Abstract: A process for cooling an acid that is withdrawn from an absorption apparatus of a sulfuric acid plant includes pumping the acid to be cooled from an acid pump tank and supplying the acid to a shell space of a heat exchanger. Water is supplied as a heat transport medium to heat transfer elements disposed in the shell space so as to at least partially convert, by heat transfer from the acid, the water to steam. The acid which was cooled in the heat exchanger is supplied back to the absorption apparatus. The water is separated from the steam in a steam drum. The separated water is recirculated to the heat exchanger using a pump.

Abstract: A method for producing a clinker substitute for use in cement production includes predrying clay with an iron content >1.5 wt-% in a form of iron oxides and a kaolinite content <40 wt-% to a moisture <10 wt-%. The clay is comminuted to a grain size <2 mm. The clay is calcined by thermal treatment in a furnace at a temperature of 600 to 1000° C. The clay is thermally treated under reducing conditions at a temperature of 600 to 1000° C. so as to form a reduction product. The reduction product is intermediately cooled to a temperature <300° C. and finally cooled.

Abstract: A concentrate burner of a suspension smelting or suspension converting furnace includes a reaction gas feed, a powdery solid matter feed and a concentrate distributor. An arrangement for feeding powdery solid matter to the concentrate burner includes a first powdery solid matter discharge pipe for feeding powdery solid matter into the powdery solid matter feed of the concentrate burner. The first powdery solid matter discharge pipe is provided with a first partition, which divides solid matter, for dividing the first powdery solid matter discharge pipe into two essentially similar discharge pipe parts. The powdery solid matter feed of the concentrate burner comprise an annular concentrate discharge channel that surrounds the concentrate distributor of the concentrate burner. Each discharge pipe part of the first powdery solid matter discharge pipe is at least partly divided into two discharge pipe portions by a second partition.

Abstract: A TSL lance has an outer shell of three substantially concentric lance pipes, at least one further lance pipe concentrically within the shell, and an annular end wall at an outlet end of the lance which joins ends of outermost and innermost lance pipes of the shell at an outlet end of the lance and is spaced from an outlet end of the intermediate lance pipe of the shell. Coolant fluid is able to be circulated through the shell, by flow to and away from the outlet end. The spacing between the end wall and the outlet end of the intermediate pipe provides a constriction to the flow of coolant fluid to increase coolant fluid flow velocity therebetween. The further lance pipe defines a central bore and is spaced from the innermost lance pipe of the shell to define an annular passage, whereby materials passing along the bore and the passage mix adjacent to the outlet end of the lance. The end wall and an adjacent minor part of the length of the shell comprise a replaceable lance tip assembly.

Abstract: A process for lowering the carbon content in ash includes introducing the ash having a carbon content of 1 to 20 wt-% into a reactor where the ash is burnt at a temperature between 700 and 1100° C. Fuel is also introduced into the reactor. During combustion, microwave radiation is fed into the reactor. At least part of the energy released during the combustion is recovered.

Abstract: The invention relates to a method and arrangement for separating two solutions mixed in dispersion into two solution phases in a liquid-liquid extraction separation cell. The arrangement includes a first guide wall extending along the whole width of the cell with respect to the vertical direction at an inclined angle. The first guide wall includes a bottom edge, which is located at a distance from the cell bottom, so that a clearance gap is formed between the bottom edge and the cell bottom. The arrangement also includes a second guide wall essentially parallel with the first guide wall and placed at a distance therefrom. Between the first guide wall and the second guide wall an uptake shaft is formed extending diagonally upwards at the inclined angle. The second guide wall is pressed tightly against the cell bottom, and includes a number of vertical slots.

