Abstract: A low density, porous compact of prepared mix containing silica fume, finely-divided carbonaceous reducing agent such as petroleum coke or coal, optionally iron and a binder.

Abstract: A refractory gas-permeable structural unit for blowing a gas into a metal treatment vessel and through its casing has at least two elements composed of refractory material and having abutting longitudinal faces provided with at least one metal layer, a metal housing surrounding the elements to connect them with one another and tightly abutting against other longitudinal faces of the elements, and a gas distribution chamber formed at an end face of the elements and communicating with a gas supply conduit.

Abstract: A method of switching bottom blown gases and an apparatus suitable for carrying such method into practice in blowing successively in turn a plurality of gases through piping into molten steel in a steel-making furnace through tuyeres or porous plugs for gas blowing located in a lower portion of the steel-making furnace. The method includes the step of directly releasing into atmosphere at least a portion of the gas flowing in and through the piping in response to a rise in the pressure of the gas when switching the blown gases.

Abstract: The present invention provides a method for preliminary treatment of molten iron from a blast furnace wherein only desiliconization of the iron is effected. Gaseous oxygen is injected into the molten iron by controlling its supply rate depending on the Si content of the molten iron in such a manner that said rate is increased if the Si content of the iron is high and decreased if the Si content is low.

Abstract: A method for producing a vanadium- and nitrogen-containing material (V.sub.2 N) in which nitrogen gas is introduced into a furnace containing a mixture of V.sub.2 O.sub.3 and carbon in stoichiometric proportion while simultaneously maintaining the temperature in the furnace in a range of from about 1000.degree. C. to 1500.degree. C. under a reduced pressure in the range of from about 5 mm to 100 microns.

Abstract: A plasma reactor, in which particulate matter is caused to interact with low temperature plasma (i.e. below 100,000 K) comprises spaced stationary electrode structures 2, 11 of which at least one is annular, between which an arc or arcs 7 is established by a power supply which may include a thyristor (SCR) 9. The arc is pulsated and caused to orbit or circulate round the or each annular electrode structure to form a conical plasma zone between the electrodes, while particulate solids are introduced through inlets 5 to enter the plasma zone and interact with the plasma therein. Extended dwell periods and highly effective interaction are brought about by circulation and pulsation of the arc and a high particle population density.

Abstract: A process for the removal of harmful impurities, particularly arsenic, antimony, bismuth and lead, from metallurgical sulphide melts, in which the sulphide melt is sulphurated before conversion, during the slag-blowing stage or after it before the blister-blowing stage, and the melt is refined with nitrogen or other inert gas during sulphuration and possibly after it, so that the amount of sulphur supplied to the sulphide melt is at least 10% in excess of the stoichiometric sulphur amount as calculated from the sulphur requirement of the principal components of the melt.

Abstract: A gas injection nozzle design for use in a swirling tank reactor used in the degassing of molten metal with a fluxing gas. The nozzle design eliminates metal leakage from the reactor around the nozzle tip and gas leakage within the fluxing gas delivery line. The nozzle tip is provided with an orifice profile consisting of a straight hole opening of constant diameter or consisting of a converging-diverging profile.

Abstract: In order to enhance the CO concentration contained in exhaust gas generated during the refining of metal and to recover the CO as an energy source, granular limestone is blown into molten iron containing at least 0.3% of carbon through a tuyere together with a refining gas, and CO.sub.2 generated by the decomposition of the limestone is reacted with carbon contained in the molten iron to form CO, and the resulting CO is recovered.

Abstract: A desulfurization method in which an iron melt, carefully skimmed from slag in a ladle, is covered with about 1 to 2 kg. of lime per ton of iron, the melt is deoxidized to at most 35 ppm of oxygen and is then blown with a mixture of lime, calcium fluoride and metallic aluminum in an inert gas by means of a lance immersed in the bath so that the outlet of the lance is at an average depth of about 1500 mm below the bath surface.

Abstract: Metallurgical melting apparatus with a blow-nozzle or burner capable of swivelling in different directions. The blow-nozzle or burner comprises at least one tube. The nozzle-head (12) has a bulge, in the example described a spherical calotte (13), which is retained between two ring-seats (14 and 15) (the FIGURE).

