Abstract: An exhaust gas treatment method includes: burning a combustible component in exhaust gas by causing the exhaust gas, which is produced in an electric furnace, to flow into a slag holding furnace and supplying oxygen-containing gas into the slag holding furnace; causing the burned exhaust gas to flow from the slag holding furnace to a suction device through an exhaust gas pipe; adjusting an internal pressure of the electric furnace by introducing external air into the exhaust gas pipe through an opening portion provided in the middle of the exhaust gas pipe; and changing an area of the opening portion depending on a variation in the internal pressure of the electric furnace by using an opening area changing unit provided in the opening portion.

Abstract: The present invention relates to a method of operating an electric arc furnace containing (a) a furnace shell having a tapping hole and/or a slag door, (b) a furnace roof having a plurality of electrodes provided so as to face downwards, and (c) a rotating apparatus that rotates the furnace shell around a vertical axis relative to the electrodes, the method contains a rotating step of rotating the furnace shell relative to the electrodes during melting of a metal material, and a holding step of stopping the rotation when any one of the plurality of electrodes reaches a holding position that is previously set close to the tapping hole or the slag door, and holding the furnace shell at the holding position.

Abstract: A method for supplying energy to a scrap metal pile (9) in an electric arc furnace (2). Energy is supplied by jets of hot gas in a first phase. Energy is supplied by electric arcs in a second phase after the first phase is completed. Hot gas is supplied via at least six jets. A device (1) for the method has an electric arc furnace (2), one or more blowing devices (6a, 6b, 6c), supply jets of reactant hot air into the chamber (7) of the electric arc furnace (8). The devices have a total of at least six nozzles (10a, 10b, 10c, 10d, 10e, 10f) with nozzle openings. Fuel conducting devices (8) supply fuel to the jets of reactant hot air.

Abstract: Provided are a fixed-type electric furnace enabling continuous operation which allows melting without the interruption of power supply and tapping in a fixed state, and a fixed-type electric furnace and a molten steel production method using same. The fixed-type electric furnace comprises: a preheating furnace which is disposed on the side of a melting furnace and preheats an iron source (scrap) using exhaust gas from the melting furnace; a supply means for supplying the iron source, which has been preheated in the preheating furnace, to the melting furnace; the melting furnace comprising electrodes for melting the preheated iron source; and a fixed-type discharge means for discharging molten steel which has been melted in the melting furnace, wherein the preheating furnace is integrally connected to the melting furnace.

Abstract: The present invention provides a shaft high temperature continuous graphitizing furnace comprising a furnace body comprising a feeding inlet and a discharging outlet, an electrode pair, a cooling system and a discharging device; the furnace body is designed to be a shaft cylindrical structure; the electrode pair is provided within the furnace body and comprise an upper electrode and a lower electrode, the upper electrode is located below the feeding inlet, and an umbrella or cone table shape electric field having a lower cross section area greater than its upper cross section area arises between the upper electrode and eh lower electrode; and the cooling system is located between the lower electrode and the discharging outlet.

Abstract: A burner insert for an arc furnace has a support frame which can be inserted into a wall opening of a side wall of the arc furnace and a burner arranged in the support frame. The support frame is pivotably mounted around a pivot axis relative to the side wall between a park position and an operating position in the installed state of the burner insert. In the park position, the support frame and burner are located outside and, in the operating position, at least partially inside an inner chamber of the arc furnace.

Abstract: A vitreous silica crucible manufacturing apparatus includes a plurality of carbon electrodes configured to heat and melt raw material powder by arc discharge, and a value of a ratio R2/R1 of a diameter R2 of a front end of each of the carbon electrodes to a diameter R1 of a base end is set in a range of 0.6 to 0.8. Each carbon electrode has a diameter reduction portion formed at a front end position and reduced in diameter from a diameter R3 of a base end side to the diameter R2 of the front end. When a length of the diameter reduction portion is L1, the diameter of the front end is R2, the diameter of the base end is R1, an angle between the axis lines of the carbon electrodes is ?1, and X=(R1?R2)/2, a value of L1?(X/tan(?1/2)) is set in a range of 50 to 150 mm.

