Abstract: A process for the removal of impurities from sulphidic and metallized molten copper mattes, in which in preliminary smelting of the crude metal molten sulphide and molten arsenide-antimonide phases are produced, whereby (a) the molten arsenide-antimonide matte is treated with elemental sulphur vapor to produce molten sulphide and molten arsenide phases in equilibrium with each other, that after this the conjugate melt system is sulphurated continuously under reduced pressure in order to volatilize arsenic, antimony, bismuth, lead and tin, or (b) the conjugate molten phases in equilibrium with each other are separated from each other, the thus separated arsenide matte is sulphurated further in a solid state and advantageously using elemental sulphur vapor at high partial pressure in order to volatilize arsenic, antimony, bismuth, selenium and tellurium from the matte as sulphides, and the separated molten sulphide phase is sulphurated under reduced pressure to volatilize arsenic, antimony, bismuth, lead and ti

Abstract: A method of producing steel from ferrous hot metal containing carbon includes the steps of delivering oxygen and a surrounding sheath of hydrocarbon shielding fluid to the metal and beneath its surface to elevate the temperature to at least 1350.degree. C. Iron material taken from the group consisting of prereduced iron ore, prereduced iron pellets and iron ore or combinations thereof are then delivered to the metal at controlled rates. The rate of charging is balanced with the heat input to the bath, in order to maintain or increase the bath temperature. The heat input is supplied by the simultaneous injection of carbon and oxygen through bottom tuyeres. The rate of carbon injection is also regulated to maintain the carbon content in the bath at the desired level.

Abstract: A method of producing molten iron in which iron oxide is fed together with carbon to an oxygen-top-blown melt from below through blocks whose pores permit the particles to be entrained into the melt in a carrier gas, the pores preventing penetration of the molten metal.

Abstract: A flux for overlay welding, essentially containing by weight 30-70% of CaF.sub.2, 10-30% of Al.sub.2 O.sub.3, 1-15% of CaO, 5-25% of SiO.sub.2 and 5-25% of MgO such that the total amount of CaF.sub.2, Al.sub.2 O.sub.3, CaO, SiO.sub.2 and MgO is greater than 70%, while satisfying the conditions of MgO/(Al.sub.2 O.sub.3 +SiO.sub.2).gtoreq.0.20, MgO/SiO.sub.2 .ltoreq.2.0 and MgO/Al.sub.2 O.sub.3 .ltoreq.2.0.

Abstract: This invention discloses a method for covering the surface of a molten metal to preserve the heat of the molten metal and to prevent oxidation of the molten metal by the surrounding atmosphere, comprising covering the surface of the molten metal with as many floating elements of a molten metal surface covering material as can be floated on the surface of the molten metal. Also disclosed is the molten metal surface covering material itself, which comprises a plurality of suitably shaped floating elements made of an inorganic refractory material, which may comprise a calcium silicate hydrate in matrix form, such as xonotlite, and may include fibrous wollastonite, or it may comprise ceramic fibers bound with an inorganic binding agent. Typically, the floating elements are substantially spherical with a diameter of 10 to 100 mm, and their density is 0.7 to 1.4 g/cm.sup.3.

Abstract: A system for evacuating gases from a top blown steel making converter measures any actual value pressure in a chamber between the seal of a closure ring and duct on which this ring is mounted for movement toward and away from the converter mouth, thereby preventing perturbations from affecting the measurements and allowing accurate control of the evacuating blower to balance the rate of evacuation of the gases and the rate evolution therein in the converter at least during a portion of the blow.

Abstract: A method of and an apparatus for heating, melting and production of gaseous fuel include supplying air, coal, steam into a melt. The melt contains elements readily oxidized by air. These elements produce oxides readily reduced by carbon. The overall results of the reactions of elements oxidation and reduction consist in the production of CO containing gas and evolving heat. The heat evolved is extracted from the melt by submergence of solid to be heated into the melt, by injection of heated gases into molten slag, by heat exchange between the wall confining the melt and gas, liquid or solid to be heated, or by conversion of steam into H.sub.2 and CO.

Abstract: A system for treating, normally refining, a metallurgical melt has a melt-containing vessel having below the level of the melt an at least gas-pervious wall portion. A finely divided treatment solids is suspended in a treatment gas and this suspension is introduced through the pervious wall portion into the melt and reacting the melt with the gas and solids. The wall portion has openings oriented so that the gases and particles can pass into the vessel through them, but the molten metal therein cannot enter them. A plurality of such gas-and particle-pervious inserts are provided in the base of the crucible. They can be individually controlled relative to respective sensors provided above the melt. Thus exothermically reacting gases and/or particles are fed in under cold spots, or endothermically reacting gases and/or particles are fed in under hot spots.

Abstract: Solder flux compositions are prepared by forming a dispersion of a flux material in a liquid in which the flux is substantially insoluble. The composition may be applied to a workpiece by brushing, spraying, or as an unstable foam. A method of tinning circuit boards using such flux compositions is also described.

