Abstract: In the reduction of liquid slags or molten salts which contain nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal oxides and are disposed over a liquid metal layer consisting of the corresponding nonferrous metal, carbonaceous reducing agents and oxygen-containing gas are injected through nozzles into the metal layer. In order to improve the gasification of the reducing agent the height of the metal layer is so selected that at least 50% of the reducing agent are reacted to CO and optionally H.sub.2 in the metal layer before the reducing agent enters the slag layer.

Abstract: The present invention provides an improved method of extracting zinc from geothermal brines and synthetic brines which can be performed in a continuous, in-line process and which provides for the advantageous recycling of NH.sub.3 in the process.

Abstract: Describes a process for separating metallic mercury from soil containing same by producing an aqueous pulp of the contaminated soil in a mixing tank (12), screening the pulp in screening means (14) to separate a coarse fraction, further screening the pulp in screening means (17) (19) to produce a fines fraction, charging said fines fraction to solid-solid separating means (20) (24) to provide a first aqueous soil slurry (83) that is substantially free of metallic mercury and a second aqueous soil slurry (75) (81) containing metallic mercury, charging the second aqueous soil slurry to froth flotation cell means (28), thereby to provide a metallic mercury-containing froth (90) and an aqueous soil slurry (87) substantially free of metallic mercury, removing the froth from the flotation cell, and separating metallic mercury that settles out of the froth (95). Soil slurry substantially free of metallic mercury is flocculated (32), dewatered (35), filtered (36) and removed to a landfill (9).

Abstract: There is produced by an air distillation apparatus (4) a desired fraction of air from the stream of air leaving at least one blower (3) of the blast furnace, and there is sent to the blast furnace the oxygen produced by this distillation apparatus. The distillation apparatus comprises an air/liquid oxygen mixing column which operates at about 1 bar above the delivery pressure of the blower (3) and which directly produces the oxygen for enriching the air.

Abstract: The present invention relates to a process for directly smelting ores, metal oxides or the like with a thermal plasma.The direct smelting process of the invention can be practiced easily by simple equipment regardless of the form of the material to be smelted without using any plasma forming gas.The present process is characterized in that a polyphase current voltage is applied to a multiplicity of graphite electrodes to cause arc discharge in air and produce a strongly reducing nontransferred plasma arc due to the resulting oxidation decomposition of the graphite electrodes. The plasma arc is jetted out from the tips of the electrodes directly against the material to be smelted.

Abstract: A method of making iron involves using waste polymer material as a solid fuel charged to an iron melting vessel and/or using gaseous decomposition products from pyrolysis of waste polymer material as a gaseous fuel supplied to the vessel. Relatively large quantities of waste polymer materials can thereby be disposed of without landfill usage, while a substantial portion of their energy value is recovered for heating and melting the iron-bearing material in the vessel. The waste polymer material may comprise reaction injection molding compounds and precursors thereof, sheet mold compounds and precursors thereof, car fluff (i.e., non-metallic residue from the recycling of automobiles), scrap rubber tires and the like. Waste sheet molding compounds including calcium carbonate filler can be charged to the iron-making vessel such that the calcium carbonate therein is released and functions as a flux at the iron-making temperature involved to remove impurities from the iron.

Abstract: The present invention provides a novel method of extracting zinc from geothermal brines and synthetic brines which can be performed in a continuous, in-line process.

Abstract: Iron ore concentrate is converted to magnetic gamma hematite in an autogenous roasting operation which is self-sustaining. The iron ore concentrate is preheated and contained magnetite is oxidized to hematite. Hematite is reduced to magnetite using carbon monoxide. After cooling, the magnetite is oxidatively exothermically converted to magnetic gamma hematite. The thermal energy resulting from the latter step is recycled to the preheating and reduction steps while thermal energy resulting from the cooling step also is recycled to those steps. The magnetic gamma hematite may be subjected to magnetic separation to produce a very low silica high purity iron oxide concentrate, which may be blended with high silica concentrate to provide a pellet feed for making blast furnace feed pellets.

Abstract: A method is disclosed for melting copper without incorporating unwanted oxygen and/or hydrogen into the copper by effectively controlling the burners used to melt the copper within desired fuel/air ratio operating limits by employing a special fuel/air mixture sampling and control system.

Abstract: Complex ores of the precious metals which also contain iron spinels and similar compounds are assayed and their precious metals content is extracted by subjecting the ores or concentrates thereof together with an iron-embrittling agent to a pyrometallurgical process which reduces at least a major portion of the iron compounds to liquid metallic iron. The liquid iron serves as a collector metal for the precious metals and, after cooling, the iron is brittle and easily comminuted and can be separated from the precious metals through use of either an electrolytic process or a selective chemical dissolution of the iron and other base metals leaving the precious metals available for analysis and recovery.