Abstract: An electrostatic levitation furnace wherein main electrodes opposed to each other within a vacuum chamber are arranged at intervals to form interspaces between them. Auxiliary electrodes are arranged to correspond to each of the electrostatic field generating interspaces, and laser irradiators are arranged above the uppermost main electrode and under the lowermost main electrode, and the main electrode positioned midway between the uppermost and lowest one has a through-hole on an optical path of laser beam which a sample can be passed through. When two species of samples are fused together, regardless of whether or not the samples are conductors, the furnace has the function of melting the levitated samples and fusing them together while maintaining each of the temperatures of the samples, and consequently this permits realization of fusion in a state free of external interference.

Abstract: An electrostatic levitation furnace is improved by providing three pairs of electrodes opposed to each other respectively on three axes perpendicularly intercepting each other at a position where the sample is to be levitated in the vacuum chamber, and disposing a plurality of access ports, which are directed to the position of the sample, to the vacuum chamber tree-dimensionally, whereby the accessible direction against the sample is diversified, it becomes possible to improve the degree of freedom in distribution of various apparatuses and easily cope with increase of apparatuses.

Abstract: A metal mounting assembly for mounting a burner or lance in a furnace has a water-cooled main body securable in an aperture in a furnace wall, a series of cooling fins extending from the main body so as to project into the furnace when secured thereto, and at least one mounting tube extending through the main body for mounting a burner or lance therein.

Abstract: An electric arc furnace and method for forming tubular carbon nanostructures comprising a first electrode (cathode) and an a second electrode (anode) opposite the first electrode, sources of voltage (V) and current (A) to create charged particles (Ie) and produce an arch between the electrodes, a source of a gas to surround the arc, and a source of carbon precursor positioned adjacent the anode and within the arc, wherein the arc is maintained at a pressure and high temperature for a time sufficient to heat the carbon precursor to form carbon nonotubes upon the anode.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: An electrode assembly comprising concentric tubular electrodes is provided for high temperature processing of materials. The electrode assembly is connected with a power supply that includes switching means for alternatively operating the electrode assembly in a transferred mode of operation, in a non-transferred mode of operation, or according to a controlled sequence of non-transferred and transferred modes of operation. The power supply system includes variable inductors, such as leakage-coupled reactors, for controlling the electrical power supplied to the electrodes for producing a DC arc. The electrode assembly can be incorporated into an arc furnace for processing waste material in the furnace. The electrode assembly is also suitable for use in the practice of in-situ vitrification and remediation of contaminated soil.

Abstract: An electric arc furnace (1), wherein solids are injected into the furnace chamber. The lances (9, 10, 11) are guided through the wall (12) of the electric arc furnace (1) and inserted into the wall of the furnace, whereby at least one lance is associated with each electrode (2, 3, 4), in order to enable a homogenous formation of slag and to inject as great an amount of solids as possible. The lances are distributed in an approximately uniform manner along the periphery of the furnace. The inclination of the lances and thus the angle of injection are selected in such a way that they form an angle of approximately 30-80° in relation to the flow direction of the melting bath and form an angle of approximately 10-30° in relation to the horizontal.

Abstract: In order to operate an electric arc furnace (1) in optimum conditions, especially in order to build up and maintain a certain intensity of foamed slag, the amount of slag builder fed into the furnace (1) and therefore the power consumption of the furnace (1) is regulated according to the current received by the electrodes (2) in such a way that a maximum amount of slag builder is initially added in order to build up said foamed slag until the amount of current received by the electrodes (2) is reduced. Subsequently, the amount of added slag builder is reduced until the amount of current received reaches a predetermined set value. The theoretical amount of current received is kept constant by reducing or increasing the added amount of slag builder.

Abstract: A mounting block and an improved mounting arrangement for apparatus used in metal melting, refining and processing, particularly those apparatus adapted to steel making in an electric arc furnace, such as burners, lances and the like with supersonic oxygen lancing capability. The mounting block is fluid cooled to survive the hostile environment of the electric arc furnace and is designed to rest on the step between the side wall and hearth of the furnace without any substantial change to the structure of the furnace. The mounting block comprises a plurality of fluid cooling conduits surrounding an aperture which is formed through the block and adapted to mount the apparatus. The mounting arrangement includes utilizing the mounting block to mount an apparatus with supersonic oxidizing gas or lancing capability in an electric arc furnace. The apparatus is mounted by passing it through an aperture in a water cooled side panel aligned with the mounting aperture in the mounting block.

