Abstract: A process of treating complex sulfide concentrate includes the steps of roasting wet or slurried complex sulfide concentrate in a furnace at a temperature of at least 720° C. to obtain a calcine; smelting the calcine under inert or oxygen free atmosphere in a smelting furnace to obtain a matte, and optionally granulating the matte to obtain a granulated matte.

Abstract: A process of treating complex sulfide concentrate includes the steps of roasting wet or slurried complex sulfide concentrate in a furnace at a temperature of at least 720° C. to obtain a calcine; smelting the calcine under inert or oxygen free atmosphere in a smelting furnace to obtain a matte, and optionally granulating the matte to obtain a granulated matte.

Abstract: A method for processing slags containing iron and non-ferrous metals, to produce clean slag free of detrimental substances and non-ferrous metals and suitable for use as a raw material or construction material. Slag is reduced in a reduction furnace with the help of reducing agents so that at least 5% of the iron of the slag is reduced into metal. Some of the non-ferrous metals, such as zinc, lead, arsenic and cadmium, vaporize. The contents of the reduction furnace are continuously mixed to prevent separation of a metallic phase from the slag. The generated slag-metal mixture is tapped off from the reduction furnace, cooled, crushed and ground to a finer size. Finally, a metal fraction is separated from a clean slag.

Abstract: The invention relates to a method for thermally processing ?-spodumene, i.e. lithium aluminum silicate, by which treatment it is transformed into ?-spodumene, which is more advantageous for further processing; in the method, concentrate or ore with a grain size of 20-1,000 ?m is processed in a fluidized bed reactor, at a temperature of 800-1,000° C., by using an oxygenous gas as the fluidizing gas.

Abstract: The invention relates to a method for processing slags of non-ferrous metallurgy, containing iron and valuable metals, to produce clean slag that is free of detrimental substances and valuable metals and suitable as it is for use as a raw material or construction material. Slag is reduced in a reduction furnace (18) with the help of reducing agents (19) so far that at least 5% of the iron of the slag is reduced into metal. At the same time, some of the valuable metals, such as zinc, lead, arsenic and cadmium, vaporize. The contents of the reduction furnace (18) are continuously mixed to prevent separation of a metallic phase from the slag. The generated slag-metal mixture (21) is tapped off from the reduction furnace (18), cooled, crushed and ground to a finer size. Finally, a metal fraction (26) is separated from a clean slag (25).

Abstract: The invention relates to a method for thermally processing ?-spodumene, i.e. lithium aluminum silicate, by which treatment it is transformed into ?-spodumene, which is more advantageous for further processing; in the method, concentrate or ore with a grain size of 20-1,000 ?m is processed in a fluidized bed reactor, at a temperature of 800-1,000° C., by using an oxygenous gas as the fluidizing gas.

Abstract: The present invention relates to method, which helps to reduce and remove the build-up forming on the grate of a fluidized-bed furnace in the roasting of fine-grained material such as concentrate. The concentrate is fed into the roaster from the wall of the furnace, and oxygen-containing gas is fed via gas nozzles under the grate in the bottom of the furnace in order to fluidize the concentrate and oxidize it during fluidization. Below the concentrate feed point, or feed grate, the oxygen content of the gas to be fed is raised compared with the oxygen content of the gas fed elsewhere.

Abstract: This invention relates to a method for stabilizing a fluidized bed used in roasting by adjusting the oxygen content of the roasting gas in the bed. The fine-grained material for roasting is fed into the furnace above the fluidized bed and the roasting gas, which causes the fluidizing, is fed into the bottom of the furnace through a grate. In this method, the total amount of oxygen in the roasting gas to be fed and the average total oxygen requirement of the material to be roasted are calculated and the ratio between them regulated so that the oxygen coefficient in the bed is over 1.

Abstract: The present invention relates to method, which helps to reduce and remove the build-up forming on the grate of a fluidized-bed furnace in the roasting of fine-grained material such as concentrate. The concentrate is fed into the roaster from the wall of the furnace, and oxygen-containing gas is fed via gas nozzles under the grate in the bottom of the furnace in order to fluidize the concentrate and oxidize it during fluidization. Below the concentrate feed point, or feed grate, the oxygen content of the gas to be fed is raised compared with the oxygen content of the gas fed elsewhere.

Abstract: This invention relates to a method for stabilizing a fluidized bed used in roasting by adjusting the oxygen content of the roasting gas in the bed. The fine-grained material for roasting is fed into the furnace above the fluidized bed and the roasting gas, which causes the fluidizing, is fed into the bottom of the furnace through a grate. In this method, the total amount of oxygen in the roasting gas to be fed and the average total oxygen requirement of the material to be roasted are calculated and the ratio between them regulated so that the oxygen coefficient in the bed is over 1.

Abstract: The invention relates to a method for utilizing zinciferous waste from metal smelters, such as steel smelters, so that the transmission of fluorides to the highly zinciferous secondary dusts is prevented during the treatment of the gas obtained from the waste smelting furnace. Fluorides are extremely harmful for the zinc process, and therefore it is important to prevent them from entering the process. By adjusting, according to the invention, the temperature and composition of the exhaust gases created in the smelting treatment of zinciferous dusts and other waste, the fluorides and the highly zinciferous fraction are obtained in different end products. Other valuable metals are recovered from the metal layer created on the bottom of the furnace.

Abstract: The invention relates to a method for removing sulphur and nitrogen compounds from gases by means of long-chained sulphur compounds mainly in acidic conditions, with an electroconductive solid material serving as the carrier of the long-chained sulphur compounds. The properties of the solid material surface are adjusted to be favourable to the sulphur polymer by means of potential measurements with mineral electrodes.

Abstract: The invention relates to a method for cleaning exhaust gases weak in sulphur dioxide, or sulphur dioxide and hydrogen sulphide. In order to remove the sulphur content of an exhaust gas, the exhaust gas is absorbed into a solution containing sulphide. Thereafter into the solution is added an agent which causes any unstable compounds of sulphur and oxygen, such as thiosulphate and polythionates, which are formed in the scrubbing solution, to decompose into elemental sulphur and sulphate in the autoclave whereinto the scrubbing solution is fed. The pH of the solution emerging from the autoclave is adjusted to stay within the range 2.0-2.9.

Abstract: Coke or activated carbon is produced from a moist organic substance, for example from a residue from the production of furfural. Initially the moist organic substance is introduced together with hot flue gases into a drying zone of a cylinder furnace and the organic substance is mixed with the hot gases and dried according to the co-current principle. Subsequent thereto the dried substance and the gases are directed into a coking zone of the same furnace, an oxygen-bearing gas also being introduced into said coking zone and the volatile constituents of the organic substance being reduction burned according to the co-current principle so as to produce a coked product. When coke is to be produced, said coked product is withdrawn together with gases from the trailing end of the furnace and the gases are separated therefrom.