Abstract: Described is a method for the production of ferrochromium and a rotary furnace employed in such method. Raw chromium ores, fluxes and carbonaceous reducing agent(s) are charged into a rotary furnace into which oxygen or oxygen-enriched air is blown to effect smelting reduction. Hot exhaust gases from the rotary reducing furnace are used for pre-heating and pre-reducing of the materials for saving the energy considerably as contrasted to conventional methods.

Abstract: The invention provides a process for refining steel comprising the steps of blowing a refining gas at the upper surface of the melt contained in a refining vessel by means of an overhead lance; injecting a stirring or processing gas directly into the vessel below the surface level of the melt therein; and introducing carbon from above onto or through the upper surface of the melt in the refining vessel.

Abstract: The present invention relates to a steelmaking process, in which the molten pig iron produced in a blast furnace is desiliconized, dephosphorized, decarburized and desulfurized. The characteristic of this invention is a sequence and combination of the refining steps. Namely, the steelmaking process of this invention has individual separate refining steps for realizing a removal reaction of the impurities. The objective reaction is the desiliconization in the first step, the dephosphorization in the second step, the decarburization in the third step and the desulfurization in the fourth step.

Abstract: A process for producing high chromium steel is disclosed which comprises supplying molten iron in a smelting furnace with a solid chromium source, carbonaceous powder and oxygen-containing gas in amounts so controlled as to keep the melt at a temperature in the range of less than 1650.degree. C. and above the minimum melt temperature at the specific carbon and chromium levels in the melt and which is capable of performing preferential decarbonization while inhibiting the oxidation of chromium.

Abstract: A process for the production of stainless steel in a top blown oxygen converter wherein the rate of carbon removal during the refining process is improved particularly from the standpoint of minimizing oxidation of other alloying elements such as chromium. This is achieved by introducing oxygen mixed with an inert gas through a tuyere and into the metal being refined either simultaneously during a portion of the oxygen blowing or after the completion of oxygen blowing but in any case it is continued until the required carbon level has been achieved, while the interior of the converter above the liquid level is maintained at subatmospheric pressure.

Abstract: A converter vessel is coaxially surrounded by a trunnion ring carried by a pair of trunnions for rotary or tilting motion about a horizontal axis. In order to permit rotation of the vessel relative to the trunnion ring about the vessel axis at right angles with the noted horizontal axis, two annular rows of support elements such as rollers are mounted on the trunnion ring and engaged with respective annular tires on the vessel so as to bear its radial load. Two other annular rows of rollers or like support elements are also mounted on the trunnion ring and engaged with the respective tires so as to bear the axial vessel load. Several identical drive mechanisms are compactly mounted within the trunnion ring for revolving the vessel through a gear drive, friction drive, or chain drive.

Abstract: In the top-and-bottom blown converter steel making process, a process is provided wherein the position of the bottom-blowing tuyeres is set such that the maximum X.sub.0 among the distances X between the respective tuyreres and the center of the converter bottom is up to 1.3 times the horizontal distance Y between the central vertical axis of the converter and the outermost boundary of a hot spot region developed on the molten iron surface by the top-blowing oxidizing gas from the lance. By setting the position of the bottom blowing tuyeres in this manner, the interference of the bottom-blowing gas with the top-blowing gas is promoted to enhance the agitation between the slag and the metal to reduce the concentration of iron value (T.Fe) in the slag, thereby improving the iron yield.

Abstract: The present invention relates to a procedure and an arrangement for spreading pulverized or granular additive material, preferably covering material, on the surface of a metal melt, preferably a steel melt, which is in an open metallurgical ladle by means of a spreading arrangement whereby at least a predetermined quantity of additive is made available in a dosing container whereby the dose is sub-divided into partial doses, the ladle is placed underneath the dosing container, the additive dose is made to fall under its own weight onto the surface of the metal melt and is spread out on the surface by means of a spreader which is connected to the dosing container.The arrangement for performing the procedure comprises a spreader (b 1) which consists of two or more concentrically-arranged truncated tubular cones (2), a dosing container (3), two valves (8), (9) for filling and emptying respectively the container (3).

Abstract: A method of using a rare earth and carbon dioxide to control the quality and quantity of graphite in cast iron.

Abstract: A method and a means for introducing close-grained carbonaceous fuels, which are suspended in a carrier gas, and oxygen into an iron melting bath are described.In this method the fuel and the oxygen can be alternately introduced through the same introduction passage of a tuyere into an iron melting bath below the surface of the bath.The means provides for alternate supply of fuel or oxygen and is regulated by means of the oxygen line pressure.