Abstract: Aspiration system to reduce the losses of fine materials and powders from an electric arc furnace having a lower hearth suitable to contain the bath of metal material being melted, a substantially cylindrical chamber arranged above the hearth, at least one electrode arranged in a central zone of the chamber and a roof arranged to cover the chamber and provided with at least one aperture through which the fumes produced by the bath can exit, the system comprising a first aspiration sub-system arranged inside the chamber and at least another discharge sub-system arranged in correspondence with the roof, the first aspiration sub-system comprising a coil of cooling pipes arranged helical so as to define, in a vertical direction, empty zones between the spirals of pipes, the coil of cooling pipes being distanced from the cylindrical wall of the chamber to define a peripheral interspace through which the fumes can ascend towards the roof according to at least an ascensional, rotatory vortex.

Abstract: An arc furnace fume collection system has a plurality of duct lines leading to a common duct that leads to a baghouse for filtering dust. The supplemental duct lines have high pressure fans, blowers, or compressors and join one of the other duct lines through a nozzle. The nozzle connection acts as a venturi to supplement the pulling power of a common exhaust fan downstream of the baghouse filter.

Abstract: Provided is a process for melting a charge in a furnace. Energy of fusion is supplied to the charge, and gases including at least one combustible gas are generated during the the melting. A post-combustion of the combustible gas is performed by injecting an oxidant gas containing more than 25% by volume of oxygen during at least some periods of the process. The oxidant gas is injected above the charge, in the form of at least one oxidant gas jet. Each jet has a flow rate of between approximately 50 and 1200 Sm.sup.3 /h and a speed of injection into the furnace of between approximately 5 m/s and 150 m/s. The process has particular applicability to an electrical furnace for melting scrap for the production of steel.

Abstract: A melting furnace for the thermal treatment of special waste materials containing heavy metal and dioxin is provided. The melting furnace includes a main furnace vessel, the main furnace vessel having a melting end for receiving a melt, and a gas chamber above the melt. The melting furnace further includes at least one charging device for supplying a product to be treated, at least one gas outlet, and at least one discharge chamber, the at least one discharge chamber being separated from the main furnace vessel by a separating wall and being connected to the melting end by a siphon, the at least one discharge chamber having a gas chamber above the melt. At least one first heater projects into an interior of the main furnace vessel, and at least one second heater is provided in the at least one discharge chamber.

Abstract: Fume intake and cooling device for intake conduits (11,111,211) in electric arc furnaces (26a,26b), comprising a containing structure (28) associated at one end (12) with an aperture on the roof of the furnace and connected at the second end (13) with an intake and filter system (27), the containing structure (28) having, in cooperation with its inner sidewalls, cooling means, the cooling means comprising a pipe (14), which is spiral shaped and has turns (16) lying on a plane substantially at right angles to the longitudinal axis of the conduits (11,111,211), the turns (16) being distanced with respect to each other in such a way as to form interstices (20) between adjacent turns (16), the interstices (20) through which the fumes pass serving to anchor the slag.

Abstract: A charge of scrap is melted in a furnace (1) with post-combustion of the fumes by injection of an oxygenated gas into the space in the furnace above the charge. During periods of post-combustion, the oxygenated gas is injected in the form of several jets each having a flow rate comprised between about 400 and 1200 Nm.sup.3 /h and an injector (11, 12) outlet speed comprised between about 50 and 150 m/s, preferably between about 500 and 900 Nm.sup.3 /h and between about 70 and 125 m/s. Several groups of injectors (11, 12) are used, having an outlet tangential component relative to the vertical axis (X--X) of the furnace (1), successive groups of injectors being disposed at different levels (N.sub.1, N.sub.2) and oriented in alternate circumferential directions.

