Abstract: A polarization rotator includes a bus waveguide disposed on a first layer having a longitudinal axis, a first end, and a second end, and a first upper waveguide and a second upper waveguide disposed on a second layer, above the first layer, the first upper waveguide and the second upper waveguide widening as the first upper waveguide and the second upper waveguide extend from the first end to the second end. The first upper waveguide and the second upper waveguide may also symmetrically bend toward each other and then away from each other proximate the second end.

Abstract: The invention includes a method for treating a spent catalyst containing at least one refractory mineral oxide, one or more metals in the form of sulfide(s) chosen from the following metals: molybdenum, nickel, cobalt, tungsten, vanadium, and carbon compounds, the method comprising: a) in a smelting furnace preparing a melt of cast iron with a layer of slag; b) introducing into the furnace said spent catalyst and placing it in contact with the slag and the melt of cast iron, while maintaining the furnace in rotation and while injecting an oxidizing gas containing oxygen, above the mixture, to cause the combustion of the carbon and/or sulfur compounds; c) extracting from the furnace by sequential castings the slag formed in step b) to recover a cast iron melt enriched with metal or metals, and recover a slag containing the components of the catalyst other than metals, with the exception of vanadium.

Abstract: The present invention proposes a method for feeding hot gas to a shaft furnace (12), wherein the method comprises feeding a first portion (32) of a first gas flow (24) to a mixing chamber (36) and feeding a second portion (34) of the first gas flow (24) into said shaft furnace. The method further comprises feeding a second gas flow (28) to the mixing chamber (36), allowing the first portion (32) of the first gas flow (24) to mix with the second gas flow (28) in the mixing chamber (36), thereby forming a third gas flow (38), and feeding the third gas flow (38) to the shaft furnace (12). The first gas flow (24) has a first volumetric fluid flow rate (V1), a first temperature (T1) and a first pressure (p1); the second gas flow (28) has a second volumetric fluid flow rate (V2), a second temperature (T2) and a second pressure (p2); and the third gas flow (38) has a third volumetric fluid flow rate (V3), a third temperature (T3) and a third pressure (p3).

Abstract: A method for operating a blast furnace and a corresponding blast furnace, the method including recovering top gas from the blast furnace, submitting at least a portion of the top gas to a recycling process, and feeding the recycled top gas back into the blast furnace, where the recycling process includes feeding the recovered top gas to a reformer unit, feeding volatile carbon containing material to the reformer unit, proceeding to flash gasification of the volatile carbon containing material in the reformer unit, at a temperature between 1100 and 1300° C., and thereby producing devolatized carbonaceous material and synthesis gas, and allowing the devolatized carbonaceous material and synthesis gas to react with the recovered top gas.

Abstract: “A method for producing direct reduced iron in a vertical reactor having an upper reducing zone and a lower cooling zone, the method including: feeding iron oxide feed material to an upper portion of the vertical reactor, the iron oxide feed material forming a burden flowing by gravity to a material outlet portion in a lower portion of the vertical reactor; feeding hot reducing gas to a lower portion of the reducing zone of the vertical reactor, the hot reducing gas flowing in a counter flow to the burden towards a gas outlet port in the upper portion of the vertical reactor; recovering direct reduced iron at the lower portion of the vertical reactor; recovering top gas at the upper portion of the vertical reactor; submitting at least a portion of the recovered top gas to a recycling process; and feeding the recycled top gas back into the vertical reactor, where the recycling process includes heating the recovered top gas in a preheating unit before feeding it to a reformer unit; feeding volatile carbon cont

Abstract: The present invention describes a method for treating residues comprising zinc ferrites and non-ferrous metals selected from among the group made up of lead (Pb), silver (Ag), indium (In), germanium (Ge) and gallium (Ga) or mixtures thereof in the form of oxides and sulfates, comprising the following steps: roasting of the residues in an oxidizing medium at elevated temperature in order to obtain a desulfurized residue, carburizing reduction/smelting of the desulfurized residue in a reducing medium, liquid phase extraction of carburized melt and slag, vapor phase extraction of the non-ferrous metals, followed by oxidation and recovery thereof in solid form.

