Abstract: A method for the pyrometallurgical processing of a sulphide material containing copper, the sulphide containing relatively high quantities of silica and relatively low quantities of iron, wherein the process comprises feeding the sulphide material to a TSL furnace operated under oxidising conditions such that the sulphide material forms blister copper containing between 1.2 and 1.5 wt % sulphur and a slag containing between 7 and 13 wt % copper.

Abstract: A railcar body comprises at least one panel assembly having a first panel and a second panel, both extending longitudinally along the railcar body and adjacently to each other. The inner wall of the first and second panels, which are longer than their outer wall, respectively have at least a first and a second mating interface which are different from each other and compatible so as to be located at a predetermined distance from each other, thereby creating a gap of a predetermined width between two juxtaposed edges of the panels. This panel assembly is designed to be compatible with a laser welding process.

Abstract: A method for recycling a material may include carrying out a first pass operation. The first pass operation may include preparing an E-waste material and a solid oxide material. The E-waste material may include Fe and Si. The first pass operation may include blending the E-waste material with fluxing agents. The first pass operation may include feeding a furnace with the blended E-waste material and the solid oxide material. The method may include smelting the blended E-waste material and the solid oxide material from the first pass operation to obtain a slag. The slag may include iron oxide and a molten metal. The molten metal may include copper.

Abstract: The invention relates to a method of using a suspension smelting furnace and to a suspension smelting furnace and to a concentrate burner (4). The concentrate burner (4) comprises a first gas supply device (12) for feeding a first gas (5) into the reaction shaft (2) and a second gas supply device (18) for feeding a second gas (16) into the reaction shaft (2). The first gas supply device (12) comprises a first annular discharge opening (14), which which is arranged concentrically with the mouth (8) of a feeder pipe (7), so that the first annular discharge opening (14) surrounds the feeder pipe (7). The second gas supply device (18) comprises a second annular discharge opening (17), which is arranged concentrically with the mouth (8) of the feeder pipe (7), so that the second annular discharge opening (17) surrounds the feeder pipe (7) opening (14).

Abstract: These disclosures relate to preparing nickel metal (Ni(0)) suited for use in catalyst systems, such as nickel complexes with phosphorus-containing ligands, useful to catalyze the hydrocyanation of ethylenically unsaturated compounds. The methods described herein can include use of steam during reduction of nickel.

Abstract: An improved method of reducing a mixed metal oxide composition comprising oxides of nickel, cobalt, copper and iron in a hydrogen atmosphere to produce a mixture of the respective metals, the improvement wherein the atmosphere further comprises water vapor at a concentration, temperature and time to effect selective reduction of the oxides of nickel cobalt and copper relative to the iron oxide to produce the metallic mixture having a reduced ratio of metallic iron relative to metallic nickel, cobalt and copper.

Abstract: Aspects of the present invention refer to a MHP process do produce rough ferro-nickel product and that may include the steps of mixing nickel hydroxide with an iron source and slagging agents, putting the mixture in contact with a reducing agent producing a ferronickel alloy, and producing a roasted product that has disseminated ferronickel alloy inside the structure.

Abstract: A method for producing metal oxide from a metal salt selected from nickel hydroxide, cobalt hydroxide, mixed nickel-cobalt hydroxide, nickel carbonate, cobalt carbonate or mixed nickel-cobalt carbonate includes providing a mixture of the metal salt, mixing the metal salt with a binder selected from an inorganic binder or an organic binder, forming the mixture into agglomerates, and calcining the agglomerates to produce metal oxide. Another method for making metallic nickel or cobalt includes providing the above metal salt, mixing the metal salt with the above binder to form a mixture, optionally adding water, forming the mixture into agglomerates, drying the agglomerates, adding an effective reducing amount of coke and/or coal and directly reducing the dried agglomerates with an effective amount of heat to produce metallic nickel and/or cobalt. Coke particles may be added to the mixture prior to agglomeration.