Abstract: Melting method for an electric arc furnace with alternative sources of energy for the melting of iron-based alloys, the electric furnace (10) including tuyeres (13) positioned on the bottom to deliver oxygen, at least one tuyere (15) to deliver coal dust which works in the area of contact between the bath of molten metal (16) and the layer of slag (22), at least one supersonic lance (12) cooperating with a lance (29) to deliver coal dust, these lances (12, 29) having a working position (12c, 29c) in which the supersonic lance (12) is positioned in close proximity to the surface of the molten metal (16) and the lance (29) to deliver coal dust is positioned in the vicinity of the surface of the layer of slag (22), and a plurality of burners (28) positioned on the cooled sidewalls (31) of the furnace (10) and delivering oxygen-based gases and combustible substances, whereby at least two first burners (28) work with the action of one burner supporting the action of the next one, the furnace (10) being charged wit

Abstract: A waste-melting furnace includes a furnace body, a rotary heat-resistive vessel which is arranged inside the furnace body and into which waste is to be fed, and a transferred arc type torch plasma gun and a water-cooled electrode arranged above the rotary heat-resistive vessel, the plasma gun and electrode being opposed to each other.

Abstract: There is disclosed an electric arc furnace for the production of steel by melting scrap, in particular iron scrap, and/or sponge iron and/or pig iron as well as fluxes in a furnace vessel, into which at least one graphite electrode projects, which is displaceable in its longitudinal direction, wherein an electric arc is ignited between the graphite electrode and the charging stock. To achieve a particularly high energy input, the graphite electrode projects into a lower part of the furnace vessel from aside and the lower part, in the region of the graphite electrode, has an enlargement radially protruding outwardly relative to the upper part.

Abstract: There is disclosed an electric arc furnace for the production of steel by melting scrap, in particular iron scrap, and/or sponge iron and/or pig iron as well as fluxes in a furnace vessel, into which at least one graphite electrode projects, which is displaceable in its longitudinal direction, wherein an electric arc is ignited between the graphite electrode and the charging stock. To achieve a particularly high energy input, the graphite electrode projects into a lower part of the furnace vessel from aside and the lower part, in the region of the graphite electrode, has an enlargement radially protruding outwardly relative to the upper part.

Abstract: An electric furnace (containing an immersed electrode) and a process for the recovery of lead, arising especially from solid residues. Fines, which are a product of physically crushing spent batteries, are melted under not very reducing conditions in the presence of a small amount of carbon. This melting allows separating the crude lead and the lead-rich slag so as to remove sulphur in the form of sulphur dioxide and to optionally recover the crude lead. The lead-rich slag is then reduced with a suitable amount of carbon so as to separate the lead-free slag and the crude lead, which again can recovered.

Abstract: In order to regulate the combustion air flow rate of a flue gas collection device (1) of a metallurgical reactor (2) comprising a combustion chamber (4) supplied with air by a variable flow fan (9), a set value C.sub.0 for the oxygen content in the flue gases in the discharge duct (5) is set, the oxygen content M.sub.1 of the flue gases at the outlet of the combustion chamber (4) is measured, using C.sub.0 and M.sub.1, a setting C.sub.1 for varying the combustion air flow rate is calculated, a variable representative of the sudden variations of the flow rate of unburnt gases at the outlet of the metallurgical reactor (2) is measured and a setting C.sub.2 for the combustion air flow rate is calculated to achieve complete combustion of the unburnt gases in the flue gases; the values C.sub.1 and C.sub.2 are added to obtain a setting for the combustion air flow rate which is sent to the regulation device of the fan (9); these calculations may be carried out by electronic means (14, 15, 16).

Abstract: A furnace comprises a space overlying a charge into which space opens at least one oxygenated gas injector passing through the periphery of the furnace to deliver within this space a jet of gas that is nonradial relative to a vertical axis of the space. Each injector comprises a) a head (14) disposed within the thickness of the wall (1) of the furnace and having a gas passage having an axis (11) inclined at a predetermined angle (.alpha.) to an axis (15) that is substantially radial relative to the vertical axis of the space overlying the charge and b) a substantially cylindrical body (16) prolonging the head and the gas passage within the furnace along this substantially radial axis (15), itself substantially perpendicular to the wall (1) through which it passes. The injector is useful in an electric furnace for melting scrap for the production of steel.

Abstract: A process is disclosed, for treating dross containing a metal such as aluminum, in order to recover this metal, In this process, the dross to be treated is introduced into a rotary or oscillating furnace, in which it is heated to a temperature above the melting point of the metal to be recovered while the furnace is rotated or oscillated to cause the metal to be recovered to separate from the dross. After the separation is completed, the metal to be recovered is removed from the furnace prior to removing the balance of the dross. In this process, the furnace that is used is a radiating arc furnace having two opposite electrodes which are preferably made of graphite, between which an electrical arc is generated and maintained in order to provide the desired heating.

