Glencore’s Horne Smelter is a custom copper smelter located in Rouyn-Noranda, Canada. Over the past decade, substantial development work has been made to modernize its process. In line with the internal development of the Noranda Reactor (1970s) and Noranda Converter (1990s), a new approach using ladle metallurgy has been developed for converting and refining of semi-blister copper in a single step into anode copper, thus replacing the pyro refining vessels (Peirce-Smith converters) and anode furnaces. Extensive development work and piloting steps were conducted over the last decade to conclusively demonstrate the performance of this technology, allowing for its full-scale implementation. Under the name of Aeris, the project is focused at increasing efficiency and improving the smelter’s environmental performance. The new process is planned to be commissioned in 2027. This paper presents the rationale behind the technology selection, the development of the application of ladle metallurgy in copper converting and refining, and the overall smelter modernization plan.