Abstract: A granular flux is made by intimately mixing a particulate glass frit with carbon black. The glass frit typically employed has a particle size distribution such that substantially all of the frit material has a particle size within the range of 0.5 to 4 mm. The carbon black is included in the flux in an amount of from 1 to 10 wt. %, based on the amount of the frit used. The disclosed flux is characterized by good flowability and its ability to remain mixed during transport.

Abstract: In order to produce metals or ferroalloys, a mixture of metal oxides, reducing agents and possibly iron is ignited, to produce a metal melt as well as a slag melt. After the burn-out the still liquid slag is reacted with a suitable means, preferably calcium fluoride to increase its electrical conductivity. The liquid slag is then heated and simultaneously ignited by alternating current applied to water-cooled graphite electrodes. Over an emperically determined time span, the melt is reacted with an additional reducing agent, until substantially complete transformation of the metal oxide remaining in the slag and migration of the resulting metal into the metal phase.

Abstract: In a top-and-bottom blown converter having a plurality of tuyeres arranged at the bottom of converter housing, a monitoring sub-lance is vertically movable within a region defined beween vertical planes passing through parallel lines horizontally spaced a distance of 300 mm from a tuyere aligning line.

Abstract: A blowing tuyere to be embedded in a bottom of side wall of a molten metal bath container for blowing a gas thereinto, the tuyere including a cylindrical core body fixedly located at the center of the tuyere and an outer tube fixed concentrically around the core body with a gap of a predetermined width to form an annular blowing passage therebetween.

Abstract: The impurities of molten pig iron produced by a blast furnace are removed exclusively in a converter, according to the conventional steelmaking refining method.The desulfurization and dephosphorization, which have been conventionally achieved in a converter, are replaced by the desulfurization and dephosphorization during the pretreatment of the molten pig iron, according to recently developed steelmaking methods. In the multi-step steelmaking refining method, such oxygen-blowing as that employed for the conventional converter would result in a rather violent spitting and reduction in recovery of iron.It is an object of the present invention to provide a multi-phase steelmaking refining method, in which decarburization is carried out without causing the disadvantages in the prior art.

Abstract: A melt is contained in a vessel having below the level of the melt an at least gas-pervious wall portion. First the slag is removed, normally by pouring it off, from the melt. Then a finely divided treatment solids suspended in a gas is introduced through the wall portion into the melt. The melt reacts thoroughly with these solids. Immediately deslagging the melt substantially reduces its ability to pick up nitrogen or hydrogen. This can be enhanced by the further step, prior to introduction of the suspension, of adding pure lime to the melt to form a protective layer thereon. The vehicle gas for the powder of course is inert, normally argon. The vessel can also be sealed up with a tight cover after addition of pure lime to it and before introduction of the suspension. Otherwise in the subsequent desulfurizing nitrogen and hydrogen will enter into the metal matrix, especially if there is an appropriate slag present.

Abstract: This invention relates to the use of lanthanum in the production of iron-based alloys. Accordingly, is provided a method comprising adding at least 0.0001 to about 0.5 to 2 weight percent of lanthanum to said iron-based alloy during its production. Thus the solidification curve is modified, as shown in FIG. 2, thereby reducing or preventing certain defects of said alloys, such as pinholes and cavities in spheroidal graphite cast-irons, carbides in flaky graphite grey-iron; the castability, rollability and anisotropy of steels are improved.

Abstract: A device for swirling, through the bottom of a converter for refining liquid metals, by oxygen lance blowing, consisting of a set of single tube tuyeres, located throughout the entire thickness of the refractory coating of the converter and wearing away with the latter. The tube constituting each of the tuyeres is flattened along the whole consumable length (1b) of the tuyere, the width of the internal cross-section for the passage of the gas in the flattened tube (1b) is, at most, equal to 1.0 mm and, preferably, approximately 0.5 mm, the head (1a) of each of said tubes, generally cylindrical, passes through a steel plate (5) to which it is brazed, and the steel plate (5) constitutes one of the walls of a distribution chamber (6) between the swirling gas tuyeres, supplied with gas through a duct (7), the chamber (6) being fixed by means of the plate (5) to the exterior surface of the sheathing (8) of the converter.

Abstract: Ferro-silicon powder after pulverzation to a predetermined grain size is injected, preferably by a pneumatic medium, into molten iron to increase its silicon content, either alone or prior to a desulfurization treatment to make foundry pig iron with a low sulfur content.

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: A reduced iron installation includes transportable container having a charge/discharge mouth section provided with a sealing valve and a plurality of support legs and is arranged for 180.degree. rotation between a charge condition under a furnace to a discharge condition supported over the mouth of a storage tank via its legs, a weighing device for said container in its discharge condition, and a cluster remover disposed in the storage tank mouth and having a sealing valve which opens and closes, in response to detection signals from the weighing device indicating that the container is charged or empty, respectively. The cluster remover includes a grizzly feeder disposed obliquely within a cylindrical casing which is supported via an anti-vibration mounting on a fixed support surface, and a vibrating machine mounted on the casing.