Abstract: A cathode plate and method for electro-refining or electro-winning of metal. The cathode includes a cathode blade and hanger bar. A quantity of electrically conductive material is wrapped around the hanger bar and along the cathode blade to a position, in use, proximate the level of electrolyte in the electrolytic bath. The provision of a deeper and preferably thicker coating of electrically conductive material, as compared with conventional cathode plates, reduces power consumption in the electrolytic circuit.

Abstract: A cathode plate and method for electro-refining or electro-winning of metal. The cathode includes a cathode blade and hanger bar. A quantity of electrically conductive material is wrapped around the hanger bar and along the cathode blade to a position, in use, proximate the level of electrolyte in the electrolytic bath. The provision of a deeper and preferably thicker coating of electrically conductive material, as compared with conventional cathode plates, reduces power consumption in the electrolytic circuit.

Abstract: A hangar bar for a cathode plate and a method of producing a cathode for electrolytic recovery of metal. The hanger bar comprises a support element which is preferably stainless steel and hollow. An electrically conductive metal cladding is affixed the stainless steel bar by any appropriate mechanism, eg interference fit, welding, chemical or mechanical fastening or coextrusion or roll forming. Affixing the cladding to the stainless steel support element has significant advantages over conventional electroplating techniques including that a more precise engineering specification can be applied to the cladding thickness. This is important to maintain vertical alignment of the cathode plate in the electrolytic cell.

Abstract: A hangar bar for a cathode plate and a method of producing a cathode for electrolytic recovery of metal. The hanger bar comprises a support element which is preferably stainless steel and hollow. An electrically conductive metal cladding is affixed the stainless steel bar by any appropriate mechanism, eg interference fit, welding, chemical or mechanical fastening or coextrusion or roll forming. Affixing the cladding to the stainless steel support element has significant advantages over conventional electroplating techniques including that a more precise engineering specification can be applied to the cladding thickness. This is important to maintain vertical alignment of the cathode plate in the electrolytic cell.

Abstract: An attrition mill comprising a grinding chamber (1), an axial impeller (10), a chamber inlet (3) for admitting coarse particles and a separator comprising a chamber outlet (6) through which fine particles exit from the chamber. The mill is characterized in that a classification as between coarse and the fine particles is performed in the mill upstream of the separator.

Abstract: An attrition mill comprising a grinding chamber (1), an axial impeller (10), a chamber inlet (3) for admitting coarse particles and a separator comprising a chamber outlet (6) through which fine particles exit from the chamber. The mill is characterized in that a classification as between coarse and fine particles is performed in the mill upstream of the separator.

Abstract: An elongate lance (4) is raised or lowered by means of a carnage (7) which is guided by vertical channels (8). The lance has lateral projections (18) whereby it is supported in a cradle (17) mounted to carriage (7) via springs (29). The apparatus permits the lance lower end (12) to be submerged in bath (3) and permits restricted lateral movement of the lance lower end.

Abstract: Metal vapor, for example zinc fume in the offgas of a smelting furnace, is captured by bringing the stream into direct contact with a fluidized bed of solid particles having a particulate loading of greater than 10 kg/m.sup.3 and preferably greater than 400 kg/m.sup.3. The thermal mass and temperature of the bed is such as to rapidly quench the vapor in the case of zinc from above 960.degree. C. to below 419.degree. C. in less than 100 milliseconds, whereby the vapor condenses in the bed and is recovered as zinc metal in acceptable yield.

Abstract: The invention relates to a method of ore beneficiation.The process comprises:(1) grinding the ore to produce a first product comprising ground ore and ground gangue,(2) separating the first product into a fraction having particles of a selected size range and a remainder,(3) separating at least a part of the remainder into a ground ore fraction and a ground gangue fraction,(4) combining the particles of selected size range from step (2) with the ground ore fraction of step (3), and(5) autogenously and/or semi-autogenously grinding the combination of step (4).The process is particularly suitable for lead and/or zinc sulphide ores.In step (5) at least 80% of the resulting ore can be ground to a particle size of less than 6 microns.

Abstract: A method for the treatment of a mixture of lead dusts and pyritic concentrates said method including the steps of:a) feeding a mixture of lead dust and pyritic concentrate to a furnace containing molten slag;b) smelting the mixture by injecting air or oxygen enriched air into the slag by means of a submerged lance to produce a lead bearing slag; andc) recycling fume to the furnace.A method for the treatment of lead dusts, without pyritic concentrate, said method including the steps of:a) feeding lead dust to a furnace containing molten slag;b) smelting the dust by injecting air or oxygen enriched air into the slag by means of a submerged lance to produce a lead bearing slag; andc) recycling fume to the furnace.