Abstract: The process for recovering metals of the 1.sup.st, 2.sup.nd, 4.sup.th, 5.sup.th, 6.sup.th, 7.sup.th and 8.sup.th sub-group of the periodic law from solutions of their salts, particularly from solutions containing hydrochloric acid contemplates as the first process step a neutralization (1) for precipitating the metals from their acid metal salt solutions in the form of hydroxides or carbonates. The precipitate is pressed (4), and via conduits (9, 10) finally divided metal of the metal having been present as a salt as well as a carbon source originating of waste materials, particularly in form of ground heat setting synthetic plastics materials such as phenolic resins, amine formaldehyde resins, epoxide resins, polyesters, and also CaCO.sub.3 is added. All components of this mixture must be used in a fine-grained state and preferably with a maximum particle size of 0.5 mm.

Abstract: A method for refining of steel melts for production of steel, especially stainless steel, with extremely low oxygen content is characterized in that a powdered non-oxidic earth alkali metal compound or alloy is injected by means of a non-oxidizing carrier gas, preferably an inert gas, into a well de-oxidized steel melt which is covered by a basic reduced slag in a metallurgical ladle, whereby at least a significant amount of the earth alkali metal is oxidized by the oxygen dissolved in the melt to form small particles of earth alkali metal oxide, of which some are separated out to the slag cover while the remaining portion of the earth alkali metals stays behind in the melt in elementary form or combined in the form of particulate earth alkali metal oxide in colloidal solution, and that then powdered earth alkali metal oxide is injected, whereby there latter, larger oxide particles function as nucleus forming agents for the continued reaction between earth alkali metals dissolved in the melt and oxygen, and a

Abstract: Liquid droplets in a freely falling stream are applied as a liquid reaction agent in the generation of a spatially-limited convective reaction system in such a way as that at least a portion of the droplets penetrate into the surface of the molten bath to interact with the molten metal.

Abstract: The device consists of a retractible tuyere which can be used with different types of steel melting furnaces, or any other metallurgical vessel. Said tuyere is introduced in the liquid steel bath to make the controlled refining of the same by means of gaseous oxygen injection with any other innert gas, generally argon.The retractible tuyere consists of two concentric pipes. Through the annular gap between the pipes a cooling gas or liquid fluid is injected, which is generally an hydrocarbon.Through the center pipe a refining gas mixture is injected. The system also consists of a cooled tuyere holding box and a fluid control and injection system.The tuyere is generally introduced through an opening made in the side wall of the furnace, in a way that the tip of the same is located below the liquid steel level. Due to the retractible characteristic of the tuyere, the same is introduced in the bath only during the time required by the process.

Abstract: The above invention concerns the use of sodium carbonate and various mixtures thereof in furnaces for converting iron while blowing with oxygen.This compound, suitably prepared and added to the converter with sufficient operator skill, permits one to take care of well known limitations of rapid conversion processes, notably increasing reactions removing elements which are not wanted in steel, in particular phosphorus and sulphur.After careful examination of all the aspects of the use of said materials in converters, those conditions have been identified which permit one to use with success this new method with sodium slags in all types of processing involving oxygen blowing.

Abstract: In a method of recovering heavy metals from filter residues containing metal oxides, metal hydroxides or metal carbonates, the residues are dried and reduced during heat supply in the presence of carbon-containing reducing agents. The metal-containing filter residues having a water content of 30 to 80% are dried in a three-compartment rotary drier (triplex drier), wherein a product having a grain size of 0.1 to 5 mm and a packing density of 0.4 to 1.2 kg/l results, which, after the addition of the carbon-containing reducing agents, is introduced into a crucible furnace at a filling height of 0.4 to 1.5 m. It is heated to a temperature above the melting point of the metal to be recovered. The filling height is kept approximately constant during the volume reduction of the material to be reduced occurring at an increased temperature by refilling the batch.

Abstract: In the operation of a top-and-bottom blown converter, top-blowing oxygen gas is blown such that the center of a hot spot created by the oxygen gas jet from each of the nozzles of a top-blowing multi-nozzle lance is positioned outside a bubbling region of the molten metal surface which rising bubbles of gas from bottom-blowing tuyeres reach.

Abstract: The invention concerns an electro-metal smelting furnace with at least one taphole located at the bottom with which hole is associated a closure equipped with a drive.

Abstract: A process for protecting oxygen injection nozzles and the surrounding refractory lining of a molten metal refining vessel having such oxygen injection nozzles beneath the bath surface. The injection nozzle comprises at least three concentric pipes, the central conduit thereof being connected to a source of oxygen, the outer annular conduits thereof each being supplied with a protective fluid, said protective fluid containing at least one hydroxyl compound or water or a mixture thereof. The protective hydroxyl compounds are selected from the gaseous or liquid alcohol group and preferably from the aliphatic alcohol group. Methanol, ethanol, propanol and butanol are preferred alcohols.Apparatus for carrying out the process is also disclosed.

Abstract: Cast iron having more regular and uniform free graphite particle shape and distribution is more reliably produced by using pre-reduced iron pellets as a major component of the melting stock. Cast iron made in this way may be advantageously used to form ingot molds, brake discs, and other products.