Abstract: The invention relates to a method and means for cooling lump material in which the material in a vertical, gas-tight cooler (1) is subjected in a furst step to a transverse cooling flow (at 9) and in a second step to counter-flow cooling (at 20). Optimal cooling effect is obtained by a distribution of the cooling gas between transverse and counter-flow cooling in such a way that maximum temperature is obtained in the cooling gas leaving through the outlet (13).

Abstract: In a method for supplying thermal energy by means of a plasma arc heater to a reactor filled with solid, lump reduction material, the thermal energy is supplied via an outer or transferred arc, one electrode of which is formed by the heater and the other electrode of which is formed by the reduction material in the reactor.

Abstract: Finely powdered oxidde ore is introduced (at 17) in a reactor (11), possibly together with slag-formers, and treated in three zones in the reactor. The material is preheated and possibly melted in an upper, oxidizing zone by the combustion of carbon monoxide and hydrogen gas from the middle zone below with a gas containing oxygen. In a middle zone consisting of a slag bath, the preheated and possibly melted oxide material at least partially reduced by the simultaneous injection of carbonaceous material and/or material containing hydrocarbon (15, 16) and thermal energy supplied primarily by means of gas heated in a plasma generator (14). Finally, the material is caused to sink into a lower zone at the bottom of the reactor, from where it is tapped intermittently, together with the slag, through a tapping aperture (19).

Abstract: The invention relates to the recovery of chemicals from waste liquor from wood pulp process, primarily black liquor, while utilizing energy liberated. Controlled total vaporization of the pulp waste liquor at high temperature and low oxygen potential is achieved by the external supply of energy. During the subsequent condensation and separation a melt or water solution is obtained which, without causticizing, can be used for the preparation of white liquor, and also an energy rich gas and mainly free from sulphur, consisting primarily of carbon monoxide and hydrogen.

Abstract: A method and an apparatus are disclosed for heating process air for industrial purposes to a predetermined temperature. In one embodiment, the method comprises passing a first air-flow portion through a plasma generator and thus heating said portion to a temperature sufficiently high to cause the ionization of nitrogen and oxygen in the portion and thus form a plasma gas, immediately thereafter adding to said plasma gas a material containing carbon and/or hydrocarbon in sufficient quantity that when said material is reacted with the plasma gas, the ratio CO+H.sub.2 /CO.sub.2 +H.sub.2 O is at least 0.1 thereby substantially avoiding the formation of nitrogen oxide; and immediately thereafter mixing with the plasma gas, with its content of material containing carbon and/or hydrocarbon, a second air flow in such proportion that the predetermined temperature is achieved in the final air mixture.

Abstract: Recovery of zinc from a gas containing zinc vapor is carried out by means of lead circulating in a circuit and separating out pure metallic zinc by cooling said lead. The gas containing zinc vapor is brought into intimate contact with atomized lead in liquid form which takes up the zinc. The lead is introduced at the top of a cooling tower (1) and the gas is conducted in counter-flow to the atomized lead droplets. Lead collected at the bottom of the tower (1) is transported (7) to a separating chamber (8) where it is cooled, so that the zinc is segregated from the lead and can be separated (10). The lead is then cooled further before being recirculated (15, 16) to the top of the cooling tower.

Abstract: The invention relates to a means for electrically heating gases, comprising cylindrical electrodes (2,3) between which an electric arc (20) is generated. Between these two electrodes are arranged one or more spacers (6,7) whose length is from 100 to 500 mm.

Abstract: Ferrosilicon is manufactured from a material containing silica and a raw material containing iron by injecting these materials, possibly together with a reducing agent, with the help of a carrier gas into a plasma gas. The silica and the iron raw material, possibly with the reducing agent, heated in this way are then introduced with the energy-rich plasma gas into a reaction chamber surrounded by a solid reducing agent in lump form, the silica thus being brought to the molten state, being reduced and reacting with the iron to form ferrosilicon.

Abstract: The invention relates to a method and plant for converting waste material containing and/or comprising thermally disintegratable chemical substances to stable final products such as CO.sub.2, H.sub.2 O and HCl, the waste material being subjected to a plasma gas of high temperature generated in a plasma generator in order to effect disintegration.The waste material in feedable form is caused to flow through a reaction zone, heated by a plasma gas to at least 2000.degree. C. The reaction zone comprises a cavity burned in a gas-permeable filling in piece form arranged in a reaction chamber, by means of the plasma jet from the plasma generator directed towards and projecting into said filling. An appropriate oxygen potential is maintained in at least the reaction zone such that the disintegration products are continuously converted to stable final products.

