Abstract: To produce molten pig iron by melt-reduction of iron ores of various grain sizes containing a fraction A including grain sizes to which diameters of less than 0.2 mm correspond, by pre-reducing the ore by reducing gas, completely reducing the pre-reduced material and smelting it to molten pig iron in a melter gasifier, the pre-reduced ore fraction A is separated from a fraction B including larger grain-size particles by classification by means of reducing-gas and the two fractions A and B are completely reduced separately and fed to the melting zone of the melter gasifier.

Abstract: There is disclosed a process of dezincifying the flow of material at the operation of a plant for the production of pig iron including a direct reduction shaft furnace and a meltdown gasifier.The crude reducing gas drawn off the meltdown gasifier is dedusted in two steps. In the first step zinc-poor coal dust is separated in a cyclone operated at a higher temperature, which is recycled into the meltdown gasifier. In the second step, upon cooling of the gas leaving the first cyclone, solid particles enriched with zinc are separated at a lower temperature. The dezincified reducing gas is fed to the direct reduction shaft furnace and the zinc-rich substances separated off the second cyclones are processed to a zinc concentrate.

Abstract: To gain electric energy in addition to producing molten pig iron, from lumpy iron ore and solid fuels, by using a direct reduction zone for the reduction of the iron ore to sponge iron and a meltdown-gasifying zone for the production of molten pig iron, carbon carriers are used in, and oxygen-containing gases are supplied to, the meltdown-gasifying zone. The reduction gas forming is fed into the direct reduction zone. The reduction gas reacted there is supplied as top gas to a power generation plant including a turbine. In order to adapt the power generation to the power consumption by simultaneously avoiding any influence on the metallurgical conditions at the production of pig iron and its further processing, the charge of carbon carriers into the meltdown-gasifying zone is varied as a function of the gas consumption of the power generation plant in a manner that, with a higher gas consumption, the volatile constituents of the charge are increased and the C.sub.

Abstract: A process and an arrangement for the production of molten pig iron or steel pre-products from particulate ferrous material as well as for the production of reducing gas in a meltdown gasifier. A fluidized bed of coke particles is formed by the addition of coal and the injection of oxygen-containing gas. In order to ensure a satisfactory mode of operation of the meltdown gasifier even if coal of inferior quality with a high moisture content and a high portion of volatile matter is used, additional heat is supplied to the meltdown gasifier above the feed lines for the fluidized-bed-forming oxygen-containing gas by burning and/or degassing coal particles separated from the reducing gas.

Abstract: In a method of producing a mixed gas from a process gas of a continuously working gasifier and a discontinuously incurred off-gas of an oxygen blowing converter, the off-gas of the refining process having the lower pressure is sucked into the process gas of the gasifier with the higher pressure via a gas jet ejector. The process gas serves as power gas, and subsequently the mixed gas is dedusted. A plant for producing steel includes a plant for recovering pig iron formed by a reduction shaft furnace and a melt-down gasifier, and at least one oxygen blowing converter for converting the pig iron into steel. The reduction shaft furnace has a process or top gas duct system, the converter has a converter off-gas duct, and an ejector connects both, the converter off-gas thus being feedable into the top gas duct system to form the mixed gas. Common dedusting and washing devices are provided for the mixed gas and safety devices for preventing oxygen from entering into the mixed gas.

Abstract: In the smelting process of recovering metal from non-ferrous metal oxide ores or concentrates and/or from fine-grained non-ferrous metal sulfide ores or concentrates, particularly from non-ferrous heavy metal sulfide ores or concentrates, any sulfide ores are initially oxidized. The ores or concentrates are then supplied to a fluidized bed of coal in a melting gasifier (1). A certain particle size is maintained. Sulfide ores are supplied to a melting burner (2), which directs a flame jet into the fluidized bed of coal (FIG. 1).

Abstract: A process and an arrangement for the production of molten pig iron or steel pre-products from particulate ferrous material as well as for the production of reducing gas in a meltdown gasifier. A fluidized bed of coke particles is formed by the addition of coal and the injection of oxygen-containing gas. In order to ensure a satisfactory mode of operation of the meltdown gasifier even if coal of inferior quality with a high moisture content and a high portion of volatile matter is used, additional heat is supplied to the meltdown gasifier above the feed lines for the fluidized-bed-forming oxygen-containing gas by burning and/or degassing coal particles separated from the reducing gas.

