RATH: Technically demanding relining of a tilting hearth-type melting furnace completed at Aluminium GmbH Nachrodt in only 21 days

Published 11th October, 2023 by Zahra Awan

It is a pivotal element in the aluminum industry, without which nothing works: The melting furnace. For almost four decades now, RATH has been offering sophisticated refractory solutions for the optimal operation of aluminum melting furnaces. Such a solution has now been developed also for the relining of a hearth-type melting furnace in the aluminum smelter of Aluminium GmbH Nachrodt (AGN) in the Sauerland region of Germany: Removal and relining were successfully completed in just 21 days.

An optimal, long-lasting refractory lining of the melting furnaces is an essential component for a melting plant to work with highly efficacy. Thanks to more than 130 years of experience in refractory technology, RATH possesses extensive expertise and has developed a comprehensive range of refractory and thermal insulation products for the aluminum industry. Expertise from which Aluminium GmbH Nachrodt, too, is now benefiting.

The requirements were demanding: The removal and relining of a tilting hearth melting furnace was to be completed as rapidly as possible during the 2022 Christmas holidays and turn of the year. “An additional major challenge of the project: The burner technology in the top furnace was simultaneously rebuilt with major interventions in the steel structure of the furnace”, explains Stephan Holze, Sales & Application Consulting, RATH, illustrating the special challenges of this project.

Mission accomplished – in just three weeks!

The specialists of the internationally active refractory manufacturer succeeded in carrying out the technically demanding lining in only three weeks. 75m³ were lined with a total of 115 tons of refractory material – 17 tons of which in the form of precast concrete components weighing between 230 and 530 kilograms. The floor, ramp, bridge and lower side wall were lined with the proven component concept. Furthermore, Nachrodt relied on RATH's experts when it came to heating: The furnace was heated up externally, with concomitant thermographic monitoring as well as additional control of the heating depending on the steam pressure in the concrete area in order to achieve optimum quality.

Major benefits for Aluminium GmbH Nachrodt
Now the customer benefits from longer service life of the refractory lining, high operational reliability, low wear, and better cleaning. The prefabricated, heat-treated and factory-tested components are likewise very beneficial: These ensure higher quality than possible with on-site lining. In addition, assembly errors that could lead to hidden damage can thus be excluded. A further benefit: All the components used in the bath area of the furnace have very smooth surfaces with minimum open porosity, which further increases resistance to infiltration.

Full-range supplier of services and products
RATH is not only a full-range supplier in terms of consulting and services, but also in the production of all the refractory materials required for all layers in furnace construction. As one of the few manufacturers in the refractory sector, the company produces the complete portfolio of refractory materials required for the refractory lining of a wide range of aluminum furnaces itself.