Abstract: The present invention proposes a method for feeding hot gas to a shaft furnace (12), wherein the method comprises feeding a first portion (32) of a first gas flow (24) to a mixing chamber (36) and feeding a second portion (34) of the first gas flow (24) into said shaft furnace. The method further comprises feeding a second gas flow (28) to the mixing chamber (36), allowing the first portion (32) of the first gas flow (24) to mix with the second gas flow (28) in the mixing chamber (36), thereby forming a third gas flow (38), and feeding the third gas flow (38) to the shaft furnace (12). The first gas flow (24) has a first volumetric fluid flow rate (V1), a first temperature (T1) and a first pressure (p1); the second gas flow (28) has a second volumetric fluid flow rate (V2), a second temperature (T2) and a second pressure (p2); and the third gas flow (38) has a third volumetric fluid flow rate (V3), a third temperature (T3) and a third pressure (p3).

Abstract: A process for recovering non-ferrous metals, in particular copper, nickel and cobalt, from metallurgical residues containing these non-ferrous metals at an oxidation state of greater than or equal to zero, in an alternating current type plasma arc electric furnace comprising a plurality of electrodes, containing a liquid copper heel covered by a fluid slag comprising at least one fusion-reduction phase, comprising charging of metallurgical residues comprising the non-ferrous metals onto the heel contained in the plasma arc electric furnace, fusion of the metallurgical residues in the fluid slag or at the slag-metal bath interface, reduction of at least the non-ferrous metals to oxidation state zero, and intense stirring of the copper heel by injection of inert gas, preferably nitrogen and/or argon, so as to avoid crust formation and to accelerate the reduction reaction and to cause the copper-miscible non-ferrous metals to pass into the copper heel.

Abstract: The present invention relates to a method for removing halides, in particular chlorides and fluorides, from starting secondary zinc oxides, for example Waelz or Primus oxides, comprising the steps (1) for washing the secondary zinc oxides with sodium carbonate and separating the solid residue from the basic liquid, (2) leaching at least one portion of the solid residue of step 1 by means of H2SO4, preferably up to a pH between 2.5 and 4, and separating the solid residue from the acid liquid, and (3) treating the liquid from step 2 by adding Al3+ and PO43? ions and a neutralizing agent in order to remove the residual fluoride, preferably at a pH<4, and separating the liquid from the solid residue containing fluorides.

Abstract: A method for operating a blast furnace and a corresponding blast furnace, the method including recovering top gas from the blast furnace, submitting at least a portion of the top gas to a recycling process, and feeding the recycled top gas back into the blast furnace, where the recycling process includes feeding the recovered top gas to a reformer unit, feeding volatile carbon containing material to the reformer unit, proceeding to flash gasification of the volatile carbon containing material in the reformer unit, at a temperature between 1100 and 1300° C., and thereby producing devolatised carbonaceous material and synthesis, and allowing the devolatised carbonaceous material and synthesis gas to react with the recovered top gas.

Abstract: Disclosed is a process and apparatus for the treatment of divided metal residues contaminated by one or more organic compounds, including mixing, inside a chamber, of metal residues with at least one calcium/magnesium compound capable of reacting exothermically with water; exothermic reaction of the at least one calcium/magnesium compound with the water that the metal residues contain; rise in temperature of the metal residues subject to an exothermic reaction; dehydration of the metal residues during this exothermic reaction; oxidation of the organic compounds during the mixing, by bringing the metal residues contaminated by one or more organic compounds mixed with the at least one calcium/magnesium compound into contact with a gas stream containing at least partly oxygen; and removal from the chamber of a handleable dehydrated treated product having a residual content of organic compounds of less than 1% by weight of the treated product.

Abstract: The invention describes a method for recovering molybdenum, nickel, cobalt or their mixtures from used or regenerated catalysts in an electric arc furnace containing a heel of liquid cast iron, surmounted with a fluid slag, comprising the following steps: a) adding used or regenerated catalysts into the heel contained in the electric arc furnace, b) adding dosed lime in order to obtain a slag with a CaO to Al2O3 ratio comprised between 0.7 and 1.3, c) mixing the heel by injecting gas so as to avoid formation of crusts, d) melting the used or regenerated catalysts in the electric arc furnace in order to obtain a liquid ferro-alloy.

Abstract: The invention concerns a method for treating iron-and-steel plant sludge comprising adjusting the available CaO content of the sludge so as to obtain an available CaO content of 3% to 8% based on the sludge weight, adding a carbon-containing fuel, introducing the sludge onto one of the upper stages of a multistage furnace, heating the multistage furnace, gradually transferring the sludge onto the lower stages, and adjusting the temperature of the exhaust gases of the multistage furnace to at least 500.degree. C. and that of the treated sludge at the output of the multistage furnace to a temperature ranging between 700.degree. C. and 800.degree. C.

