A. Ahlstrom Corporation

A. Ahlstrom Osakeyhtio

Stig Petersson

Rolf E Malmstrom

A method and apparatus for treating zinc concentrates in order to recover zinc. The method includes an oxidizing and smelting stage (10) and, subsequent to the smelting stage, a fuming stage (20) in which the zinc-oxide-containing slag formed in the smelting stage is so reduced as to remove the metallic zinc with the exhaust gases (28). Part of the reduced slag is discharged during the fuming stage, another part (32) is recirculated to the smelting stage. In accordance with a preferable method, the slag is reduced in two successive fuming stages (20, 40). In an apparatus according to the invention, the slag circulation between the fuming and smelting stages is facilitated by overflows arranged in the partition walls (19) between the various stages.

Apparatus for treating zinc concentrates

A catalyst bed for conducting exothermal reactions between gases and/or other fluids is disclosed. The catalyst bed includes at least two cooling elements arranged in parallel relationship with each other. A space is thereby defined between the two cooling elements, and one opening at each opposite end of the cooling elements is also defined by the arrangement of cooling elements. The space created is adapted to receive a catalyst mass through either of the openings. The cooling elements cool the gases and/or other fluids, as well as the catalyst mass to keep the reaction temperature low enough to maintain a desired state of equilibrium.

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Skelleftehamn, Sweden

Stig Petersson