Abstract: A lance (10), for conducting a pyrometallurgical operation by top submerged lancing (TSL) injection, wherein the lance (10) has at least an inner pipe (12) and outer pipe (14) which are substantially concentric. The lower outlet of the inner pipe (12) is set at a level relative to the lower, outlet end of the outer pipe (14) required for pyrometallurgical operation. The lance (10) further includes a shroud (22) through which the outer pipe (14) extends and which is mounted on and extends along an upper portion of the outer pipe (14) to define with the outer pipe (14) a passageway (28) along which gas is able to be supplied for flow towards the outlet end of the outer pipe (14) for discharge exteriorly of the lance (10). The shroud (22) is longitudinally adjustable relative to the outer pipe (14) to enable substantial maintenance of or variation in, a longitudinal spacing between the outlet ends of the shroud (22) and the outer pipe (14).

Abstract: A process for at least one of a chemical and a physical treatment of fluidizable substances in a reactor. The process includes introducing a hot gas into an interior of the reactor through a gas supply tube and cooling at least one of the hot gas and the gas supply tube with a coolant. The cooling is performed by contacting the hot gas with the coolant so as to provide a temperature of a wall of the gas supply tube at least 50° C. lower than a temperature of the gas at an inlet of the gas supply tube facing away from the interior of the reactor.

Abstract: A sealing device is arranged around a rod electrode extending vertically through an aperture made in the ceiling of an arc furnace and being vertically movable inside the furnace to prevent the access of gases from the furnace through the aperture to the atmosphere, and on the other hand to prevent air from flowing from the atmosphere into the furnace. The sealing device comprises a gas distribution chamber provided with an inlet channel for feeding essentially passive gas, such as nitrogen or air, into the gas distribution chamber. The sealing device also includes a slit nozzle encasing the electrode, through which nozzle a gas jet is arranged to be discharged from the gas distribution chamber towards the electrode in a direction that is at an angle with respect to the horizontal plane and has a slightly upwards inclined orientation, and that is, with respect to the furnace interior, pointed outwardly, so that the sealing is carried out owing to the effect of the created stagnation pressure.

Abstract: An apparatus for the treatment of at least one of solids and gases includes a fluidized-bed reactor configured to fluidize the solids using fluidizing gas and to at least one of thermally and chemically treat the solids. A centrifugal separator is configured to separate the fluidizing gas and the solids from each other. A transfer duct connects the fluidized-bed reactor and centrifugal separator to each other. The transfer duct has a trapezoidal cross-section in a vertical direction and in a horizontal direction. The transfer duct branches off from the fluidized bed reactor with a cross-section having a horizontal dimension that is greater than a vertical dimension. The cross-section of the transfer duct expands downwards in the vertical direction from the fluidized-bed reactor to the centrifugal separator. The cross-section of the transfer duct tapers in the horizontal direction from the fluidized-bed reactor towards the centrifugal separator.

Abstract: The invention relates to a method for controlling suspension (8) in a suspension smelting furnace (1), to a suspension smelting furnace, and to a concentrate burner (2). The method comprises feeding additionally to pulverous solid matter (6) and additionally to reaction gas (7) reducing agent (13) into the suspension smelting furnace (1), wherein reducing agent (13) is fed in the form of a concentrated stream of reducing agent (13) through the suspension (8) in the reaction shaft (2) onto the surface (9) of the melt (10) to form a reducing zone (15) containing reducing agent (13) within the collection zone (14) of the melt (10).

Abstract: A packed tower for the absorption of water or SO3 in sulfuric acid includes a jacket and a domed grid disposed within the jacket. The domed grid is held on an L-shaped ring such that a gap is formed between an outside diameter of the domed grid and the jacket. A bed of packings is held on the domed grid through which the sulfuric acid charged from above trickles. A gas supply tube is disposed in a lower region of the tower. A gas outlet is disposed above the bed. An acid outlet is disposed in the lower region of the tower.

Abstract: The subject of the invention is a method for fabricating the discharge end (2) chute arrangement (3) of a liquid-liquid extraction settling tank and the corresponding chute arrangement. The chute arrangement (3) comprises at least one chute member (4, 5; 6), which is made of fiber-reinforced plastic composite. The chute member (4, 5; 6) is manufactured by the filament winding technique essentially making a tubular hollow piece.