Abstract: A gas mixture obtained from reduction of material containing zinc oxide in a furnace, is cleaned from accompanying vapor of metals or compounds having a boiling point higher than zinc and from accompanying dust particles by cooling the hot gas mixture to almost the saturation temperature of zinc vapor by the introduction therein of solid or liquid metal.

Abstract: A method of reducing and recovering volatile metal from metal oxides comprising the steps of injecting metal oxide-containing material into a shaft reactor, simultaneously injecting reducing agent into said reactor, continuously maintaining said reactor substantially filled with coke, supplying thermal energy to the reactor, preferably by means of a plasma burner, such that at least some of the metal oxides are reduced to metal and melted or volatilized depending upon whether the metal is volatile. The melted metal is removed from the bottom of the reactor while the volatilized metal is permitted to flow upwardly through the shaft reactor in the form of metal vapor together with a gas flow. The coke in the shaft reactor through which the volatilized metal passes is maintained at a temperature in excess of 1000.degree. C., thus screening the upper portion of the shaft reactor and the reactor top by means of the coke so as to prevent condensation of the volatilized metal.

Abstract: In a process for manufacturing a gas substantially containing carbon monoxide and hydrogen gas from a starting material containing carbon and/or hydrocarbon, the starting material is injected in powder or liquid form together with an oxidizing agent and slag former in a combustion zone while heat energy is simultaneously supplied. The combustion zone is formed in the lower portion of a shaft filled with particulate, solid, carbonaceous material and sulphur-binding slag former.

Abstract: In a method of utilizing a plasma generator to increase the blast temperature in a shaft furnace for melting and possible reduction of metals and/or metal oxides, the thermal energy produced in the plasma generator is transferred, in order essentially to prevent the formation of nitrogen oxide, from the plasma generator to the blast gas via a gas which is inert or oxidizing in relation to the metal to be processed, the product of the oxygen mol fraction and the nitrogen mol fraction in the gas used being less than or equal to 0.02.

Abstract: Silicon is manufactured from powdered material containing silica by injecting this, optionally together with a reducing agent, into a gas plasma with the help of a carrier gas. Thereafter the silica material thus heated, together with the reducing agent if any and the energy-rich plasma gas, is introduced in a reaction chamber surrounded by solid reducing agent in lump form, so that the silica is caused to melt and is reduced to liquid silicon.

Abstract: Energy consumption may be minimized when reducing iron oxide with reducing gases which are at least partially re-circulated in the process and where the re-circulation gas is washed to remove the reaction product CO.sub.2 in what is known as a CO.sub.2 wash to enable it to be re-used, by the heat requirement necessary for regenerating the washing liquid in the CO.sub.2 wash being entirely or partially covered by the physical heat content in top gas from the shaft furnace and/or gas leaving the sponge-iron cooler of the shaft furnace.

Abstract: Disclosed are a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft utilizing recirculation gases. Reaction gas is removed from the shaft furnace, substantially cleaned of all CO.sub.2 and H.sub.2 O, and then divided into at least two flow portions one of which is passed to a gas generator comprising a plasma burner. A reducing agent such as pit coal is injected together with an oxidant into the hot gas from the plasma burner so as to form a gas mixture comprised primarily of CO and H.sub.2, which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace.

Abstract: Disclosed are a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft utilizing recirculation gases. Reaction gas is removed from the shaft furnace, substantially cleaned of all CO.sub.2 and H.sub.2 O, and then divided into at least two flow portions one of which is passed to a gas generator comprising a gas generating shaft substantially filled with a solid reducing agent and a plasma burner arranged in the lower portion of said shaft. An oxidant is injected into the hot gas from the plasma burner so as to form a gas mixture comprised primarily of CO and H.sub.2, which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace.

Abstract: A method of manufacturing stainless steel comprising the steps of injecting a starting material containing chromium oxide and iron oxide into the lower portion of a reactor, said reactor containing a solid reducing agent, passing said starting material into a reduction zone within said lower portion, said reduction zone being maintained by the use of a plasma generator adjacent thereto, substantially instantaneously reducing and melting said starting material in said reduction zone, and removing the melted and reduced chromiferous product from the bottom of the reactor. The chromiferous product may then be further refined in an AOD convertor or the like.

Abstract: A method of recovering non-volatile metals from materials in dust form containing metal oxides, comprising the steps of blowing the material into the lower portion of a reactor, said reactor containing a solid reducing agent, passing said starting material into a reduction zone within said lower portion, said reduction zone being maintained by the use of a plasma generator adjacent thereto, substantially instantaneously reducing and melting said starting material in sad reduction zone, and removing the melted and reduced metal product from the bottom of the reactor.

Abstract: A method and apparatus for increasing blast gas temperature in a shaft furnace by passing at least part of the blast gas through a plasma burner, and also supplying additional fuel to the furnace at the tuyere level.