Abstract: A method of smelting a nickel intermediate product in a smelter that contains a molten bath of metal and slag to produce a nickel product, the method comprising supplying the nickel intermediate product and a solid reductant to the smelter and smelting the nickel intermediate product to produce molten nickel, and controlling the chemistry of the slag so that the slag has (a) a high solubility for elements and compounds in the nickel intermediate product that are regarded as contaminants in the nickel product and (b) a liquidus temperature in the range of 1300-1700 C.

Abstract: These disclosures relate to preparing nickel metal (Ni(0)) suited for use in catalyst systems, such as nickel complexes with phosphorus-containing ligands, useful to catalyze the hydrocyanation of ethylenically unsaturated compounds. The methods described herein can include use of steam during reduction of nickel.

Abstract: Provided is a roasting method capable of reducing both C and S components in minerals down to 0.5% or less, respectively, and securing a yield ratio of 90% or more for the Mo component. In a rotary kiln 7, a V, Mo and Ni containing material containing C and S components is subjected to oxidizing roasting to remove the C and S components from the material before reducing the material by means of a reducing agent in order to recover valuable metals composed of V, Mo and Ni. The rotary kiln is equipped with a burner 11 disposed on a material charge side 8a of the roasting furnace 8 to which the material is charged. In the roasting furnace, a direction along which the material moves and a flow of oxygen-containing gas introduced into the roasting furnace 8 are set to be parallel with each other.

Abstract: Burner assembly for use in industrial heating and melting applications of material susceptible to oxidation at elevated temperatures is comprised of a flow passage of oxidant surrounded by an annular flow passage of fuel whereby the oxidant is substantially contained inside the fuel layer up to at least 5 oxidant nozzle diameters downstream of the burner outlet in order to minimize contact between the oxidant and the furnace load.

Abstract: A method of smelting a nickel intermediate product in a smelter that contains a molten bath of metal and slag to produce a nickel product, the method comprising supplying the nickel intermediate product and a solid reductant to the smelter and smelting the nickel intermediate product to produce molten nickel, and controlling the chemistry of the slag so that the slag has (a) a high solubility for elements and compounds in the nickel intermediate product that are regarded as contaminants in the nickel product and (b) a liquidus temperature in the range of 1300-1700 C.

Abstract: A process for producing a metallic nickel product with a low iron content, that includes: (i) providing an acidic product liquor; (ii) subjecting the acidic product liquor to an ion exchange process to absorb the nickel and part of the iron; (iii) eluting the nickel and iron to produce an eluate containing the nickel and iron. (iv) neutralising the eluate to leave an iron depleted eluate; (v) neutralising the iron depleted eluate to cause precipitation of nickel hydroxide containing low iron; (vi) calcining the nickel hydroxide to convert it to nickel oxide; (vii) subjecting the nickel oxide to direct smelting in the presence of a reductant to produce a molten nickel phase; and (viii) refining the molten nickel phase by oxidation to produce a metallic nickel product with low iron content.

Abstract: An improved method of reducing a mixed metal oxide composition comprising oxides of nickel, cobalt, copper and iron in a hydrogen atmosphere to produce a mixture of the respective metals, the improvement wherein the atmosphere further comprises water vapour at a concentration, temperature and time to effect selective reduction of the oxides of nickel cobalt and copper relative to the iron oxide to produce the metallic mixture having a reduced ratio of metallic iron relative to metallic nickel, cobalt and copper.

Abstract: The invention relates to a method for reducing and/or refining a metal-containing slag. The aim of the invention is to improve reduction of the slag. For this purpose, calcium carbide (CaC2) is added to the slag as the reducing agent.

Abstract: The alpha form of nickel (II) hydroxide is formed by dissolving a compound of nickel (II), such as nickel acetate, in a water miscible dihydric alcohol (diol), such as ethylene glycol, propylene glycol and suitable oligomers, and adding a suitable base such as sodium carbonate. The ?-Ni(OH)2 precipitate is separated from the diol-based mother liquor and dried. This stable ?-Ni(OH)2 can be calcined at temperatures in the range of about 573K to about 1073K to form nanometer-size particles of NiO having, for example, fibrous shapes. And the small particles of NiO can be reduced with hydrogen to form small, fibrous nickel particles. Both the NiO particles and Ni particles have utility as catalysts and offer utility in applications requiring electronic and/or magnetic properties.

