Abstract: A method for oxidizing treatment of molten matte and at the same time directly smelting sulphidic concentrate in a refractory-lined liquid bath reactor, e.g. a converter, into which oxidizing air is introduced below the surface of the liquid bath. For additional supply of energy in order to achieve thermal balance or increase of capacity, sulphidic concentrate is introduced into the gas phase of the liquid bath reactor together with oxygen gas or oxygen-enriched gas by means of a concentrate burner.

Abstract: A method of reducing material containing metal oxide in a circulating fluidized bed, in which coal in excess and air is introduced into the fluidization chamber so as to maintain a temperature of >850.degree. C. in the chamber. Bed material which has been separated from the flue gases is conveyed through a carbidization chamber in a recirculation system at a temperature of <850.degree. C. to the lower part of the fluidization chamber. Conditions favorable for formation of carbide are maintained in the carbidization chamber.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a process for the refining of sulfidic concentrates which contain arsenic, antimony and bismuth, wherein a suspension of the sulfidic concentrate and oxygen or oxygen-enriched air is introduced into the upper part of a reaction zone, in the lower part of which the direction of the gases is deflected sidewards in order to cause the molten and solid particles traveling along with the gases to impinge against the surface of the melt below the reaction zone. In order to form a molten or semi-solid phase, concentrate, oxygen or oxygen-enriched air, and a carbon- or sulfur-containing fuel are introduced into the reaction zone in such proportions that in the upper part of the reaction zone there is formed an atmosphere containing sulfur and sulfur dioxide and having a temperture above 900.degree. C. and a maximum oxygen pressure of 10.sup.-6 atm in order to volatilize the arsenic, antimony and bismuth, and possibly the lead and zinc.