Abstract: A process for producing potassium and silicon doped molybdenum (KS molybdenum). The process involves mixing an aqueous ammonium molybdate solution and a dilute aqueous potassium silicate solution. The molybdate solution has a pH and a specific gravity sufficient to promote formation of diammonium molybdate crystals in the mixture. Preferably, the pH is about 8.8-11.0 and the specific gravity is about 1.20-1.32. The amount of potassium silicate and the amount of potassium silicate solution are selected to provide predetermined amounts of potassium and silicon in the mixture, preferably about 800-1300 ppm potassium and about 500-1100 ppm silicon, both amounts based on the amount of molybdenum. The mixture is heated to aid dissolution of the potassium silicate and ammonium molybdate in said mixture and to produce a homogeneous solution of ammonium molybdate, potassium, and silicon.

Abstract: A three-stage process for obtaining metallic Cr units insitu during the production of stainless steel. Raw chromite ore or a concentrate produced from chromite ore is mixed with a carbonaceous reductant and slagging agents are added to an iron bath (24) for smelting and refining in a refining reactor (10). During the first stage, partially metallized chromite is smelted by carbon in the reactor that is top-and bottom-blown with oxygen and oxygen-containing gases respectively to produce a chromium alloy bath having a carbon content well below saturation. In the second stage, the alloy bath is decarburized by being bottom stirred with the oxygen-containing gas to the final bath carbon specification. In the third stage, the alloy bath is reduced by a metalloid reductant such as silicon or aluminum and again bottom stirred but with a non-oxidizing gas to achieve a high chromium yield.

Abstract: Disclosed is a manufacturing process of an alloy material comprising a chromium component and a base component which comprises at least one element selected from tile group consisting of copper and silver, the manufacturing process comprising steps of: subjecting a chromium material with a carbon material to heat treatment; and manufacturing the alloy material using the chromium material treated at the heat treatment subjecting step and a raw material for tile base component. At the heat treatment subjecting step, the chromium material, mixed with 50 ppm to 5,000 ppm of the carbon material, is heated to a temperature within the range of 800.degree. C. to 1,400.degree. C. in a non-oxidizing atmosphere. According to this manufacturing process, the level of oxygen content in the alloy material are decreased to be not more than 200 ppm. The obtained alloy material can be used as a contact material for vacuum circuit breakers.

Abstract: There is proposed a novel method for manufacturing high-purity metallic chromium that can eliminate the problems of reduced heating capability of the furnace, contamination of produced metallic chromium and other disadvantages related to the operation of the furnace. According to the invention, one or more than one of easily sulfidable metals selected from Sn, Ni and Cu are added to crude metallic chromium containing impurities and the mixture is loaded into a vacuum furnace equipped with heating elements of graphite and heated to 1,200.degree. to 1,500.degree. C. in an atmosphere with reduced pressure of between 0.1 and 5 torr.

Abstract: A molybdneum, rhenium, and tungsten alloy having an improved erosion, ductility, strength and a higher recrystallization temperature. The alloy may be fabricated into equipment which is useful for manufacturing chemicals such as a hydrochlorofluorocarbon.

Abstract: A smelting process for blending hazardous and non-hazardous inorganic industrial wastes with carbon or aluminum reducing agents to simultaneously recover metal alloys (reducible metals), metal oxides (volatile reducible metals), carbon dioxide and man-made vitreous fiber (non reducible metals). Wastes including hazardous wastes of U.S. EPA Series D, F, P, K, and U are pulverized and blended with liquids such as water or waste water to produce a homogeneous mass. The mass is formed into briquettes and melted in a cupola or plasma arc furnace in the presence of carbon or aluminum to reduce metals. Other types of furnaces such as an electric arc furnace may be used to avoid the steps of forming and curing briquettes. Reduction is carried out at temperatures between 1660 and 3100 degrees Fahrenheit. Calcium flux from calcium-stabilized wastes enhances mineral wool quality, lowers the sulfur content of metals and raises pH to facilitate metal reduction. Reducible metals are reduced and drawn off into molds.

Abstract: Flowable molybdenum metal powder of controlled particle size distribution is produced by stage-wise reduction wherein, in a first stage, molybdenum trioxide feed is preferably introduced at depth in a fluid bed of molybdenum dioxide and is reduced in an atmosphere containing at least 50% hydrogen, by volume, at a temperature between 560.degree. and 620.degree. C. and the product molybdenum dioxide is then reduced to molybdenum metal in a second stage fluid bed at a temperature between 1025.degree. C. and 1075.degree. C. in an atmosphere containing at least 50% hydrogen employed in amount of at least 2.75 times stoichiometric while controlling the off-gas dewpoint to be at least 21.degree. C. and controlling the off-gas hydrogen:water vapor ratio so as not to exceed 24:1 and removing the product spheroidal molybdenum metal particles from the bottom of the bed to prevent collapse of the bed.

