Elkem Technology A/s

Elkem Asa

Inger J Eikeland

Jan A Aune

Thor Pedersen

Roald Gundersen

Ragnhild Jensen

Per Poppe

The present invention relates to a method for upgrading silicon-containing solid residues obtained after leaching of copper from copper-containing residues from direct synthesis of organochlorosilanes. Solid residue, optionally together with an oxidation agent, is supplied to a smelting furnace where the residues are melted and form a molten metallic phase substantially containing silicon and a calcium silicate slag and tapping of the molten metallic phase and an inert slag from the smelting furnace.

Method for upgrading of silicon-containing residues obtained after

The present invention relates to a method for recovering zinc from zinc-containing materials, especially from zinc-containing materials recovered from waste gases in metallurgical smelting processes. Particulate zinc-containing materials are agglomerated together with a carbonaceous reduction material and optionally slag forming materials, and are supplied to a gas tight closed electrothermic smelting furnace containing a molten bath kept at a temperature between 1200.degree. and 1700.degree. C. in which the agglomerates are smelted and subjected to selective reduction and volatilization of zinc and other volatile metals. An inert slag phase and optionally a liquid metal phase are tapped from the smelting furnace, and zinc and other volatile metals are recovered from the waste gas from the smelting furnace by condensation. In order to prevent reoxidation of metallic zinc the particulate zinc-containing materials are agglomerated together with a carbonaceous binder which cracks at a temperature below 700.degree. C. and forms carbon black, and that the temperature in the gas atmosphere in the smelting furnace is kept above 1000.degree. C. in order to maintain a volume ratio between CO.sub.2 and CO in the gas atmosphere in the smelting furnaces below 0.3.

Method for recovering zinc from zinc-containing waste materials

The present invention relates to a plasma torch intended for being submerged into a bath of molten metal, such as for example a steel melt. The torch comprises an outer electrode made from a non-consumable material and an inner electrode, where at least the outer electrode is made from a copper pipe having internal channels for circulation of a cooling medium, said copper pipe at least on the outside having a layer of refractory material. The layer of refractory material has a thickness between 1 and 5 mm and is made from Al.sub.2 O.sub.3 or from ZrO.sub.2 stabilized with 5-25% by weight of MgO and/or Y.sub.2 O.sub.3 or oxides of other rare earth elements.

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Oslo, Norway

Inger J Eikeland