In the early 1990s, technical personnel from the then Union Miniére worked with MIM Holdings personnel to develop an ISASMELT-based process to treat scrap materials and residues containing copper and lead. Union Miniére operated a smelter at Hoboken, near Antwerpen in Belgium, that specialised in recycling scrap non-ferrous materials. The test work program was undertaken using an ISASMELT test rig at MIM Holdings’ lead refinery, Britannia Refined Metals, at Northfleet in the United Kingdom.
A demonstration plant was designed by MIM Holdings personnel and operated for several months at the Hoboken smelter site. The new smelter was commissioned in the final quarter of 1997 and in 2007 was treating up to 300,000 t/y of secondary materials. The installation of the ISASMELT furnace replaced a roasting plant, a sinter plant, 1 of two sulfuric acid plants, a copper blast furnace and four Hoboken converters. It substantially reduced operating costs at the Hoboken smelter.
Umicore's Hoboken plant uses a two-step process in a single furnace. The first step involves the oxidation of the feed to form a copper matte and a lead-rich slag. The slag is then tapped and the remaining copper matte is then converted to blister copper. The lead-rich slag is subsequently reduced in a blast furnace to produce lead metal, while the copper is refined and the contained precious metals recovered.