Abstract: The specification discloses a process for producing a ferroalloy in a smelting vessel. A material containing an alloying metal is injected into a molten bath contained in the vessel. A flux, a carbonaceous material and an oxygen-containing gas are also injected into the vessel. A gas which may be the oxygen-containing gas is injected into the molten bath in order to stir it. The rates of injection of the various components are controlled to achieve control of the oxidizing and reducing environment within the vessel consistent with a rapid rate of injection. The material containing the alloying metal is either reduced and incorporated into the metal phase or oxidized and incorporated into the slag. Combustion gases above the molten bath are oxidized to provide further heat to the process. Alloyed metal or slag containing the alloying metal are recovered as product. The process is applicable to the production of ferroalloys such as ferrochromium, ferromanganese, ferronickel and ferrovanadium.

Abstract: Chromium carbide powder and/or powder of an easily sulfidable metal are added to powdered crude metallic chromium to form a mixture thereof, which is then heated in vacuum to remove S, N and O by degassing so that consequently the crude metallic chromium is free from impurities to a possible maximum extent.Alternatively, powdered crude metallic chromium is heated in an atmosphere of inert gas to temperature between 800 and 1,400.degree. C. and then an easily sulfidable metal is added thereto to form a mixture thereof. Subsequently, the mixture is, directly or after adding carbon or chromium carbide, heated again in vacuum or in an atmosphere of inert gas to eliminate S, N and O by degassing so that the crude metallic chromium is free from impurities to a possible maximum extent.Still alternatively, powdered crude metallic chromium is washed with inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid or organic acid such as acetic acid to remove metal impurities such as Fe.

Abstract: In situ formation of metal-ceramic oxide microstructures is carried out on a starting oxide phase containing at least a most noble metallic component (e.g., iron) and a least noble metallic component (e.g. manganese) and subjecting the starting oxide phase to a temperature and oxygen partial pressure and for a time period to cause reduction of only part of the most noble metallic component to elemental metal.

Abstract: A method for forming a porous body of a metal from the group consisting of molybdenum, molybdenum alloy, tungsten, tungsten alloy, or mixtures thereof comprises foaming a mixture of a sinterable powder of the metal and a foaming agent in a volume ratio of about 0.6 to 3.5:1 respectively, to form a foam having the metal powder dispersed therein. The foam is heated in a reducing atmosphere that promotes interparticle diffusion and bonding, to decompose the foam and sinter the metal powder to form the porous body.

Abstract: The specification discloses a process for pre-heating and pre-reducing metal oxide ores. The process comprises introducing particles of an oxide ore entrained in a gas through a port into a treatment chamber. Inside the treatment chamber teh stream of entrained particles combines with a stream of high temperature reducing gas in such a way that the particles are heated rapidly and enter into flow patterns whereby contact with other particles and the internal surface of the treatment chamber is minimized. The stream of entrained particles and the stream of high temperature reducing gas are substantially co-current. A treatment chamber elongated in the direction of co-current flow is described in the specification. The hot off-gases may be derived from a molten bath reactor and comprise a high concentration of carbon monoxide and hydrogen.

Abstract: A method and apparatus for producing molten metal from powder state ore through smelting process to be performed in a shaft furnace, utilized the reducing material having grain size greater than that n-times of the gas flow velocity corresponding grain size to charge from the top of a shaft furnace for forming fluidized bed at the upper section of the furnace and a reducing material filled section below the fluidized bed. The method and apparatus for smelting the powder state ore also takes the reducing material having smaller grain size to be blown into the furnace through tuyeres.

Abstract: Tungsten metal powder of controlled particle sizes is obtained in a fluid bed process by reducing particles of tungsten oxide having the formula WO.sub.X where x is from 2.5 to 3.0. The WO.sub.X powder particles are heated to and then maintained at a temperature between 650.degree. and 1000.degree. C. in a reducing atmosphere, which is maintained by passing a mixture of hydrogen gas, water and optionally nitrogen gas through a fluid bed of the tungsten oxide particles until substantially all of the powder solid is tungsten dioxide, WO.sub.2. The ratio of water partial pressure to hydrogen partial pressure in the feed gas is equal to or slightly higher than the equilibrium partial pressure ratio. The flow of water vapor is then discontinued, either gradually or instantaneously, while maintianing the flow of hydrogen gas to reduce the WO.sub.2 to tungsten metal. By maintaining the ratio of water partial pressure to hydrogen partial pressure above the equilibrium value until the original WO.sub.

