Abstract: An adjustable mold for direct chill casting of metals has longitudinally movable end walls which are clamped between the mold side walls during casting. Each end wall is secured to a sliding carriage which supports the end wall and allows it to be moved along the end portions of the side walls. The sliding suspender has a clamping mechanism which applies a clamping force to one or both of the side walls, the force being transversely directed through a center of the end wall. The side walls are pivotable relative to one another to allow clamping and unclamping of the end walls. Preferably, one end of each side wall is pivotable so as to transversely displace the opposite end of the side wall, with the pivoting ends of the respective side walls preferably being opposite one another across the mold.

Abstract: A furnace binding and adjustment system for maintaining a refractory furnace hearth under compression utilizes a plurality of buckstays connected at their upper and lower ends by tie members. A fluid-pressurized tensioning device, preferably a hydraulics device, is provided at the ends of at least some of the tie members to permit some relative movement between the tie member end and the buckstay to permit adjustment of compressive forces applied to the refractory hearth. The use of multiple hydraulic devices permits simultaneous activation of the tensioning devices, and also permits the hydraulic pressure in the cylinders to be accurately adjusted and monitored from a remote location.

Abstract: A process for purification of molten salt electrolytes containing magnesium chloride in which oxygen-containing impurities such as magnesium hydroxychloride are destroyed both electrolytically and chemically. The process comprises passing a direct current through a magnesium chloride-containing molten salt electrolyte, thereby electrolyzing a portion of the oxygen-containing impurities at the anode. In addition, the voltage and current of the direct current are sufficiently high to cause electrolysis of a small proportion of the magnesium chloride present in the electrolyte to thereby produce finely dispersed droplets of elemental magnesium in the electrolyte. The droplets of elemental magnesium react chemically with oxygen-containing impurities present in the electrolyte. The purified electrolyte is transferred to an electrolytic cell for the production of magnesium metal and chlorine gas.

Abstract: A power control system for an AC electric arc furnace. The control system includes variable reactors located intermediate a furnace power supply and arc electrodes that are height adjustable. The control system monitors operating characteristics of the furnace that are indicative of the active power consumption of the furnace and adjusts the variable reactors and the electrode height so as to minimize variations in the active power consumption. Loss of electrode arc can be predicted and countered by lowering the electrodes and decreasing the reactance of the variable reactors.

Abstract: A method for raising awareness of sustainable development issues involves the identification of a number of indicators which are representative of the sustainability issues relating to an activity, for example an industrial or infrastructural development activity. Data relevant to each of the indicators is collected and analyzed, and a value is then assigned to each indicator which is based on the collected data. The indicator values are then converted to indicator scores which may be either qualitative or quantitative, in order to determine to overall impact of the activity on sustainability. The analysis can be repeated over time to determine the overall impact of the activity on sustainability, and the results can be aggregated to monitor an organization's progress toward sustainability.

Abstract: Variable shunt and series connected reactors are used in a complimentary combination in an electric arc furnace to provide improved flicker control. A power control system for an time-varying AC load, such as an electric arc furnace, connected to an AC power supply line includes a first variable reactance intermediate the power supply line and the load, and a second variable reactance connected in parallel with the power supply line. A control system is provided for (i) monitoring load current and adjusting the first variable reactance in response to changes in the monitored load current; and (ii) monitoring reactive power draw by the load and adjusting the second variable reactance in response to changes in the monitored reactive power draw. The first variable reactance and second variable reactance are each primarily used to mitigate flicker at different times during the load operation.

Abstract: A casting furnace for continuous casting of magnesium comprises a furnace body divided into at least two compartments by at least one vertical weir. Inside each compartment, an upper layer of molten magnesium is in contact with a lower layer of a liquid heating medium, preferably a molten salt. The top of the weir is situated below a maximum level of the molten magnesium in the furnace. The weir is free of openings between its top and the magnesium/salt interface. The molten magnesium from primary (electrolytic) production or an alloy preparation furnace is introduced into a feed compartment of the furnace through a discharge pipe having means to direct the magnesium horizontally along the magnesium/salt interface, thereby minimizing intermixing of the magnesium and salt layer.

Abstract: A power control system for an AC electric arc furnace. The control system includes variable reactors located intermediate a furnace power supply and arc electrodes that are height adjustable. The control system monitors operating characteristics of the furnace that are indicative of the active power consumption of the furnace and adjusts the variable reactors and the electrode height so as to minimize variations in the active power consumption. Loss of electrode arc can be predicted and countered by lowering the electrodes and decreasing the reactance of the variable reactors.

Abstract: A process for purification of molten salt electrolytes containing magnesium chloride in which oxygen-containing impurities such as magnesium hydroxychloride are destroyed both electrolytically and chemically. The process comprises passing a direct current through a magnesium chloride-containing molten salt electrolyte, thereby electrolyzing a portion of the oxygen-containing impurities at the anode. In addition, the voltage and current of the direct current are sufficiently high to cause electrolysis of a small proportion of the magnesium chloride present in the electrolyte to thereby produce finely dispersed droplets of elemental magnesium in the electrolyte. The droplets of elemental magnesium react chemically with oxygen-containing impurities present in the electrolyte. The purified electrolyte is transferred to an electrolytic cell for the production of magnesium metal and chlorine gas.

Abstract: An electrode seal for an electric arc furnace comprises an annular support ring having an internal diameter substantially greater than the diameter of the electrode, and which is secured to the furnace roof by a plurality of mounting feet. The annular support ring has an upper annular sealing surface on which is supported an annular sealing ring having an internal diameter which is approximately the same as the diameter of the electrode to form a substantial seal therewith. The sealing ring has a lower annular sealing surface which engages the upper sealing surface of the support ring, while allowing limited sliding movement of the sealing ring along its lower annular sealing surface.

