Abstract: High-strength pipes are manufactured from cold-deformed carbon steel or alloyed steel for use in acid environment, in which the H.sub.2 S partial pressure in gaseous phase may exceed 300 Pa or in which the H.sub.2 S content in liquid phase may have a corresponding equilibrium pressure and/or in which CO.sub.2 and other acidifying substances may be present. The weight % composition of the steel is preferably:C 0-1.20%Si 0-1.0%Mn 0-3.0%Cr 0-2.0%Ni 0-1.0%Mo 0-1.0%Cu 0-1.0%V 0-0.3%Nb 0-0.2%Ca 0-0.05%Fe+incidental ingredients and impurities up to 100%.

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: Wear and slip resistant floors are described comprising a suitable substrate and a surface layer comprising a synthetic resin, preferably polyester, as the matrix and containing uniformly distributed therein a mixed waste material derived from a steel grinding operation and being composed of from about 60 to about 85% by weight of coarse metallic particles having a particle size from about 0.2 mm to about 1 mm with a mean particle size of about 0.5 mm and fine primarily oxidic particles, having a particle size from very fine up to about 0.2 mm, with a mean particle size of about 0.07 mm. The surface layer may also contain fiber glass reinforcement and other additives.

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: In a method of manufacturing aluminium-silicon alloy from natural mineral containing alumina and silica and carbon powder, the natural mineral in powder form is injected together with a reducing agent in the form of a carbon carrier, with the aid of a carrier gas into a plasma gas produced in a plasma generator. The mineral thus heated is then introduced, together with the reducing agent and the energy-rich plasma gas, into a reaction chamber surrounded substantially on all sides by solid reducing agent in lump form. Examples of the natural mineral include andalusite, cyanite, silimite, nepheline, quartz, clay containing alumina, such as bauxite, and mixtures of two or more of these minerals.

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: Pure ferro-alloy metals are isolated from fine-grained crude oxidic mineral products by reduction melting and subsequent anodic liberation of the iron. The reduction melting is performed in a plasma-heated furnace into which the fine-grained oxide material is blown together with carbon powder and circulating exhaust gas, extremely over-heated in a plasma generator, the quantity of carbon powder being dosed so that most of the alloy metal(s) is converted to carbides during the reduction. After electrolysis, the anode residue will consist primarily of alloy metal carbides from which the metal can be recovered by known methods.

Abstract: A method for producing fine-grain iron-containing metal oxide material, the method comprising a first reduction stage wherein the oxide material is at least partially reduced in a fluidized state at a temperature of approximately 1025.degree.-1275.degree. K. by a reducing gas which is carbon monoxide or carbon monoxide mixed with hydrogen, followed by a smelting and final reduction stage to form a metal melt, the reducing gas used for the first reduction stage obtained from the smelting and final reduction stage. Prior to the first reduction stage, relatively large cakes or shaped pieces are formed from the fine-grain metal-oxide material in the presence of moisture and a hydraulic binder and the cakes or pieces caused to harden.