Abstract: A process for enhancing fluidization in a fluidized bed reactor chamber. In a preferred embodiment, molybdenum oxide is reduced to molybdenum metal in the fluidized bed. An oxidant is introduced into the fluidized bed during the reducing process in order to substantially prevent or reverse the agglomeration of the particles.

Abstract: A method for manufacturing a low carbon ferrochrome with a high chromium content of at least 70 weight % Cr comprising the steps of at least once nitriding and crushing a low carbon ferrochrome to form a crushed ferrochrome nitride and subjecting the crushed ferrochrome nitride to an acid treatment comprising introducing the crushed ferrochrome nitride into an acid solution and stirring the resultant mixture of the ferrochrome nitride and the acid solution, to remove iron. The acid treated ferrochrome nitride is denitrided by heating in a vacuum.

Abstract: High-purity metallic chromium is produced by a method of initially preparing a mixture of chromium oxide, aluminum, carbon and an easily sulfidable metallic powder, and subsequently providing a thermite-reaction with the mixture to produce thermite-crude metallic chromium and a solid solution of carbon and easily sulfidable metal. Residual impurities in the thermite-crude metallic chromium are subsequently removed by heat treating the crude metallic chromium. This method produces high-purity metallic chromium advantageous for preparing corrosion and heat resistant chromium-containing alloys.

Abstract: A reduced chromium-ore bearing powder used for production of a chromium-containing steel in a converter, is produced by a reduction of chromium ore-powder having a particle-diameter of 3 mm or less by a carbonaceous reducing agent having a particle diameter of 3 mm or less in an inert-gas atmosphere, while the chromium-ore powder and carbonaceous reducing agent are stirred and mixed with each other in the reaction chamber (5).The reduced chromium-ore powder has 3 mm or less of particle diameter. Acid-soluble chromium is in an amount of 85% or more of the total chromium, and acid-soluble iron is in an amount of 95% or more of the total iron.

Abstract: Reduction of chromium oxide is performed by utilizing refinement or reduction container having top-blowing capability. Chromium oxide is charged in the molten iron bath in the aforementioned container. Content of slag is adjusted to maintain the following condition:CaO/SiO.sub.2 :2.1 to 3.5MgO/Al.sub.2 O.sub.3 :0.6 to 0.

Abstract: The present invention relates to a method for production of metals and/or ferro alloys by prereduction of particulate metal oxide co-current with a reducing gas. Reducing gas having a temperature between 650.degree. and 1100.degree. C. and metal oxide particles are supplied at the lower end of a substantially vertical prereduction column which comprises at least two chamber having a substantially circular cross-section, said chambers in their upper and lower ends having a decreasing cross-section and where a ringshaped member for decreasing the cross-section is arranged in the intermediate zone between the chambers. The mixture of reducing gas and prereduced metal oxide particles is collected at the top of the prereduction column, whereafter the prereduced metal oxide particles are transported to a smelting furnace for smelting and final reduction to metallic state by addition of a reduction material.The present invention also relates to a column for treatment of particulate solid materials with a gas.

Abstract: The present invention relates to a method of carrying out a smelting reduction of Cr raw material as Cr ores, Cr ore pellets and so on for directly producing high Cr molten metal in a furnace provided with bottom gas blowing tuyeres, side gas blowing tuyere and a top blowing lance. An inert gas is blown from the bottom tuyere to form an upheaving part on the surface of the molten metal, and an inert gas is blown from the side tuyere against the upheaving part, whereby the molten metal is diffused into a region of the slag where Cr raw material fly so as to accelerate reduction of Cr raw materials by C in the molten metal. On the other hand, O.sub.2 for decarburization is blown from the top lance into the molten metal, and at the same time O.sub.

Abstract: This invention relates to a method of checking flying losses of ores and coal when they are charged for carrying out smelting reduction of Cr ores and iron ores. In the invention, the raw materials are charged into the furnace through a chute extending nearly a mouth of the furnace or connected to a furnace body. Further, while gas is jetted toward an outside of the chute from a nozzle provided in an circumferential direction of an inside nearly the end of the chute, thereby to enable to exactly check the flying losses of the raw materials.

Abstract: Waste materials containing chromium, such as the sludge resulting from neutralization of chromic acid bleed streams from metal cleaning and plating operations, are (1) rendered innocuous for land fill purposes by heating to temperatures of at least about 700.degree. C. to stabilize the materials for safe disposal and (2) activated by heating to temperatures of about 400.degree. to 500.degree. and the chromium content in the resulting calcine can be recovered by thermite reduction.