Abstract: A phase contrast microscope includes a light source, an illumination optical system configured to irradiate an observation object with the light from the light source, and a magnifying optical system configured to magnify and project the observation object, the illumination optical system includes a ring slit, the magnifying optical system includes an objective provided with a phase film, the ring slit is disposed at a pupil position of the illumination optical system, the phase film is disposed at a position conjugate to the pupil position of the illumination optical system, and the following conditional expression (1) is satisfied: r/I?0.25??(1) where r is a central part radius of the phase film, and I is a radius of a pupil of the objective.

Abstract: Feedstock supply structure apparatus, including an exhaust conduit fluidly and mechanically connectable to a structure defining a melting chamber, the exhaust conduit positioned at an angle to vertical ranging from 0 to about 90 degrees. The exhaust conduit may include a heat exchange substructure, or the conduit itself may serve as a heat exchanger. A feedstock supply structure fluidly connected to the exhaust conduit. Systems include a structure defining a melting chamber and an exhaust conduit fluidly connected to the structure. The exhaust conduit includes a heat exchange substructure for preheating the feedstock. Methods include supplying a granular or pellet-sized feedstock to the melter exhaust conduit, the exhaust conduit including the heat exchange substructure, and preheating the feedstock by indirect or direct contact with melter exhaust in the heat exchange substructure.

Abstract: Apparatus includes a first and second conduits configured to form an annulus between them. An adjustable structure includes a body having an upper surface, a lower surface, and a circumferential surface abutting a portion of the internal surface of the second conduit. The structure is adjustable axially in relation to and removably attached to the first conduit via a hub. The hub defines a central passage for fuel or oxidant. The body has one or more non-central through passages configured such that flow of an oxidant or fuel therethrough causes the fuel or oxidant to intersect flow of fuel or oxidant exiting from the central passage in a region above the upper surface of the body.

Abstract: A method and system for making metallic iron nodules with reduced CO2 emissions is disclosed. The method includes: assembling a linear hearth furnace having entry and exit portions, at least a conversion zone and a fusion zone, and a moving hearth adapted to move reducible iron bearing material through the furnace on contiguous hearth sections; assembling a shrouded return substantially free of air ingress extending adjacent at least the conversion and fusion zones of the furnace through which hearth sections can move from adjacent the exit portion to adjacent the entry portion of the furnace; transferring the hearth sections from the furnace to the shrouded return adjacent the exit portion; reducing reducible material in the linear hearth furnace to metallic iron nodules; and transporting gases from at least the fusion zone to the shrouded return to heat the hearth sections while in the shrouded return.

Abstract: In a process and an apparatus for the production of liquid metal (4) from fine-grain metal oxide particles, the particles, together with hot reducing gas, are blown against a heated bulk material filter layer (9) of lump coal and/or ceramic pieces, a substantial proportion of the particles being retained on and in the filter layer and subjected to finishing reducing by the reducing gas. A high-temperature flame is produced in front of the filter layer (9) by an oxygen-bearing gas being blown against the filter layer, and the metallised particles which are retained in the filter layer are melted. They pass in the liquid condition through the filter layer (9) into a receiving space (3) for liquid metal (4).

Abstract: The present invention relates to a process for the production of ferrosilicon in a closed two-stage reduction furnace. In the present invention, carbon monoxide released as a result of the smelting process, in the first stage of the furnace, is used to prereduce higher oxides of iron, for example Fe.sub.2 O.sub.3 and Fe.sub.3 O.sub.4, contained in a second stage of a furnace, to iron monoxide (FeO). The iron monoxide is then used as a feed material to the first stage of the furnace. The use of a closed furnace and a pre-reduction process results in substantial energy savings in the production of ferrosilicon alloy.

Abstract: A vertical shaft melting furnace wherein meltable solids are charged to the upper region of a bed supported only by a fluid cooled support grid having openings smaller than the average diameter of the charged solids wherein submerged combustion is maintained in a melt pool below the bed of solids and combustion product gases of the submerged combustion are passed upwardly through the bed of solids preheating and melting a substantial portion of the solids forming melt which flows downwardly into the melt pool and partially melting the remaining portion of the solids reducing their size sufficiently to pass through the support grid openings into the melt pool. The apparatus and process of this invention provides improved melt quality with stable temperature and high homegeneity with increased specific production rate and increased unit production rate.

Abstract: A process for the continuous leaching of ores and an apparatus for practising this continuous leaching process are disclosed. According to this process, a plurality of unit layers composed of a pulverized uranium ore or other ore are continuously laminated while a minimum necessary amount of an acid, alkali or organic solvent (hereinafter referred to as "solvent") is uniformly sprinkled on the flat surfaces of these unit layers. In the state where the concentration of the solvent mixed into the ore is maintained at a high level, the heat generated by exothermic reaction caused by contact among the solvent, ore and water is effectively stored and used for thermally curing the ore. According to this process, the speed of extraction of the intended metal component can be increased, the leaching time shortened and the filtration characteristics improved, whereby a highly concentrated pregnant liquor can be recovered at a high efficiency.

Abstract: A method and apparatus for the direct reduction of iron ore are disclosed. A mixture of iron ore, solid carbonaceous fuel and, if sulfur is present, calcined limestone or dolomite, are used. The carbonaceous material can be cellulosic material (wood waste, paper, particularly municipal trash, garbage, etc.), charcoal, or coal (preferably sub-bituminous coal or lignite). The above feed is continuously charged into a gasification and initial reduction zone of a shaft furnace which is partitioned partially from the remainder of the furnace. Oxygen and hot steam are introduced into the upper portion of the said zone. Partial combustion or pyrolysis of the fuel and reaction with steam take place, producing reducing gas which initiates reduction of the iron ore. Ore and gas flow downwardly through conduits into the final reduction zone. Meanwhile, hydrogen-enriched reducing gas is introduced in the middle of the final reduction zone.

Abstract: Steam curable agglomerates of particulate material are cured by passing steam at elevated temperature and pressure through a bed of such agglomerates in an autoclave. The flow direction of the steam through the bed is periodically reversed, at least during the temperature raising period of the autoclaving process, to reduce the autoclaving time and produce cured agglomerates of substantially uniform quality.