Abstract: In an embodiment, the present invention relates to an apparatus and a process for producing a concentrated form of basic zinc sulphate from a, typically dilute, acidic zinc sulphate-bearing solution. The process embodiment comprises the steps of precipitating the zinc, preferably primarily as basic zinc sulphate, from the acidic zinc sulphate solution, preferably using calcium oxide, in such a way as to promote the formation of separate gypsum crystals and basic zinc sulphate particles, and upgrading the zinc content in the precipitates by separating the basic zinc sulphate from the gypsum using size separation techniques.

Abstract: The present invention discloses a new recovery of base metals from sulphide ores and concentrates, which comprises mixing the base metal's ore with ferric salts, heating the said mixture; adding water to form a pulp, stirring and filtering the pulp.

Abstract: Process for melting scrap metal in a furnace comprising the steps of feeding a charge of solid scrap metal to the furnace, supplying fuel and an oxygen-rich oxidant to the furnace and combusting the fuel with the oxidant to generate heat inside the furnace, melting the charge of solid scrap metal in the furnace by means of the heat, withdrawing the molten metal from the furnace. Following the step of feeding the charge of solid scrap metal to the furnace, the fuel is combusted with the oxidant so as to generate one or more visible flames in the furnace above the charge and before the step of withdrawing the molten metal from the furnace, the fuel is combusted with the oxidant so as to generate flameless combustion in the furnace above the molten metal.

Abstract: A simple, compact burner achieves a more optimal melting of a solid charge followed by performance of combustion under distributed combustion conditions. The burner achieves this by fluidically bending the flame towards the solid charge during a melting phase with an actuating jet of oxidant, redirecting the flame in a direction away from the charge, and staging injection of oxidant among primary and secondary portions during a distributed combustion phase.

Abstract: Liquid metal is continuously recovered by condensing metal vapour in a sealed system, more or less at atmospheric pressure, and collecting liquid metal in a crucible. The contents of the crucible are agitated and the temperature is controlled to prevent the liquid metal from solidifying. Liquid metal and dross are tapped from the crucible.

Abstract: Granular ore or ore concentrate is charged into a furnace for calcining the ore at temperatures of 400 to 1050° C., the ore forming a stationary fluidized bed in the furnace. The ore is thrown onto the fluidized bed through an opening in the furnace housing disposed above the fluidized bed, the ore being accelerated by blades of a rotating impeller. The impeller is disposed outside the furnace in the vicinity of the opening of the housing. Preferably, the rotational speed of the impeller is variable, and the impeller is movable and/or pivotable with respect to the furnace.

Abstract: A method of operating mechanical separation devices at high temperatures to separate various volatile metals, metal halides and metal oxides to produce high purity materials.

Abstract: The present invention relates to a method, whereby the non-ferrous metal content of the slag generated in the production of non-ferrous metals such as copper or nickel in a suspension smelting furnace is reduced by charging metallurgical coke, with a size ranging from 1-25 mm, into the furnace. Baffles can be positioned from the roof of the furnace downwards, by means of which small particles containing copper and nickel are prevented from drifting to the back of the furnace and being tapped with the slag. The baffles force the small particles to settle in the reduction zone of the furnace.

Abstract: A method of processing flue dust, where the flue dust contains one or more compounds from a first group of zinc, lead and cadmium compounds, and contains one or more compounds from a second group of iron, silicon, calcium, magnesium and aluminum compounds, includes mixing the flue dust with a carbonaceous material, heating the flue dust/carbonaceous material mixture under non-turbulent conditions to cause a substantial portion of the compounds from the first group to become gas-borne while retaining a substantial portion of the compounds of the second group in a non-gas-borne condition, and separating the gas-borne compounds from the non-gas-borne compounds.

Abstract: A method for heating and/or melting a charge such as aluminum in a furnace using heat generated by combustion to radiatively heat the charge through a layer of protective gas wherein combustion reaction products generated by the combustion are exhausted from a lower level within the furnace, and, during melting, the protective gas layer has a higher upper boundary than during a subsequent heating period, enabling reduced NO.sub.x generation, lower fuel and oxygen consumption and reduced refractory corrosion by avoiding furnace gas flow through the high temperature upper furnace region.

Abstract: A process for treatment of zinc sulfide or other zinc bearing feed materials in conjunction with an iron sulfide containing mineral or compound to effect a separation of zinc from iron by fuming on either zinc and sulphur vapor or zinc sulphide vapor. The vapor is stripped and transported by a carrier gas from the mineral or a molten matte formed from the mineral. The process is operated at a temperature in the region of 1250.degree. to 1400.degree. C. and at a partial pressure of oxygen in the region of 10-.sup.7 to 10-.sup.11 bar. The process is conducted in the presence of a liquid matte phase which contains at least iron sulphide and which is intimately mixed in a bath with a slag phase.

Abstract: The invention relates to a method of ore beneficiation.The process comprises:(1) grinding the ore to produce a first product comprising ground ore and ground gangue,(2) separating the first product into a fraction having particles of a selected size range and a remainder,(3) separating at least a part of the remainder into a ground ore fraction and a ground gangue fraction,(4) combining the particles of selected size range from step (2) with the ground ore fraction of step (3), and(5) autogenously and/or semi-autogenously grinding the combination of step (4).The process is particularly suitable for lead and/or zinc sulphide ores.In step (5) at least 80% of the resulting ore can be ground to a particle size of less than 6 microns.

Abstract: A method of recycling hazardous and non-hazardous industrial wastes to reclaim valuable metals, metal alloys, and metal oxides, and to produce mineral wool. Wastes including hazardous wastes of USEPA Series D, F, P, K, and U are pulverized and blended with liquids such as water or wastewater to produce a homogeneous mass. Calcium from calcium-stabilized wastes is used to enhance the quality of the mineral wool, lower the sulfur content, remove phosphorous, and raise pH to facilitate metal reduction. The mass is formed into briquettes and melted in a cupola or shaft 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. Reducible metals are reduced and drawn off into molds. Substantial purity is obtained in the recovered reducible metals.

Abstract: This invention relates to the metallurgy of iron and particularly to the separation and recovery of metals from electric arc furnace (EAF) dusts. While the invention discloses a process for the separation and recovery applicable to zinc, lead, cadmium and antimony contained in such EAF dusts, the invention is particularly applicable to the separation and recovery of zinc. This invention describes a method for reducing the zinc contained in an EAF dust, volatilizing the metallic zinc so produced from the mass of the dust, and reoxidizing the metallic zinc to zinc oxide along with the simultaneous regeneration of hydrogen which can be recycled to treat additional EAF dust.