Boliden Aktiebolag

Bengt O Rudling

Stig A Petersson

Leif Johansson

The invention relates to a method for recovering the metal values from materials containing at least one of zinc and tin, by smelting the starting materials under oxidizing conditions and reducing the resultant molten bath. The starting materials are first smelted in a furnace while adding flux, to form a slag which is sluggish at selected reduction temperatures and has a low lead contents. The reduction process is carried out while charging solid carbonaceous reduction agent and optionally also sulphur- and/or chlorine-donor material to the slag. The reduction agent and optionally supplied donor material is brought into suspension with the slag, and this suspension is sustained at least during the latter phase of the reduction period, at which the lead content of the slag has fallen to beneath about 1-2%, during which phase the reduction of zinc and tin takes place. Zinc is recovered from the furnace in the form of zinc vapor, while tin optionally is removed as volatile tin sulphide, chloride or oxide, and lead and any other metal values present in the starting materials are recovered as a molten lead phase.

Growing community of inventors

Skelleftehamn, Sweden

Bengt O Rudling