Abstract: In a process for the reduction of fine ore by reducing gas in the fluidized bed method, the following characteristic features are realized in order to achieve a uniform and even degree of metallization at optimum utilization of the reducing gas and while minimizing the amount of reducing gas employed, that the fine ore is fractionated by aid of the reducing gas into at least two fractions having different grain size distributions, that each fraction is reduced by the reducing gas in a separate fluidized bed, wherein the reducing gas maintains a first fluidized bed containing the coarse-grain fraction and separates the fine-grain fraction from the same, is accelerated together with the fine-grain fraction, subsequently under pressure release forms a further fluidized bed, into which it is continuously injected in a radially symmetrical manner and from below, and wherein, furthermore, secondary reducing gas additionally is directly injected into the further fluidized bed in a radially symmetrical manner, and th

Abstract: A chrome-free conversion coating composition for use over zinc-plated metal comprises a combination of a transition metal oxide, and a polyhydroxy aromatic to provide a coating that eliminates environmental concerns regarding chromium disposal. Aluminum chlorohydrol is also included in the composition to provide an aesthetically pleasing blue appearance. The conversion coating composition is combined with water to form a bath. Zinc plated metal is immersed in the bath to apply the coating.

Abstract: Substantially improved hydrophilicity can be provided to a metal substrate, particularly an aluminum alloy of the type used for heat exchanger fins, that has been previously provided with a conventional chromium oxide conversion coating, by drying into place on the surface of the chromium oxide conversion coating an aqueous liquid hydrophilicizing treatment composition containing at least one of: (i) aproduct or products of reaction between dissolved phosphoric acid and at least one of elemental metal, metal oxides, and metal hydroxides in contact therewith; (ii) tungstate ions; and (iii) at least one of sulfate or molybdate ions together with polyethyleneimine. Most preferably, a solution formed by dissolving MgO in aqueous H.sub.3 PO.sub.4 in the proper stoichiometric amount to form an aqueous solution of Mg(H.sub.2 PO.sub.4).sub.2 with a pH of 4.5-5.5 is used for the hydrophilicizing treatment.

Abstract: A method of protecting copper and copper alloys from surface oxidation on an upper melted surface while melting copper and/or copper alloys, such as bronze, using a granular carbon sand layer thereover, such as the carbon sands disclosed in this assignee's U.S. Pat. Nos. 5,215,143 and/or 5,094,289.

Abstract: A method for reducing the corrosion potential of steel vessels and piping used in nuclear reactors, in particular steel vessels and piping carrying high temperature water and/or steam which has a concentration of oxygen therein. A metal hydride is added to the water, the hydrogen of such metal hydride combining with oxidizing agents, typically oxygen, present in the water to reduce the concentration of such oxidizing agents. In the preferred embodiment the metal of the metal hydride is a metal that is capable of reacting with oxygen to form a substantially non-water soluble and substantially electrically insulating compound on the surface of the steel, and in particular is one that may react with and become deposited or incorporated into a pre-existing thin oxide film layer on the surface of the steel to thereby render such thin oxide layer substantially non-electrically conducting.

Abstract: A process for forming a conversion coating on the surface of a metal, including: contacting the metal with an acidic solution containing an oxidant in order to initiate growth of a metal oxide cell structure on the metal surface; contacting the metal with water for a period of time sufficient to thicken the oxide and form a metal oxide containing layer of a desired thickness; and treating the metal with one or more rare earth elements in order to impregnate and substantially seal the metal oxide.

Abstract: Concentrates containing (a) an hydroxylamine sulfate accelerator, and (b) zinc, nickel, manganese, and phosphate ions are formulated into aqueous coating solutions for treating metal surfaces, such as ferrous, zinc, and aluminum surfaces. In the process of using this solution, hydroxylamine ions become depleted or reduced in concentration in the applied solution. A replenishing solution is added for reusing the solution until the replenished coating solution reaches a sulfate level of no more than 14 g/l.

Abstract: A plasma cold hearth melting process which provides an ingot of improved properties and including a plasma cold hearth melting furnace operated inside an air-tight chamber containing an inert gas, such as helium, at subatmospheric pressure levels. Raw material metals for a desired titanium or titanium alloy composition are supplied to a melting hearth located inside the chamber and heated by a plasma torch which utilizes an inert gas. The plasma torch melts the raw material metal thereby forming a molten pool of metal that is directed to at least one refining hearth. Plasma torches located in the refining hearths maintain the composition in a molten state as it passes through the cold hearth furnace to allow impurities present in the composition to be refined therefrom. After passing through the refining hearths, the molten pool of metal is poured into an ingot mold while still under subatmospheric inert gas pressure. The molten material is then allowed to cool and solidify into an ingot.

Abstract: The invention relates to a method for producing copper in a hydrometallurgical process from copper-bearing raw materials, such as sulfidic concentrates. The concentrate is leached in a leaching stage of several steps into a chloride-based solution. The copper-bearing solution obtained from this leaching is subjected to reduction and solution purification, whereafter the copper contained in the solution is precipitated as copper oxidule by means of alkali hydroxide. The alkali chloride solution formed in the production of copper oxidule is fed into chloride alkali electrolysis, where it is regenerated back into alkali hydroxide. The hydrogen generated in the electrolysis is used in the reduction of copper oxidule and in other reduction stages of the process. The formed chlorine is used in the leaching of the raw material. When necessary, the reduced copper that is in a granular or pulverous form is further subjected to melting and casting in order to produce commercial-grade copper.

