Abstract: A process and an apparatus are disclosed for improved recovery of metal from dross, wherein a dross treating furnace is provided with a refractory wall or lining with good capacity to store and conduct heat. This furnace is preheated to a desired temperature by injection of oxygen to burn non-recoverable metal remaining in the residue after tapping of the recoverable metal contained in the dross. When dross is treated in such preheated furnace, the heat emanating by conduction from the furnace wall is sufficient to melt and separate the recoverable metal contained in the dross, without addition of an external heat source, such as fuel or gas burners, plasma torches or electric arcs.

Abstract: A method is provided for treating a magnesium-containing article to form a cathodic protective coating on such article. This is done by electrochemically treating the article, acting as a cathode, in an alkaline solution, preferably at a temperature of between 40 and 80.degree. C., with a cathodic current density of 5-200 mA/cm.sup.2. The treatment produces a magnesium-containing article having a protective coating of magnesium hydride of predetermined thickness with a high count of hydrogen particles.

Abstract: The invention provides an improved near net-shape VPS formed multilayered combustion system component having an inner surface consisting of a smooth protective thermal barrier coating, and an outer layer of superalloy capable of withstanding temperatures in excess of 700.degree. C. The invention also includes the method of forming such components by first vacuum plasma spraying a suitable mold with a ceramic top coat, followed by a bond coat and followed by a thick structural layer of superalloy. The mold is then separated from the multilayered structure which results in the desired near net-shape component. Combustor liners and transition ducts of gas turbine engines can be advantageously formed in this manner.

Abstract: Erasure of an x-ray imaging device is performed by applying high voltage and erasing light simultaneously. The polarity of the high voltage may be reversed during the erasure operation. This produces an erasure that eliminates non-uniformities or ghosts arising from a previous image.

Abstract: A continuous control system for a mining or tunnelling machine having a boom (12) with a motor driven cutting head (14) at one of its ends and a rotatable turret (20) at the other end, the control system comprising angular encoders (40, 44) for continuously measuring the angles of the boom (12) and of the turret (20) and a linear encoder (55) for continuously measuring the linear position of the cutting head (14), and further having pressure transducers (P.sub.1, P.sub.2, P.sub.3, P.sub.4) for continuously measuring the pressures of the various hydraulic cylinders or drives (41, 43) used to operate the boom (12) and the turret (20). It may also have a power transducer (57) for continuously measuring the power input to the motor (18) driving the cutting head (14) to control the RPM of the latter.

Abstract: The invention provides an improved thermal barrier coating system for a hot section component. The thermal barrier coating has a metallic bond coat and a ceramic top coat made of two constituents. The top coat is formed so that there is provided a graded interface between the monolithic layers of the two top coat constituents. This allows an increase in overall thickness of the thermal barrier coating which provides a higher thermal insulation for the component being protected.

Abstract: A railing assembly is provided where the upper railing and the lower railing are interconnected with suitable cross-bars or plates and siding strips are snapped-on and locked on the sides of the railings to cover the opening and/or the ledge in the upper and lower railings and generally to strengthen and enhance the appearance of the railing assembly. Kits are also included within the scope of this invention for installing such railing assembly in conjunction with porches, stairways and the like.

Abstract: This invention discloses a method and an apparatus for gasification and vitrification of ashes, such as produced in a hog-fuel fired boiler, by means of a plasma arc. The ashes are introduced into a shaft furnace where two or three tiltable electrodes are located. The plasma arc is ignited between these electrodes which are then tilted from a horizontal to an essentially vertical position whereby the arc is lengthened and then broken into separate arcs, one between each electrode and the slag accumulated at the bottom of the furnace. This plasma arc helps to burn off the organics in the ashes, producing combustion gases that can be used as a source of energy for the boiler, and to keep the slag in molten state, which allows its periodic removal through a tap hole.

Abstract: An undercut excavation method is provided, which is particularly suitable as an undercut-and-fill mining method, wherein concrete posts are inserted into holes drilled in the ground and are used to support a concrete floor poured on their top ends, which serves as a roof for the lower excavation level. The bottom ends of these posts rest on resilient elements to provide protection against seismic events or excessive ground movements. Excavation beneath such roof is thereby safely carried out in areas prone to seismic events such as rock bursts or earth quakes or to excessive ground movements. The concrete posts may be attached to the resilient elements at their bottom ends, thereby producing yielding posts suitable for such excavation. For still greater safety, a double post system may be used, which involves placing a second post beside the first after excavation on a given level and tying them all together with the concrete used to make the floor/roof for the next lower level of excavation.

Abstract: A stress measuring rock support device is provided, such as a cable bolt or friction stabilizer, which has an internal longitudinal cavity, such as a groove or a flat section on the kingwire or a hollow core in the kingwire or the like. One or more rigid wires or filaments extend in such cavity and their ends are anchored at predetermined anchor points within the cavity. The other ends of the rigid wires or filaments are spring-loaded and are provided with movable actuators having electrical contacts which are in contact with a linear potentiometer and measure the displacement of the actuators resulting from the stretch of the cable. This is then correlated to measure the cable load or strain resulting from the stress applied to the rock support device. The spring-loaded arrangement as well as the linear potentiometer and the actuators with electrical contacts are enclosed within a suitable cover to form an instrumentation head assembly for the rock support device.

Abstract: A multilayer plate for X-ray imaging is provided, which includes a substrate, a biasing electrode and a selenium-based membrane sandwiched between the substrate and the biasing electrode. The selenium-based membrane comprises a thick photoconductive layer of doped amorphous selenium and one or two thin buffer layers. One of the buffer layers is an amorphous arsenic triselenide layer positioned between the photoconductive layer and the substrate, and the other buffer layer is a unipolar conducting layer of alkali doped selenium positioned between the photoconductive layer and the biasing electrode. Preferably both layers are included. A method of producing such multilayer plates is also disclosed.

Abstract: A multi-stage froth flotation process is provided for concentrating sulphide minerals or middlings containing non-ferrous metal values such as nickel, cobalt and copper, which co-exist with significant amounts of pyrrhotite. The process is carried out without relying on any specific reagent as pyrrhotite depressant, but rather by exploiting the natural pulp environment with low REDOX potentials generated by mild steel grinding media in the grinding step preceding the froth flotation. The concentrate from the flotation stage(s) in which the REDOX potential rises above a predetermined value, is recycled back to the grinding step and/or to preceding flotation stage(s) from which concentrate is collected as the final product or is subjected to an up-grading in a further cleaning stage.

Abstract: The invention overcomes the problem of paper edge overdrying during the paper drying process on paper machine drying cylinders. It comprises applying a thin ceramic coating onto the circumferential exterior surface of the cylinder near the cylinder edges, thereby forming a thermal barrier coating which decreases paper drying rate at said edges and reduces or eliminates paper edge overdrying.

Abstract: A method of pressure leaching nickel and cobalt from sulphidic precipitates is provided, wherein such precipitates are leached with chlorine at a controlled redox potential of between 400 and 550 mV (Ag/AgCl), catalysed by copper, and at a temperature of between 120.degree. and 160.degree. C., to dissolve at least 80% of cobalt and to oxidize less than 10% of sulphur to sulphate.