Abstract: A metallic article made of metallic constituent elements is fabricated from a mixture of nonmetallic precursor compounds of the metallic constituent elements. The mixture of nonmetallic precursor compounds is chemically reduced to produce an initial metallic material, without melting the initial metallic material. The initial metallic material is consolidated to produce a consolidated metallic article, without melting the initial metallic material and without melting the consolidated metallic article.

Abstract: Disclosed is a method for reducing metalliferous material to a reduction product. Also disclosed is an apparatus for reducing metalliferous material to a reduction product.

Abstract: An improved method of reducing a mixed metal oxide composition comprising oxides of nickel, cobalt, copper and iron in a hydrogen atmosphere to produce a mixture of the respective metals, the improvement wherein the atmosphere further comprises water vapour at a concentration, temperature and time to effect selective reduction of the oxides of nickel cobalt and copper relative to the iron oxide to produce the metallic mixture having a reduced ratio of metallic iron relative to metallic nickel, cobalt and copper.

Abstract: A process for producing Ni(CO)4 from carbon monoxide and a source of nickel selected from the group consisting of elemental nickel, a nickel compound or mixtures thereof, provided the nickel compound is not nickel chloride per se or in admixture with a nickel carbonate ore, in an amount greater than 50% W/W nickel chloride; which process comprises (a) treating the nickel source with hydrogen at a pressure of at least atmospheric pressure and an effective temperature, in the presence of chloride anion or an in situ generator thereof precursor, to produce a resultant nickel; (b) reacting the carbon monoxide with the resultant nickel to produce the Ni(CO)4; and collecting the Ni(CO)4. The process offers the production of Ni(CO)4 at atmospheric pressure and at a sufficiently high rate for direct use in subsequent deposition processes without the need for storage facilities.

Abstract: In a method for removing chromium oxide and nickel oxide, and combinations thereof, from liquid slags or slag mixtures, in which the liquid slag is A charged onto a metal bath, in particular an iron bath, and reduced by feeding carbon or carbon carriers, the carbon feed into the metal bath is effected until a decrease of the Cr and/or Ni oxide contents of the slag to a value of between 0.8 wt.-% and 0.2 wt.-%. As the pregiven Cr and/or Ni oxide content range of the slag is reached, reductants having higher reduction potentials such as, e.g., Al, Ca, Si, Fe—Si or Ca—Si are added in order to lower the Cr and/or Ni oxide contents to below 0.15 wt.-%, preferably below 0.08 wt.-%.

Abstract: A method for processing steel slags and optionally iron carriers such as, e.g., electric furnace slags, converter slags, dusts derived from steel production, mill scale or secondary metallurgical residues, in which the molten steel slags or iron carriers are supplemented with chromium ores or chromium-containing and/or nickel-containing dusts in order to adjust a slag basicity of 1.2 to 1.6, whereby the bath temperature is maintained at above 1600° C., in particular between 1650° C. and 1800° C., and a carbon-containing iron bath is provided or formed. In addition to environmentally safe slags, a high-grade ferrochromium alloy may be recovered, thus enhancing the economy of the method.

Abstract: Provided is an ultrafine nickel powder suitable for a laminated ceramic capacitor electrode material. According to the ultrafine nickel powder, cracks and/or delamination are not liable to generate in the process for producing a ceramic capacitor, and its internal electrode can be made into a thinner layer, and the electric risistivity of the capacitor can be made low. The ultrafine nickel powder has an average particle size of 0.1-1.0 &mgr;m, having the sulfur content of 0.02-1.0% by weight, and particles thereof being spherical, thereby exhibiting excellent properties. They can be produced by vapor phase hydrogen-reducing process using nickel chloride vapor.