Abstract: A process for dephosphorization, desulfurization and denitrification of chromium-containing pig iron comprising contacting the melt of said iron with a slag comprising not less than 10% and less than 40% of CaO, not less than 5% and not more than 40% of iron oxides and more than 40% and not more than 80% of CaF.sub.2 in which the content of SiO.sub.2 as an impurity is not more than 10% and that the ratio %CaO/%SiO.sub.2 is not less than 3 is disclosed. According to this process, oxidation dephosphorization of chromium-containing pig iron is effectively and economically achieved. Simultaneously desulfurization and denitrification thereof are effected, too.

Abstract: A process or method of and apparatus for the in-ladle treatment of molten base metal iron with a nodularizing agent (e.g., a magnesium bearing alloy) so as to produce substantially uniform spheriodal graphite in the iron. The process involves placing a desired quantity of the nodularizing agent in a reaction chamber in a treatment ladle, the latter having a main chamber, a charging and filling passage leading to the reaction chamber, and one or more passages leading from the reaction chamber to the main chamber of the ladle. Molten base metal iron is then poured into the reaction chamber via the charging and filling passage thereby to effect a reaction between the nodularizing agent and the molten base metal. A hydrostatic pressure head of the molten base metal is rapidly established over the reaction chamber of sufficient depth thereby to minimize the vaporization of the nodularizing agent and to maximize the recovery of the nodularizing agent in the base metal.

Abstract: A molten metal is fed into a ladle and subjected to vacuum while being treated with inoculating additives. The application of vacuum is carried out prior to the beginning of interaction between the melt and the inoculating additives, and is conducted continuously for 15 to 120 seconds in the course of this interaction. A receiving tank is provided with a discharge opening which is closed with an insert, a ladle having load trunnions is disposed under this tank with a sealable chamber. A system of air evacuation is provided for the chamber whereby on disintergration of the insert the molten metal with tank enters the chamber and is subjected to the vacuum.

Abstract: Metallurgical melting and refining unit (21) with which scrap steel, sponge iron, solid and molten pig iron can be processed in any desired ratio of admixture, and coal, oil, gases or electrical power can be used as energy source. For this purpose, and with an eye to low investment costs, the furnace vessel (22) is made in the form of a round hearth furnace with a ratio of the inside dimensions diameter (d) to height (h) of the furnace vessel between 0.8 and 2.5, and one tuyere bench (33) is provided on each side of the tap hole (10), for primary tuyeres which discharge below the melt surface. Furthermore, two tuyeres (25) discharge into the furnace vessel above the melt surface and are constructed as burners. The charge material can be preheated and charged in a controlled manner by a scrap preheater (27) whose floor consists of gas-permeable grate parts (30, 31) which can be opened from the center. (FIG.

Abstract: In a process for the gasification of solid carbonaceous material such as coal, powdered coal is top-blown onto a molten iron bath stored in a furnace through a non-submerged lance toward a hot spot formed by means of a jet of oxygen and steam top-blown through a non-submerged lance, coal being blown by means of a carrier gas, and flux is optionally added into the furnace by the lump or blown toward the hot spot, thereby the coal being gasified. The ratio L/L.sub.o of the depression depth L of the molten iron bath to the molten iron bath depth L.sub.o is maintained from 0.05 to 0.15, and the blowing velocity of the solid carbonaceous material is maintained from 50 to 300 m/sec so as to suppress the forming of an adhered mass in the furnace. A stirring gas is blown through a bottom nozzle to stir the molten iron bath.

Abstract: A method and apparatus for concurrent introduction of molten steel and gas-fluidized chemical steel additives, such as chemical desulphurants, into a teeming ladle 10. Injection apparatus includes a lance 52 arranged to remain with the vessel. Introduction of gas-fluidized additives through a lance opening 81 is commenced while a charge of molten steel is introduced into the ladle. The lance is unobstructed at its discharge end and in one embodiment is carried directly by a discharge stopper 31".

Abstract: Alloying ingredients are added as shot to a pouring stream of molten steel flowing from a ladle to a casting mold. The size of the shot is controlled to enhance the recovery and uniformity of distribution in the steel of the alloying ingredients.

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: The metal content of complex sulphidic metal raw material is recovered therefrom by means of an autogenous flame-smelting process, preferably carried out in a vortex, with an oxygen-containing gas. The raw materials are smelted in a furnace in the presence of an excess of oxygen and together with an addition of an acid slag former, such as silica, to form a melt which is rich in metal-oxide silicate and poor in sulphur. Any metal phase formed in the furnace is separated from the silicate phase, and non-iron metals present in the silicate phase are recovered therefrom by selective reduction.