Noranda Inc.

Noranda Mines Limited

Frank Kitzinger

Vladimir M Labuc

Gregory A Wint

John G Peacey

Michel Hamelin

John M Lucas

Frank R Rosenblum

George Houlachi

Albert Pelletier

M Barakat Janjua

David Sprott

Michel Menard

Jacques Nantel

Jean-Claude Viens

Ralph R Ebersole

A magnetic testing device for obtaining a damaged index of an elongated magnetically-permeable object in real time includes a permanent magnet assembly with spaced-apart poles, a tubular pole piece adapted to surround the object, Hall effect devices placed in the magnetic flux path, a leakage flux sensor installed between the pole pieces, and a real time signal processing unit. The signal processing unit provides local fault (LF) signals generated by the leakage flux sensor, and loss of metallic area (LMA) signals generated by the Hall effect devices. The standard deviations of the LF signals are summed, the root-mean-square of the LF signals is summed, the absolute values of the LF signals are integrated, and the LMA signal is multiplied by a coefficient which is dependent on the object construction. The damage index is then determined using the thus-calculated values. Preferably, when a wire rope is passed through the monitoring device, the damage index is given to the user in a hand-held display means. Preferably, no interpretation is required by the user.

Wire rope damage index monitoring device

A magnetic testing device for detecting loss of metallic area and internal and external defects in elongated magnetically-permeable objects includes a permanent magnet assembly having poles adapted to be spaced apart in the longitudinal direction of an elongated object for inducing a longitudinal magnetic flux in a section of the object between the poles of the magnet assembly, the magnet assembly being strong enough to magnetically saturate the section of the object. A tubular pole piece is arranged to surround the object adjacent each pole of the permanent magnetic assembly for directing the magnetic flux into the object at one pole and out of the object at the other pole. Hall effect devices are placed in the path of the magnetic flux for sensing the reduction of the flux passing through the elongated object due to any reduction of cross-sectional area of the elongated object between the pole pieces caused by loss of metallic area in the elongated object. A leakage flux sensor is installed between the pole pieces for detecting an external and internal defects in the objects. Circuitry is provided for increasing the linear resolution of the metallic area measurement of the object, whereby signals obtained correspond more closely to the variations in the metallic area of the elongated object. Preferably, the circuitry combines the local fault (LF) signal with the loss of metallic area (LMA) signal to benefit from both the high linear resolution of the LF signal and the long range stability of the LMA signal to improve the resolution of the LMA signal.

Apparatus for increasing linear resolution of electromagnetic wire rope

A method and an apparatus for on-line monitoring the quality of a purified metal sulphate solution is disclosed. The method comprises the steps of depositing metal from the purified metal sulphate solution onto a working electrode submerged in the solution by passing constant current through the solution at a current density in the range of 25 to 150 mA/cm.sup.2 for a predetermined time interval, dissolving the metal deposited on the working electrode by reversing the polarity of the potential applied between the working electrode and a counter electrode so as to pass a reverse current of the same current density through the solution until all zinc is removed from the working electrode as sensed by a sudden change in electrode potential, deriving the quality index of the solution by calculating the ratio of the dissolution time over the deposition time, and restoring the surface of the counter electrode by effecting the dissolution of the metal deposited on the counter electrode at the end of each measurement.

Method and apparatus for on-line monitoring the quality of a purified

A blasting method which comprises delivering electrical energy at a rate of at least 100 megawatts per microsecond until a peak power of at least 3 gigawatts is reached across the gap of two poles of a coaxial electrode assembly immersed in an electrolyte within a confined area of a substance to be blasted. A dielectric break-down of the electrolyte in the confined area is produced resulting in the formation of plasma within the confined area which creates a pressure sufficient to blast the substance in the manner of a high explosive charge.

Plasma blasting method

A spark gap switch is disclosed. The spark gap switch comprises an anode and a cathode having facing surfaces separated by a predetermined gap, a trigger electrode located in the vicinity of such gap, and a piezoelectric generator connected between the trigger electrode and the cathode for triggering the spark gap switch.

Electromechanically triggered spark gap switch

An accelerometer for blast monitoring comprises at least one piezoelectric transducer having a piezoelectric membrane attached along the edge thereof to the sidewall of a suitable container and mounted for free movement in such container for generating a high impedance electrical output signal upon deformation of the piezoelectric membrance by vibration during a blast, a high to low impedance converter connected to the piezoelectric membrane for converting the high output impedance of the piezoelectric membrane into a low impedance signal for transmission through long cables to recording equipment, and means for encapsulating the piezoelectric transducer and converter into epoxy or other solid material to minimize response of the transducer to surrounding acoustic signals.

Accelerometer for blast monitoring

An ultrasonic mine survey probe is disclosed for providing quantitative profile data in cylindrical coordinates of mine stopes, caves and other underground openings. The probe comprises a probe body adapted to be lowered at several vertical positions in an underground opening and containing a non-rotating transducer assembly adapted to generate a beam of ultrasonic energy longitudinally in the probe body, a beam focussing assembly for focussing the beam of ultrasonic energy generated by the transducer assembly, a beam reflecting device for directing the focussed beam of ultrasonic energy radially outward from the probe body toward the wall of the underground opening during transmission and to redirect the echo signals from the wall of the underground opening toward the transducer assembly. The probe body further contains means for moving the beam deflecting device at predetermined angular positions over a 360.degree. scan range at each vertical position of the probe body, and a north orientation seeker for starting all measurement scans at the same angular direction at all vertical positions of the probe body.

