will meet the most demanding specifications in compliance with the ISO 9001 standard.
In addition to increasing capacity, the new multi-chamber furnace, together with other investments, will also increase Aludium’s sustainability as it reduces the company’s need for primary aluminum metal by around 75,000 tpy. Compared to primary metal production, recycling aluminum reduces energy consumption by 95% or 14 MWh/t Al. The introduction of the multi-chamber furnace is expected to reduce the company’s CO2 emissions by 250,000 tonnes annually.
During the installation of the new furnace, the company also plans to adapt the casthouse to serve its furture needs. The existing scrap yard will be enlarged, and a new 65-tonne scrap holder will be installed. The company’s casting Pit #3 will be enlarged to allow five sheet ingots to be cast in each drop. The unit will be further optimized for safety with features such as a hands-free casting machine. The entire system will also be designed to comply with OHSAS 18001 and European standards.
The company noted that its Cindal R&D facility will be closely involved at all stages of the project to optimize the chemistry of the slabs. Researchers from Cindal have already performed a series of trials to ensure that the chemistry of the slabs fulfill all requirements.
The new multi-chamber melting furnace will go into operation in spring 2019.