Abstract: The present invention provide metallic nickel powder in which the occurrence of delaminatoin can be prevented by providing superior sintering propreties in production processes for multilayer ceramic capacitors and by providind superior dispersion characteristics in the forming of conductive pastes. By being brought into contact with nickel chloride gas and a reducing gas at a temperature in the range of the reduction reaction, metallic nickel power is node gas and a reducing gas at a produced in which the oxigen content is 0.1 to 2.0% by weight and there is not absortion peak at wavelengths ranging from 3600 to 3700 cm−1 in infrared spectroscopy.

Abstract: The present invention is concerned with a method for the pre-reduction of laterite fines in a reactor, preferably a fluidized bed, with reducing gases generated in situ by adding a reducing agent such as a carbonaceous material in the fluidized bed chamber, fluidizing the bed with an oxidizing gas and maintaining the reactor at a temperature sufficiently high to partially combust the coal and generate a reducing atmosphere. The reactor bed discharge calcine product has a carbon content of about 0.1%, and the composite reactor product has a carbon content lower than 2.0%.

Abstract: In a method of converting slags derived from nonferrous metallurgy, in particular primary and secondary Ni and Cu metallurgical slags, while recovering and/or enriching the nonferrous metals and forming synthetic puzzolans, the molten oxidic slags are reduced with gases containing H2 and CO such as, e.g., cracked gas in a first reduction stage above a metal bath containing Cu and/or Ni and optionally Co. The redox potential of the CO/H2 mixture is reduced by adding 10 to 40% by volume H2O vapor and/or CO2 in order to hold off the reduction of Fe oxides. Subsequently, the remaining slag free of Cu and Ni is further reduced above an iron bath while using carbon in order to reduce the portion of Fe oxides so as to produce a slag free of Fe and nonferrous heavy metals.

Abstract: Chlorine gas from a supply nozzle is mixed with the vapor of nickel chloride and the mixed gas is supplied from a supply nozzle into a hydrogen gas atmosphere in a reduction reactor at a reduction temperature of 900 to 1100° C. The volume of chlorine gas to be mixed versus the vapor of nickel chloride is adjusted to a ratio of 0.01 to 0.5 moles per mole of the vapor of nickel chloride. The particle size of the nickel powder can be controlled appropriately, and also, uniformity of particle size, smoothability of surfaces of particles, and sphericity can be improved.

Abstract: A method for producing solid metal product is disclosed including the steps of providing carbon and metal bearing compounds in compacts, coating the compacts with treatment materials, encapsulating the compacts with carbonaceous containing materials to form a residual layer, and treating the residual layer before introduction of the compacts into a furnace. The compacts contain carbon containing metal bearing compounds, and are coated with mixtures of carbonaceous materials dispersed within a binder material such as a viscous liquid, molasses, alcohol, or fuel oil. The coated compacts are treated to form a hardened outer residual layer. The outer residual layer provides for a sacrificial outer coating on the compacts that reacts with any oxidizing gaseous components within the furnace, while the carbon containing metal bearing compounds within the compacts are heated and metallized inside the compounds.

Abstract: Besides a synthesis gas, a metallurgical raw material is to be produced from an oil containing heavy metals. To do this, the oil is partially oxidized and the heavy metal-containing soot is separated and burnt and the heavy metals thus occurring as ash can be taken to further processing, e.g. washing from the synthesis gas produced, using an aqueous washing solution.

Abstract: A method for working up refuse or metal-oxide-containing refuse incineration residues or metallurgical residues includes an at least partial oxidation in a meltdown oxidizing reactor followed by a two-stage reduction. The first reduction stage is effected in an iron bath reactor in which iron oxides are not yet reduced. In the second reduction stage also iron oxides are reduced in an iron bath calciner, a pig iron bath being obtained. The metal bath discharged from the iron bath reactor reaches a segregation mold, from which crude bronze can be drawn off.