Abstract: The invention concerns a system of gas ducts (6) for transporting gas, for example, into electrolytic equipment, in connection with which there are means (13) for taking at least gas into the system of gas ducts, whereby there is a suitable number of gas supply holes (7) in the system of gas ducts in a wall (19) limiting the system of gas ducts, whereby the material, such as gas, flowing in the system of gas ducts (6) is prevented at least in part from passing through the wall (19) of the system of gas ducts (6). The invention also concerns equipment and a method for electrolytic recovery of metal, such as copper.

Abstract: The invention provides several improvements in feedwells, one of which being a feedwell comprising a mixing zone for dissipating the kinetic energy of a fluid comprising pulp, a settling zone for promoting flocculation of the pulp and at least one inclined deflecting element for at least partially separating the mixing zone from the settling zone. Other improvements include a shelf at least partially defining an inclined path for removing material from the shelf into a feedwell chamber; at least two outlets arranged in a substantially concentric relationship with respect to each other; a portion of a second conduit varies in its cross-sectional size and/or shape so as to connect a feed inlet to a first conduit; and a partition for partially separating an outer mixing zone and an inner settling zone.

Abstract: The invention relates to a method for removing arsenic as scorodite from solutions that contain iron and arsenic. In accordance with the method, arsenic is first precipitated as ferric arsenate and subsequently processed hydrothermally into crystalline scorodite.

Abstract: A heat exchanger for use in a contact group of a sulfuric acid plant includes a chamber in which a tube bundle is arranged on a circular ring. A gas space is formed between the tube bundle and a chamber casing surrounding the tube bundle. A gas supply opening is provided in the chamber casing and is configured to introduce a gas into the gas space substantially radially to the tube bundle. A gas outlet opening adjoins an interior space enclosed by the tube bundle in a substantially axial direction. A center of the tube bundle is offset with respect to a center of the chamber casing in a direction opposite to the gas supply opening.

Abstract: A process for refining oil-containing includes introducing the oil-containing solids to a reactor so as to expel an oil-containing vapor from the solids at a temperature of 300 to 1000° C. The oil-containing vapor expelled from the reactor is supplied to a cracker so as to crack heavy oil components of the oil-containing vapor. The cracked heavy oil components obtained in the cracker are separated and withdrawn from the cracker. The solids left in the reactor and an unevaporated fraction of heavy hydrocarbons are introduced into a furnace. The unevaporated fraction of heavy hydrocarbons in the furnace are burned at a temperature of 600 to 1500° C. The solids from the furnace are recirculated into the reactor. A conveying gas is supplied into a rising pipe, wherein the stream of solids withdrawn from the furnace is fluidized by the conveying gas and transported to the reactor through the rising pipe.

Abstract: An apparatus for the thermal treatment of lump or agglomerated material in a firing machine includes a travelling grate configured to convey the material through the firing machine. A firing chamber has a ceiling and side walls and is configured to generate temperatures required for the thermal treatment. The ceiling has a plurality of openings and the side walls have a plurality of burners that are directed obliquely upwards. A cooling zone is configured to pass cooling gases through the thermally treated material so as to heat the cooling gases. A recuperation tube is configured to recirculate the heated cooling gases to the firing chamber through the openings in the ceiling.

Abstract: A lance for conducting a pyrometallurgical operation by top submerged lancing (TSL) injection, has inner and outer substantially concentric pipes. The lower end of the inner or at least a next innermost pipe is set at a level relative to the lower end of the outer pipe required for the pyrometallurgical operation. The relative positions of the inner and outer pipes are longitudinally adjustable to enable the length of the mixing chamber to be maintained at a desired setting during a period of use to compensate for the lower end of the outer pipe wearing and burning back.