Abstract: There is disclosed a process for the production of molten pig iron or of steel pre-products from particulate ferrous material as well as for the production of reduction gas in a meltdown gasifier. A fluidized-bed zone is formed by coke particles upon the addition of coal and by blowing in oxygen-containing gas by nozzle pipes penetrating the wall of the meltdown gasifier. The ferrous material to be reduced is introduced into the fluidized bed. In order to be able to produce molten pig iron and liquid steel pre-products in a direct reduction process with a lower sulfur content than has hitherto been the case, without having to make any particular demands on the sulfur content of the coal used, the ferrous material to be reduced is supplied closely above the blow-in gas nozzle plane producing the fluidized bed.

Abstract: In a method of producing molten pig iron or steel pre-products from particulate ferrous material, as well as of producing reduction gas in a melt-down gasifier by adding coal and by blowing in oxygen-containing gas by means of nozzle pipes penetrating the wall of the melt-down gasifier, a fixed bed formed of coke particles, through which the oxygen-containing gas flows and a superposed fluidized bed of coke particles are formed, and the ferrous material is charged onto the fluidized bed. Below the fixed bed through which oxygen-containing gas flows, a fixed bed of coke particles not passed through by gas is provided, and the fluidized bed above the fixed bed passed through by oxygen-containing gas is passed through by a gas free from oxygen or having a low oxygen content.

Abstract: In a method of producing a mixed gas from a process gas of a continuously working gasifier and a discontinuously incurred off-gas of an oxygen blowing converter, the off-gas of the refining process having the lower pressure is sucked into the process gas of the gasifier with the higher pressure via a gas jet ejector. The process gas serves as power gas, and subsequently the mixed gas is dedusted. A plant for producing steel includes a plant for recoverng pig iron formed by a reduction shaft furnace and a melt-down gasifier, and at least one oxygen blowing converter for converting the pig iron into steel. The reduction shaft furnace has a process or top gas duct system, the converter has a converter off-gas duct, and an ejector connects both, the converter off-gas thus being feedable into the top gas duct system to form the mixed gas. Common dedusting and washing devices are provided for the mixed gas and safety devices for preventing oxygen from entering into the mixed gas.

Abstract: There is disclosed a method and a melt-down gasifier for producing molten pig iron or steel pre-products and reduction gas. A first fluidized-bed zone is formed by coke particles, with a heavy motion of the particles, above a first blow-in plane by the addition of coal and by blowing in oxygen-containing gas. Iron sponge particles and/or pre-reduced iron ore particles with a substantial portion of particle sizes of more than 3 mm are added to the first fluidized-bed zone from above. A melt-down gasifier for carrying out the method is formed by a refractorily lined vessel having openings for the addition of coal and ferrous material, openings for the emergence of the reduction gases produced, and openings for tapping the metal melt and the slag. Pipes or nozzles enter into the meltdown gasifier above the slag level at at least two different heights.

Abstract: A process for drying and/or calcining bulk material in a rotary kiln when hot gases are passed countercurrent to the flow of bulk material thereto, and the bulk material is dried and/or calcined in the rotary kiln is disclosed. According to the invention, the bulk material is dried and/or calcined, as it passes from the feed end of the rotary kiln to the discharge end thereof, by contacting the same with hot gases and thereafter, as the bulk material passes towards the discharge end of the rotary kiln, the bulk material is heated by indirect heat exchange with such hot gases. An apparatus for carrying out such process is also disclosed. The apparatus is a rotary kiln equipped with a centrally disposed tube, disposed axially within the rotary kiln toward the bulk material discharge end of the rotary kiln whereby an annular space is defined between the outer wall of the central tube and inner wall of the rotary kiln.

Abstract: An improved process for the preparation of crystalline cryolite having a molar ratio Na:Al of 2.9:1 to 3.0:1, by reacting aqueous solutions of aluminum fluoride with at least a stoichiometric amount of sodium fluoride in aqueous solution, while heating, in the presence of cryolite seed crystals, wherein the sodium fluoride is used in an amount of 3.2 to 3.5 moles of sodium per mole of aluminum, the aluminum fluoride concentration being from 15 to 250 g./l., the sodium fluoride concentration being from 30 to 42 g./l., the reaction temperature being from 85.degree. to 100.degree. C., the reaction time from 0.5 to 3 hours and the pH value in the reaction mixture from 5 to 8, to provide an end product having an adsorbed water content of 8% or less.