Abstract: A method for effecting direct reduction of iron oxides in the form of lumps or pellets, in which an ore burden is passed downwardly successively through prereduction and metallization zones of a shaft furnace while passing a flow of rich fuel gas produced by external partial combustion upwardly in counter current through the prereduction zone, and passing a flow of reducing gas in cocurrent though the metallization zone. The flow of reducing gas is an independent flow that has not been subject to external combustion, and an intermediate zone is provided forming a narrowed throat between the prereduction and metallization zones. The reducing gas is introduced at a boundary between the intermediate and metallization zones, such that passage of rich fuel gas from the prereduction zone to the metallization zone is inhibited. The gas flows should be controlled so that about 5% to 10% of the volume of reducing gas passes upwardly from the intermediate zone to the prereduction zone.

Abstract: A sports/recreation facility is provided with seating bank around a playing area (2), and a grass playing surface (12) which is withdrawable from the playing area. The playing area is defined within one end of a shallow dock (16), the dock extending over the playing area and also extending sufficiently outside the playing area in one direction to define an area outside the playing area and seating banks having dimensions at least equal to the playing area. A shallow barge (14) is floatable within the dock and supports the playing surface for movement within the dock between the playing area and the outside area. The water (18) for introduction into the dock is stored within the barge.

Abstract: An improved return path for electric current through a conductive hearth of a direct current arc furnace is provided by pressing a ring of water cooled copper blocks into the periphery of a sidewall of the hearth of the furnace, the hearth having zones of conductive refractory providing an electrical path between the contents of the furnace of the copper blocks. The hearth is compressed by a tensioned peripheral band which may also support the blocks. The peripheral water cooled copper blocks may be divided into multiple groups, each group connected to one pole of a direct current power supply, the opposite pole of which is connected to a suspended electrode, permitting control of arc deflection.

Abstract: In order to abate unwanted noise having as its source a stack or duct of large cross-sectional dimension, a venturi is installed in the duct such as to suppress at least the highest order modes of sound propagation in the stack or duct. The invention is most useful with stacks or ducts having a cross-sectional dimension exceeding 50 cm.

Abstract: A multipurpose arena has a platform providing a performing, playing or exhibition area which can be raised or lowered to allow for different configurations of banked seating. The raising and lowering is achieved by displacement of air in or out of an air vessel formed beneath the platform, either by a hull floating in a well which can be emptied of water by air pressure or scuttled, or by a skirt depending from the platform and sealed to underlying structure. If a skirt is used, space can be reclaimed within a structure inside the skirt which provides a reaction surface for the air pressure. The skirt may be sealed to the underlying structure by a water seal in a trough, or by sealing the lower edge of a telescoping skirt to the structure.

Abstract: An electrode seal for arc furnaces, particularly arc furnaces for steel making, has a first element in the form of a water cooled copper sleeve lining an aperture in the furnace roof for passage of an electrode, the sleeve having an upper surface engaged by a lower surface of a horizontally slidable seal ring formed by beryllium copper water cooled segments which abut end-to-end to form a close fitting collar around the electrode having an internal diameter the same as the external diameter of the electrode. The segments are spring loaded radially against each other and so as to center them over the aperture, so as to accommodate any minor oversize or irregularities of the electrode, as well as damping horizontal movement of the latter, and are also spring-urged downwardly against the sleeve. Water passages in the segments and in the sleeve are connected in series, and water piping and spring loading apparatus are arranged to leave part of the periphery of the seal free, allowing close grouping of electrodes.

Abstract: In a process for the hydrometallurgical treatment of electric arc furnace dusts which includes an acetic acid leach, the acetic acid solution used to perform the leach is made strong enough to dissolve heavy metal residues in the dusts, the iron-containing residues of which are recycled to a steel producing furnace. Zinc and other heavy metals are precipitated from hot acetic acid solution as useful products by the use of hydrogen sulphide. Calcium is then precipitated from the acetic acid solution as a clean gypsum using a deficiency of sulphuric acid, thus avoiding leaving sulphate ions in solution in sufficient concentration to interact with the dust and form sulphates in the iron containing residues when the acetic acid is recycled to the leaching step.

Abstract: A portable device is provided for turning billets supported on stands for inspection. The device has a frame, a crank arm mounted in the frame for movement through a quadrant by a hydraulic cylinder, a billet engaging bracket on the end of the crank, and further billet engaging frames extending from the frame to either side of the crank so as to sustain on adjacent billets the reaction from the crank arms as its bracket turns a billet. The turning action is improved by inclusion of a lost motion link between the crank arm and the cylinder. To make the device easier and lighter to handle, it is spring suspended from a movable stand which also supports a power pack for operating the cylinder.

Abstract: A continuous centrifugal casting machine employs a rotating water cooled mould in which a tubular mould cavity is formed by a number of pallet conveyors, each having an upper run defining a part cylinder. The conveyors are driven so that the tubular mould which they form moves with the casting, thus eliminating relative movement between the mould and the casting. The conveyors are housed inside a rotating drum so that centrifugal force causes molten metal such as steel poured against the wall of the mould cavity at one end to form a comparatively thin walled tube which is withdrawn from the other end of the mould cavity. The tube may be spirally slit to form sheet.

Abstract: In a bridge crane, a rigid rectangular crane bridge frame is supported on a main runway by a truck at each corner, and in order to eliminate loadings on the trucks due to distortion of the runway, the trucks on one side of the bridge support the bridge frame through interlinked levers forming part of an equalizing linkage.