Abstract: A pyrometallurgical vessel suitable for continuous or semicontinuous smelting and/or conversion of molten base metal sulfide feed materials. The top blown, bottom stirred vessel includes oxidizing gas lances and feed pipes directing their respective contents directly or indirectly into bath eyes opened up in the molten bath by gas injected through porous plugs disposed at the base of the vessel. Low space velocities in the vessel result in reduced dusting.

Abstract: A method of recovering metals and producing a secondary slag from base metal smelter slag produced by a copper or nickel smelter includes mixing the smelter slag with at least one reducing agent selected from the group consisting of carbon and aluminum, said carbon (if present) being from about 1% to about 10% by weight of the slag and said aluminum (if present) being from about 5 to about 30% by weight of the slag, and with from zero to about 60% calcium oxide by weight of the slag. The mixture is heated above the eutectic melting point thereof directly and to ignition temperature aluminothermically (if aluminum is present as reducing agent) to reduce the iron silicate to ferrosilicon containing substantially all the copper, nickel and cobalt which was in the smelter slag and form a secondary slag comprising at least one compound selected from the group consisting of calcium silicate, calcium aluminate and calcium iron aluminum silicate. The ferrosilicon is then separated from the secondary slag.

Abstract: Copper and or nickel sulfide ore concentrates of high intrinsic value are oxygen smelted by introducing such concentrates via feeds (32) into a closed loop extraction circuit in which a molten sulphide carrier composition is forcibly circulated by an R-H unit (14) through lower hearth (10) at which feed of the concentrates takes place, and upper hearth (12) at which controlled oxidation with technically pure oxygen through top lances (4) takes place to oxidize copper sulphide and iron sulphide in the concentrate to iron oxide. Copper is removed via line (42). Slag containing iron oxide is discharged via weir (22) into a secondary circuit in hearths (24 and 28). Carbonaceous reductant added to the slag in (28) reduces the iron oxide in the slag to hot iron product.

Abstract: The invention relates to a method and an apparatus for the suspension smelting of suifidic, finely divided raw materials containing metals, such as copper, nickel and lead, by using oxygen enrichment. In this method into the suspension smelting furnace (1) there is fed the raw material (4,5) to be smelted together with flux (6) and oxidizing gas (7) and the walls (18) of the reaction space of the suspension smelting furnace are cooled and at least two molten phases created (16,17). According to the invention the degree of oxygen enrichment of the oxidizing gas is at least 40% in order to raise the temperature of the particles in suspension to at least 200.degree. C.

Abstract: An improved method and apparatus for forming metallized iron by direct reduction of particulate iron oxide is disclosed. Spent reducing gas is recycled from the reduction furnace through a cooler-scrubber and a catalyst-containing stoichiometric gas reformer. Upon removing the process gas from the cooler-scrubber, it is contacted with a chlorine dioxide spray, then compressed and cooled, the sulfur compound removed, and the process gas recycled either into the furnace cooling zone, or directly into the reformer, or divided and directed into both uses. Thus, most of the sulfur containing components of the spent reducing gas are removed, thereby reducing the sulfur contamination of the gas reformer catalyst. Reducing sulfur contamination of the gas reformer catalyst improves the overall efficiency of the direct reduction process. Either high sulfur ores, or high sulfur process gas, or both can be utilized in the invented process.

Abstract: A method for oxidizing the pulverous fuel of a furnace, advantageously a flash smelting furnace, by means of a burner, so that the oxidation takes place mainly owing to an effective mixing of two different combustion gases, pulverous fuel and possibly an extra fuel, in the furnace space. The combustion gases are conducted into the furnace space in separate jet flows, so that oxygen is fed in through the center in an at least partly turbulent flow, and the air is fed around it in several separate flows. A burner for mixing pulverous fuel and combustion gas and for burning them in the furnace space is described.

Abstract: The invention relates to a method for fully beneficating nickel sulfide concentrates or other corresponding mixtures, unsuitable for smelting, by combining the use of both pyrometallurgical and hydrometallurgical processes, so that there are formed two separate concentrates, the first of which is suited to pyrometallurgical and the second to hydrometallurgical treatment. In the concentrate going to pyrometallurgical processing, the valuable metal content increases as a consequence of the treatment, and the Fe/MgO ratio of this concentrate is at least 2.6.