Abstract: Niobium, Nb, is refined from FeNb by electron beam melt refining. The amount of the impurities in the FeNb which form suboxides with oxygen is optionally determined. Sufficient oxygen is added to form oxides with these impurities. The electron beam melt refining process is carried out at a sufficiently high temperature and under a sufficiently low vacuum so that the impurities are removed as oxides from the liquid Nb and the purified Nb is recovered. Preferably the oxygen is added as an oxygen-containing compound such as Nb.sub.2 O.sub.5. The recovered Nb can be subjected to additional electron beam melt refining cycles to obtain the desired purity.

Abstract: A method and apparatus for improved control of continuous electric arc furnace steelmaking in which a charge velocity detector measures charge velocity of metallic charge introduced to the furnace. A charge mass detector measures a charge mass of metallic charge introduced to the furnace. A computer determines a feed rate based on the charge velocity and the charge mass. An automatic bath level probe detects a steel bath. The computer determines a steel bath level and optimal positions to insert a temperature probe and an oxygen lance, and further predicts new bath levels from one tapping time to the next tapping time. The temperature probe is inserted to an optimal measurement position based on the steel bath level and measures a steel bath temperature. The oxygen lance is positioned and maintained at an optimal oxygen injection position and injects oxygen into the bath.

Abstract: The invention relates to a method to produce steel from a ferrous material, by using one furnace divided into, at least, two vessels which are connected to each other at least by ducts for the off-gases and ducts for the melted metal.

Abstract: Method and apparatus for melting reactive metallic materials, such as for example titanium base alloys and other reactive alloys, by selective and sequential induction heating of a plurality of solid alloy charge components segregated in a refractory melting vessel in a manner to effect rapid top-to-bottom melting that avoids harmful reaction of the melt with refractory melting vessel material and contamination of the melt.

Abstract: A titanium aluminide based alloy consisting of 42-48 at % aluminium, 2-5 at % niobium, 3-8 at % zirconium, 0-1 at % boron, 0-0.4 at % silicon and the balance, apart from incidental impurities, is titanium. The titanium aluminize alloy composition has a satisfactory combination of high tensile strength, acceptable ductility at room temperature and low secondary creep rate at elevated temperature, so as to be suitable for use in high temperature applications for example aero-engines and automobile engines. It is suitable for compressor discs and compressor blades of aero-engines.

Abstract: A method and system for recycling byproduct streams from metal processing operations introduces a flow of a molten mixture of salts, metal and metal oxides from a melting vessel into a flow of water. The molten salts dissolve into the water. The metal oxides, and any metal entrapped in the molten mixture, instantly fragment into small particles. The slurry of brine and small particles flows into a storage tank and from there the brine can be separated from the small particles by employing a series of known liquid-solid separation techniques which preferably utilize cyclones, centrifuges, thickeners, and filters. In the case of aluminum processes, an antioxidant is preferably provided in the holding tank. To increase the settling rate of the solids, a flocculent can be added in the thickener.

Abstract: A method for injecting fine iron ore in a smelting reducing process is disclosed, in which the carrier gas for the iron ore is the discharge gas from a melter gasifier without the need of separate carrier gas. It includes the steps of pre-reducing iron ore in a pre-reduction furnace, melting and reducing it in the melter gasifier, supplying the discharge gas from the melter gasifier through an ascending tube to a cyclone and to said pre-reduction furnace, directing the cooled and cleaned fine iron ore through a recycling system and a melting burner into the melter gasifier. A part of the discharge gas is supplied through a venturi scrubber, a first compressor and a circulating tube into an ascending tube. A part of the compressed gas circulating through the tube is recompressed by means of a second compressor and fine iron ore from a stored source is injected into ascending the tube by the recompressed gas by means of a pneumatic fine iron ore conveying system.

Abstract: Copper and nickel are extracted from their elemental state, complex sulfides, ores, and other materials such as scrap by leaching them with a solution containing halogen salts: bromine/bromide, or iodide/iodine, oxygen and sodium or potassium nitrate. The invented process is particularly effective for chalcopyrite and pentlandite in an autoclave at a temperature of 100.degree. C.-150.degree. C.

Abstract: To provide a Cu-Cr alloy electrode material, a mixture of Cu and cr materials at a predetermined ratio is heated until the mixture has been entirely melted, and the molten metal obtained is quenched to precipitate fine Cr particles in a Cu base. Since Cr is melted into Cu before quenching, and then Cr precipitates, Cr particles finer than those in the sintering or infiltration method can disperse in a Cu base. This invention prevents defects such as voids in the structure and the weakening of the fusion of Cu and Cr or failure of Cr to precipitate into the Cu base caused by oxide films on the surface of the Cr particles, thereby providing a fine alloy structure.

Abstract: A process for making an aluminum alloy lighting sheet product having a reflective surface protected by a UV-stable polymer coating. An aluminum alloy sheet is chemically brightened in an aqueous acidic solution, conversion coated, and then coated with a UV-stable polymer. Alternatively, an aluminum alloy sheet is chemically etched in an aqueous alkaline solution, conversion coated, and then coated with a UV-stable polymer. The UV-stable polymer may be clear or it may contain about 0.5-10 wt. % amorphous silica particles and polytetrafluoroethylene particles. In another embodiment, an aluminum alloy sheet surface is cleaned, chemically conversion coated and then coated with a coating composition containing a UV-stable polymer and 0.5-10 wt. % silica particles and polytetrafluoroethylene particles, both having an average size of about 0.5-5 microns.

Abstract: Heavy metals substantially free from heavy metal chloride contaminants are recovered from electric arc furnace (EAF) dust by bringing the dust into contact with a carbonaceous reductant utilizing a plasma arc of a DC sealed atmosphere plasma arc furnace so as to volatilize (vaporize) the hazardous heavy metals therein, and then bringing the vaporized heavy metals into contact with an alkali metal gettering agent to thereby form alkali metal chlorides and thereby substantially inhibit the formation of heavy metal chlorides in the off-gas.