Abstract: A plasma ashing apparatus has a vacuum treatment chamber for receiving therein a substrate coated with a resist film, a reactive gas introduction pipe equipped with a plasma applicator, a vacuum exhaust pipe, a heating means for heating the substrate, and two pieces of electrodes disposed in parallel to each other. One of the electrodes is a substrate electrode and the other thereof is a circular counter electrode. These two electrodes are commonly connected to an RF power source to thereby constitute a cathode electrode. Multiple concentric perforations are formed in the counter electrode except for a rib portion. A central perforation is formed in the center of the counter electrode. The concentric perforations are formed at every distance, from the center, equivalent to a diameter of the central perforation, while leaving circular electrode surfaces corresponding in width to a radius of of the perforation.

Abstract: Process for melting a furnace charge, with post-combustion of the smokes by njecting an oxygenated gas in the furnace atmosphere as a series of jets flowing according to a tangential component in the space between electrodes and cylindrical furnace partition of the furnace, in a direction of injection so as to produce a rotary gas current about the vertical axis of the furnace and preferably in at least two series as two stepped levels to produce gas currents which rotate in opposite directions. Applications to electrical furnaces for the production of steel or ferro-alloys.

Abstract: In a smelting unit comprising an arc furnace and at least one shaft-like charging material preheater which is arranged laterally on the furnace vessel of the arc furnace and the interior of which is connected in a region adjoining its bottom to the interior of the furnace vessel by way of a connecting zone, and in addition burners open in the lower region of the charging material preheater, in a sump mode of operation after the tapping step, of the amount of charging material which is required for the next bath of molten material, a part thereof is charged directly into the furnace vessel in order to reduce the smelting time. That part of the charging material is preheated in a preheating chamber which is connected downstream of the charging material preheater.

Abstract: A combustion aiding apparatus for a steel-making electric-arc-furnace characterized by installing a combustion aiding burner on a balcony having an inspection-and-working opening through which to drop tapping hole filling-agent and also by making the nozzle of said combustion aiding burner freely inserted into and withdrawn from a furnace through the inspection-and-working opening, in a conventional combustion aiding apparatus for a steel-making electric-arc-furnace of eccentric bottom tapping type.

Abstract: To save energy in the production of steel in an electric arc furnace while increasing the total input of energy, the employment of carbonaceous fuels and oxygen-containing gases is proposed. The oxygen or the oxygen-containing gases are led into the furnace in the upper part of the furnace through stationary top blow-in devices (4) into the space between the pitch circle of the electrodes (10) and the furnace wall (3). The resulting intense gas flow repeatedly sucks in the reaction gases arising from the scrap or the melt being formed and burns them. The heat thus set free is transferred to the scrap and/or the melt with a thermal efficiency of at least 70%. By nozzles (2) arranged below the surface of the bath, and preferably in the furnace floor, preferably oxidizing gases are led into the melt and solid materials, particularly carbonaceous fuels, are supplied to the melt through one or more hollow electrodes (6) with an abrasion-resistant cladding.

Abstract: A system is provided for positioning a pair of electrodes on either side of the end portion of an optical fiber extending through a contact, to establish an arc through a cross-aperture in the contact and across the fiber to melt the fiber into a lens, which assures close control of the arc and which prolongs the life of the electrodes. The tips of the electrodes are positioned to lie slightly within opposite ends of the cross-aperture, to avoid establishing an arc between the electrodes which passes around the contact instead of through the cross-aperture. The electrodes are spaced apart by at least about eight times the diameter of the optic fiber, to avoid deposition of vapors from the heated optic fiber onto the electrodes. The cross-aperture extends to the tip of the contact, so the contact can be moved along its axis to a position where the electrodes lie on opposite sides of the fiber end portion.

Abstract: A system is described for forming a lens at the end of an optical fiber which extends through a hole in a contact, so the tip of the lens lies at a desired lens position located a predetermined distance rearward of the tip of the contact. The fiber is fixed to the contact at a position wherein the tip of the fiber lies forward of the desired lens position, at about the tip of the contact. The contact is positioned vertically, with the tip of the fiber pointing upwardly, and an arc is passed across the end portion of the fiber, to initially heat and bulge out a location on the fiber spaced rearward of the tip. As the fiber is heated, the tip portion falls into the bulging portion, while the bulging portion moves down, with the heating continued long enough so that the tip of the molten ball of glass lies at the desired lens position.