Abstract: Disclosed is a method for recovering lead from a scrap which contains lead oxide, lead sulfate and antimony in an oxidized state. The method comprises the steps of:(a) continuously charging a refractory lined reaction vessel with the scrap together with a reductant effective for reducing lead oxide;(b) melting and agitating the charged material by means of a submerged lance at a temperature of from about 900.degree. C. to about 1150.degree. C. whereby some lead oxide of the scrap is reduced to form molten lead;(c) forming a slag layer above the molten lead produced in step (b);(d) maintaining an amount of lead oxide in the slag layer;(e) removing the molten lead, the removed lead having less than 0.5% by weight of antimony; and(f) concentrating as oxide in the slag layer the antimony oxide in the scrap.

Abstract: An apparatus and method for removing noise common to correlated real process derived signals. The method comprise the steps of determining the positive time cross correlation function, the negative time cross correlation function, and determining the difference between those functions. Apparatus for performing the method includes single bit correlator which evaluates the signals even when the input signals are resolved to more than one bit resolution. A signal processing system is employed to update smoothed estimates of the difference between functions at a rate equal to the sampling rate and to evaluate the median of the most likely time delay.

Abstract: An inflatable borehole plug is disclosed, the inflation of which is achieved by chemical reaction of two co-reagents disposed therein which results in evolution of a gas. The borehole plug can be dropped or lowered down a borehole to a preselected position since the extent of gas-producing chemical reaction is able to be delayed following initiation of mixing of co-reagents, by delay means in the borehole plug, for sufficient time to enable placement of the borehole plug.

Abstract: Lead constituents may be removed from a dross to produce a copper matte low in lead assay by melting the dross at temperature in excess of 900.degree. C., allowing the molten dross to separate into a lead bullion layer and a matte layer, removing the lead bullion layer from the matte layer, then heating the matte layer to a temperature in excess of 1000.degree. C., and removing the lead sulphide therefrom as a fume.

Abstract: Flaws may be detected in conveyor belting in motion by transmitting ultrasound to the belting at one zone, detecting ultrasound propagated by the belting from the one zone to another zone spaced apart from the first and issuing a signal responsive to any ultrasound detected, whereby a signal is obtained which is indicative of discontinuities in the belting intermediate the zones. Preferably, a column of water extending between an ultrasonic transducer and the belt is used for ultrasonic coupling during motion of the belt, and tracking means are provided to maintain the column at constant length. With proper frequency selection, ultrasound can be transmitted a surprising distance through conveyor belting made of rubber-like material.

Abstract: The invention comprises a filtration unit which retains particles from air passed through a filter medium, a transport mechanism which moves the medium to a station where the particles are subjected to X-rays, apparatus responsive to X-ray fluorescence exited by the X-rays in a predetermined element, for example lead, during a predetermined time interval and issuing a count signal indicative of quantity of the element and a microprocessor for controlling the transport and counting apparatus.

Abstract: Lead is obtained from lead sulfide ores or concentrates without prior sintering or roasting by the steps of adding the lead sulfide to a molten slag, injecting sufficient oxide to below the surface of the molten slag and vigorously agitating the slag whereby substantially to oxidize the lead sulfides to lead oxides, and then reducing the lead oxides. The slag is preferably agitated by means of a lance. The reduction stage may follow the oxidation stage in the same vessel or may be conducted in another vessel.

Abstract: Apparatus for measuring the bulk density and mass flow rate of pulverized coal entrained in air along a duct 6 comprises beta radiation source means 7, radiation detection means 8 and a shield 9 to intercept direct radiation falling on the detector means which thereby measures the diffuse radiation scattered by the coal particles. That measurement plus a signal indicating linear coal particle speed is fed to a data processor which calculates the bulk density and mass flow rate.

Abstract: This invention relates to a device for providing data for determining a non-horizontal change from one direction to another of a reference axis fixedly associated with a body.The apparatus uses gravity sensor devices, such as accelerometers, to provide data for determining change in both azimuth and slant angle. In some embodiments that data may be derived from the signal of a single accelerometer.Some embodiments of the invention are probes for surveying in geological boreholes. In some of such embodiments a single gravity sensor is fixed to a mass which is mounted for free rotation.Drive elements are provided whereby the mass may be rotated and then allowed to rotate undriven.Thus the direction in which the sensor is responsive to the gravity vector is, due to inertia of the mass, independent from random axial rotation of the probe.