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: An improved method and apparatus for forming metallized iron by direct reduction of particulate iron oxide is disclosed. Spent reducing gas is recycled from the reduction furnace through a cooler-scrubber and a catalyst-containing stoichiometric gas reformer. Upon removing the process gas from the cooler-scrubber, it is contacted with a chlorine dioxide spray, then compressed and cooled, the sulfur compound removed, and the process gas recycled either into the furnace cooling zone, or directly into the reformer, or divided and directed into both uses. Thus, most of the sulfur containing components of the spent reducing gas are removed, thereby reducing the sulfur contamination of the gas reformer catalyst. Reducing sulfur contamination of the gas reformer catalyst improves the overall efficiency of the direct reduction process.

Abstract: An apparatus for improving mass transfer in a multiple hearth furnace has a plurality of risers adjacent the furnace center shaft which are in fluid communication with a source of treatment fluid. The risers have radially extending branch pipes, each pipe having a plurality of downcomers corresponding to the rabbles on an adjacent rabble arm. The downcomers have outlets or nozzles at their distal ends and they are preferably located adjacent a rear face of the rabble, near a trailing edge. In operation, as the rabbles plough over the material on the furnace hearth, the downcomers inject a treatment fluid, such as steam or reducing gas, into the material at the point of stirring. This ensures full exposure of the material to the treatment fluid. A second embodiment places the outlets beneath the top surface of the material to be treated. A method for mass transfer on a rotary hearth furnace is also disclosed.

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: This invention relates to a thermal upgrading process whereby nickel-containing limonite or limonite/saprolite blends are pelletized with requisite amounts of solid carbon reductant and a sulfure-bearing concentrating agent. The pellets are fed to a reactor where they are gradually heated, causing reduction of the metal values. The reduced pellets are then held in a "metallics growth zone" of the reactor at a temperature high enough to allow for liquid-phase migration of the metallics within the pellets but below the point at which the pellets become sticky. The metallics growth zone is provided with a carefully controlled combustion gas atmosphere equivalent to about 60-65% aeration of partial combustion of natural gas which prevents further reduction or re-oxidation and thus provides a good environment for metallic particle growth. After a sufficient retention time, the pellets are then rapidly cooled to prevent the disproportionation of wustite to magnetite.

Abstract: A method for smelting reduction of Ni ore comprises charging Ni ore and carbonaceous material into a converter type smelting reduction furnace having bottom-blow tuyeres and a top-blow lance, the smelting reduction furnace holding a molten metal, blowing oxygen gas from the top-blow lance and a stirring gas from the bottom-blow tuyeres into the furnace, and discharging slag so that a relation represented with a formulaVo>0.4 Ws+1.0can be satisfied, Vo (m.sup.3 per ton of molten metal) being a specific volume of the smelting reduction furnace per ton of molten metal and Ws (ton per ton of molten metal) being 2 specific weight of slag per ton of molten metal.

Abstract: A method for smelting reduction of Ni ore comprises charging Ni ore, carbonaceous material and flux into a converter type smelting reduction furnace holding molten iron therein and controlling a post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] inside the smelting reduction furnace at 0.3 or more by blowing oxygen from a top-blow oxygen lance and stirring gas from a bottom-blow tuyere arranged in the bottom of the smelting reduction furnace into the smelting reduction furnace.A relation between a content of carbon [C] (%) in molten metal and an amount of slag produced per ton of molten metal is represented with a formula:[C].gtoreq.

Abstract: A method and apparatus for producing, in a reactor, a suitable prereduced product for final reduction from material containing metal oxide. The material is preheated in a fluidized bed by means of hot gases from a subsequent prereduction stage. The hot material is smelted and prereduced in a flame chamber utilizing hot reducing gases from a subsequent final reduction stage. The prereduced material is completely reduced in the final reduction stage.

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.