Abstract: This non-blast process for the production of pig iron, cast iron, steel melt and nearly pure iron is carried out in a single furnace based on a tank-type design. Said types of iron melt can be produced in such single furnace individually or simultaneously in different combinations. The furnace interior is divided into immediately adjacent side-by-side chambers, at least one being an ore reduction chamber and at least one being a secondary chamber. Ore introduced into the top of the ore reduction chamber moves downward to the bottom of this chamber and is at first converted into sponge iron, which, absorbing carbon, is then converted into iron-carbon alloy in the form of a flowable layer at temperatures close to its melting point at about 1150 degrees C. while said flowable layer is collected on the bottom. In the melting zone of the secondary chamber such flowable semifinished product is completely melted, producing pig iron.

Abstract: A method for making a light metal-rare earth metal alloy comprises adding a pellet to a substantially flux-free bath of molten light metal, said pellet including a mixture of rare earth metal-containing compound and one or more light metal powders. On a preferred basis, such mixtures comprise scandium oxide, up to about 10 wt. % aluminum powder and a substantial majority of magnesium powder, all of which are substantially similar in median particle size. This mixture is preferably compacted under a pressure of about 7 kpsi or more, then added to a bath of molten magnesium or molten aluminum to make magnesium-scandium, magnesium-aluminum-scandium, or aluminum-magnesium-scandium alloys therefrom. There is further disclosed a method for making an alloy containing about 7-12 wt. % lithium, about 2-7 wt. % aluminum, about 0.4-2 wt. % scandium, up to about 2 wt. % zinc and up to about 1 wt. % manganese, the balance magnesium and impurities.

Abstract: A plant for the production of molten metals, includes a melting vessel and a metallurgical vessel receiving the melt from the melting vessel for aftertreating the melt and closed by a lid. The melting vessel has a tap opening for the melt provided on the bottom level of the melting vessel and located on the periphery of the melting vessel. The tap opening is positioned above a pour-in opening of the metallurgical vessel. In order to ensure a continuous melting procedure, the pour-in opening of the metallurgical vessel following the melting vessel is provided above a melt guiding chute arranged within the metallurgical vessel.

Abstract: A process for producing pig iron is described, which contains a reducing shaft furnace 1 and a melting gasifier 2. The sponge iron produced from iron ores in the reducing shaft furnace is supplied to the melting gasifier and converted there into a pig iron melt. The gas produced in the melting gasifier is supplied directly via a line 4 as reducing gas to the reducing shaft furnace. The blast furnace gas passing out of the reducing shaft furnace, after traversing a CO.sub.2 scrubber 6, is at least partly heated in a heat exchanger to 200.degree. to 500.degree. C. and passed to a partial combustion plant 13 where, accompanied by the addition of oxygen, the gas is heated to the necessary reducing temperature.

Abstract: A method and apparatus are described for recovering gold from aqueous slurries of refractory gold ores containing sulfidic and/or carbonaceous matter. The method entails pretreating an ore slurry with chlorine in a multi-compartment autoclave operated at an elevated pressure. The chlorine used in this pressure chlorination pretreatment can be in either the gaseous or liquid state. Following the removal of residual chlorine from the pretreated ore slurry, said slurry is transferred to a conventional cyanide leach/carbon adsorption circuit to recover the gold values.

Abstract: Geothermal brines are passed through a bed of an anionic resin selective to the removal of boron while maintaining a pH value between about 4 to 5.5 to load the boron on the resin from which the boron is thereafter recovered. If the brine contains large quantities of constituents have Lewis acidities greater than boric acid, these constituents are preferably removed before the boron is recovered. The invention is particularly applicable to geothermal brines of temperature above ambient, e.g., 90.degree. C. and above, such as 95.degree. C. and above.

Abstract: The maximum useful rate of aluminum refining is substantially increased by the incorporation of baffle means across the refining chamber under the rotor of a spinning nozzle assembly positioned in the refining chamber during aluminum refining operations.

Abstract: There are disclosed a method and an arrangement for preventing the agglomeration of crusts in a lance opening passing a wall of a metallurgical vessel and provided for a lance carrying a measuring and/or sampling probe. During the metallurgical process proceeding within the metallurgical vessel and during the taking of a measurement and/or sample by means of a lance introduced into the metallurgical vessel through the lance opening, a gas that is inert relative to a melt bath contained in the metallurgical vessel, or air, is injected into the lance opening from outside, which gas produces a gas veil at the mouth of the lance opening facing the melt bath.

Abstract: An improved process for deleading debismuthized dross is provided wherein the upgraded dross is treated by cupellation to form a slag until the level of bismuth in the upgraded dross reaches about 45% by weight. After cupellation, the partially deleaded upgraded dross may be treated by conventional means such as halogenation to provide a substantially pure bismuth product.

Abstract: Method of producing pig iron in a blast furnace. At least a portion of a top gas from a blast furnace is collected, dried and then heated to an elevated temperature preferably in the range of 900.degree.-1000.degree. C. An oxygen-enriched hydrogenaceous fuel is introduced into the furnace bosh and the heated dried top gas is introduced into the lower half of the furnace stack above the furnace bosh at a point above which the coke in the furnace is not reactive.