Abstract: A system is provided for forming an end of an optical fiber into a lens, which produces a lensed fiber having an especially smooth lens surface and high strength near the intersection of the lens and the rest of the fiber. A lens is formed by establishing a pair of electrodes on opposite sides of a fiber end portion and establishing an arc between the electrode tips for a sufficient current and time to melt the fiber end portion into a lens, with the arc being repeatedly terminated and restarted at a rate of thousands of times per second.

Abstract: A plant for the production of steel from scrap and optionally fluxes includes a shaft furnace section having a bottom to receive a liquid sump of premelt and heating means laterally entering into the lower part of its interior. A hearth type furnace section is integrally connected with the shaft furnace section, into which the premelt is transferable from the shaft furnace section.

Abstract: A method is disclosed for modifying an electric arc furnace to include oxy-fuel burners to assist in the melting of scrap metal by forming an endless melt trench in the scrap metal. Methods of melting scrap metal using an endless melt trench in such a furnace are also disclosed.

Abstract: An improvement to a scrap melting method employing an electric arc furnace, which comprises the step of heating the scrap by a powdered coal burner prior to the step of heating the scrap by the electric arc. The burning conditions are controlled so as to reduce the amount of oxidized Fe as well as the amount of NO.sub.x contained in the exhaust gases. In preferred embodiments, a pair of furnaces are employed to heat the scrap alternately by the powdered coal burner and by the electric arc.

Abstract: An electric arc furnace having at least one electrode and a burner and first and second supply systems for respectively supplying an oxygen containing gas and fuel to the burner. An exhaust gas conduit is connected to the furnace and includes a first damper for controlling the flow rate of exhaust gases and a second damper for controlling the flow of dilution air into the exhaust conduit. First and second position sensors are coupled to the first and second dampers, respectively, for sensing the positions thereof, a temperature sensor is coupled to the exhaust conduit for sensing the temperature therein and a pressure sensor is coupled to the furnace for sensing the furnace pressure. A first control is coupled to the first supply system and to the temperature sensor and to the first position sensor for initiating and controlling the flow of oxygen containing gas in relation to the temperature in the conduit and the position of the first damper.

Abstract: Rock is melted between electrodes and the resulting melt is subjected to electrolysis to recover oxygen and selected metals therefrom and to produce a melt of a unique composition so that it can be cast to produce structures with various properties.

Abstract: A vertical carbonizing furnace for use in the production of carbon fibers is provided with a vertically extending conduit of hollow rectangular parallelepiped. The lower end of the conduit is immersed in water thereby making a water seal from environmental air. The conduit is also provided with a gas withdrawal outlet which communicates with the upper portion of the conduit through a gas feeding duct for reuse. The mixture of a vapor evaporated from the water seal and an inert gas is withdrawn from the gas withdrawal outlet and fed to the upper portion of the conduit as gas for sealing thereby preventing fibers and the conduit made of carbon or graphite from being deteriorated by said vapor evaporated from the water seal and providing a gas for sealing the upper end of the conduit.

Abstract: According to the invention, there are provided improved apparatus and process for preparing high temperature reaction products in an electric furnace. Into the furnace, a combustible material and an oxygen-containing gas are fed by means of a suction-type water-cooled lance. The discharge end of the lance in the furnace is opened at a specific position within the unreacted material deposition zone in the furnace so that incomplete combustion is effected, thereby producing useful by-product gases. Cooling water is recirculated by a suction pump interposed at a position downstream of the lance outlet.

Abstract: The invention relates to a method for burning fine-grain material, particularly for the manufacture of cement clinker from cement raw meal. The material is thermally treated in a multi-stage burning process with a pre-heating stage, a calcining stage with a high-degree of calcination, a sintering stage in a very short rotary kiln and a cooling stage. Fuel is introduced both into the sintering stage in the short rotary kiln as well as into the calcinating stage. Hot exhaust air from the cooling stage is supplied both to the sintering stage as well as to the calcining stage as furnace air. The invention also relates to an apparatus for the manufacture of mineral products of the burning process such as cement clinker.