Abstract: A process for recovering non-ferrous metals, in particular copper, nickel and cobalt, from metallurgical residues containing these non-ferrous metals at an oxidation state of greater than or equal to zero, in an alternating current type plasma arc electric furnace comprising a plurality of electrodes, containing a liquid copper heel covered by a fluid slag comprising at least one fusion-reduction phase, comprising charging of metallurgical residues comprising the non-ferrous metals onto the heel contained in the plasma arc electric furnace, fusion of the metallurgical residues in the fluid slag or at the slag-metal bath interface, reduction of at least the non-ferrous metals to oxidation state zero, and intense stirring of the copper heel by injection of inert gas, preferably nitrogen and/or argon, so as to avoid crust formation and to accelerate the reduction reaction and to cause the copper-miscible non-ferrous metals to pass into the copper heel.

Abstract: The present invention describes a method for treating residues comprising zinc ferrites and non-ferrous metals selected from among the group made up of lead (Pb), silver (Ag), indium (In), germanium (Ge) and gallium (Ga) or mixtures thereof in the form of oxides and sulfates, comprising the following steps: roasting of the residues in an oxidising medium at elevated temperature in order to obtain a desulfurised residue, carburising reduction/smelting of the desulfurised residue in a reducing medium, liquid phase extraction of carburised melt and slag, vapour phase extraction of the non-ferrous metals, followed by oxidation and recovery thereof in solid form.

Abstract: The invention describes a method for recovering molybdenum, nickel, cobalt or their mixtures from used or regenerated catalysts in an electric arc furnace containing a heel of liquid cast iron, surmounted with a fluid slag, comprising the following steps: a) adding used or regenerated catalysts into the heel contained in the electric arc furnace, b) adding dosed lime in order to obtain a slag with a CaO to Al2O3ratio comprised between 0.7 and 1.3, c) mixing the heel by injecting gas so as to avoid formation of crusts, d) melting the used or regenerated catalysts in the electric arc furnace in order to obtain a liquid ferro-alloy.

Abstract: Process and apparatus for the treatment of divided metal residues contaminated by one or more organic compounds, comprising: mixing, inside a chamber, of said metal residues with at least one calcium/magnesium compound capable of reacting exothermically with water; exothermic reaction of said at least one calcium/magnesium compound with the water that the metal residues contain; rise in temperature of the metal residues subject to an exothermic reaction; dehydration of said metal residues during this exothermic reaction; oxidation of the organic compounds during said mixing, by bringing the metal residues contaminated by one or more organic compounds mixed with said at least one calcium/magnesium compound into contact with a gas stream containing at least partly oxygen; and removal from the chamber of a handleable dehydrated treated product having a residual content of organic compounds of less than 1% by weight of said treated product.

Abstract: An electric arc furnace (10) has an outer shell (12) and an inner refractory lining (24). During its operation the electric arc furnace (10) contains a bath (28) of molten metal which has a minimum and a maximum operational level (32). An inner cooling ring (23) of copper slabs (20), which are in thermo-conductive contact with the inner refractory lining (24) and equipped with spray cooling means (22), is mounted to the outer shell (12) in the region (34) between the minimum and the maximum operational level (32).

Abstract: The invention concerns a method for treating iron-and-steel plant sludge comprising adjusting the available CaO content of the sludge so as to obtain an available CaO content of 3% to 8% based on the sludge weight, adding a carbon-containing fuel, introducing the sludge onto one of the upperstages of a multistage furnace, heating the multistage furnace, gradually transferring the sludge onto the lower stages, and adjusting the temperature of the exhaust gases of the multistage furnace to at least 500° C. and that of the treated sludge at the output of the multistage furnace to a temperature ranging between 700° C. and 800° C.

Abstract: A process for producing liquid smelting iron in an electric arc furnace includes several electrodes, equipped with a hearth, and containing a heel covered with a non-foaming liquid slag. The process further includes the reduction of the metallic fines, in order to form pre-reduced metallic fines containing an excess of free carbon; the hot transfer of the pre-reduced metallic fines within a curtain of inert gas into the heel contained in the electric arc furnace; the agitation of the heel by the injection of gas in such a manner that the formation of crusts is avoided; and the smelting of the pre-reduced metallic fines in the electric arc furnace in order to obtain the liquid smelting iron.