Ultrasonic mine survey probe

A metal surface temperature monitor is disclosed. The monitor comprises a rotating sensor head including two wheels fabricated from thermocouple materials and adapted to ride on the surface of the metal to measure the temperature thereof, a converter for converting the thermal EMF generated by the thermocouple to a low frequency coded signal, a transformer having a stationary primary winding and a secondary winding which is free to rotate with the sensor head, a modulating circuit associated with the primary and secondary windings of the transformer for transferring the frequency coded signal from the secondary to the primary winding of the transformer, and means connected to the primary winding of the transformer for demodulating the frequency coded signal to provide an indication of the temperature of the moving metal surface.

Metal surface temperature monitor

An apparatus for measuring bath temperature of metallurgical furnaces through a tuyere is disclosed. The apparatus comprises a periscope adapted to be inserted into a tuyere, a fiber optic cable having one end connected to the periscope for receiving radiation entering the tuyere from the bath of a furnace, and a two wavelength pyrometer connected to the other end of the fiber optic cable for analysing the radiations transmitted through the fiber optic cable to provide an indication of the temperature of the bath.

Tuyere pyrometer

A voltage monitor is disclosed. The voltage monitor comprises a digital voltmeter for displaying a measured input voltage, and means for converting the varying input voltage of the monitor into a stabilized power supply voltage for the operation of the digital voltmeter. The input voltage is applied to the digital voltmeter through a response time controller providing a long time constant averaging value of input voltage to the digital voltmeter when the input voltage is within a predetermined range about a normal value, and for providing a faster response to input voltage values when the input voltage exceeds its normal value. The voltage is also applied to a stability indicator through an averaging circuit which permits the stability indicator to show short term fluctuations of input voltage about its normal value.

Voltage monitor

An oxygen monitoring circuit is disclosed. The circuit comprises a high impedance follow and hold circuit adapted for connection to an oxygen probe, a readout unit connected to the high impedance follow and hold circuit, a programmer normally connecting the oxygen probe to the high impedance follow and hold circuit but momentarily disconnecting the oxygen probe from the high impedance follow and hold circuit for a relatively short time interval and loading it with a resistor having an impedance relatively higher than the normal impedance of the probe, and a probe failure indicator connected to the outputs of the oxygen probe and of the high impedance follow and hold circuit for detecting any significant change in impedance of the probe and resistor combination as a result of loading and for operating an alarm when the impedance of the probe exceeds a predetermined value.

Oxygen monitoring circuit with built in testing means

An apparatus for detecting the presence of a specific substance in a gas stream is disclosed. The apparatus comprises a sensing chamber adapted to receive a test paper which is subject to coloration when contacted by a specific substance in a gas contained in the sensing chamber, means for generating a light beam and directing it toward the test paper in the sensing chamber, a light beam sensing device responsive to the extent to which the test paper in the sensing chamber undergoes coloration in response to exposure to the specific substance in the gas stream, an amplifier connected to the light beam sensing device for providing an output voltage which is proportional to the coloration of the test paper, and means connected to the amplifier for providing an output signal which is an instantaneous indication of the concentration of the substance to be monitored, comprising a signal conditioning circuit connected to the amplifier for providing an output which is a linear function of the cumulative amount of the substance to be detected contacting the test paper, and a differentiator responsive to the output of said amplifier for deriving the instantaneous concentration of the substance in the gas stream. The apparatus is further provided with a beam splitter for dividing the light beam into two separate beams, one directed toward the test paper in the sensing chamber and the other toward a variable optical density filter, and a second light beam sensing device responsive to the transmittance of the variable optical density filter. The amplifier is responsive to the two light beam sensing devices for providing an output which is a function of the ratio of the light sensed by the two light sensing devices irrespective of the light source intensity variations. An automatic zero adjustment device is also provided for resetting the output of the amplifier to zero prior to taking measurements.

Apparatus for detecting the presence of a specific substance in a gas

A magnetic testing device for detecting defects in elongated objects is disclosed. The testing device comprises a permanent magnet assembly having poles adapted to be spaced apart in the longitudinal direction of an elongated object for inducing a longitudinal magnetic flux in a section of the object between the poles of the magnet assembly which is strong enough to saturate such section of the object, a tubular pole piece substantially centered on the elongated object adjacent each pole of the permanent magnet assembly for directing the magnetic flux radially into the object at one pole and out of the object at the other pole, Hall effect devices spaced around at least one pole piece in the path of the magnetic flux for sensing the radial flux entering into the elongated object, and means for sensing the variations of such magnetic flux as an indication of loss of metallic area in the object. The magnetic testing device is also provided with a leakage flux sensor located between the pole pieces for detecting external and internal defects in the object.

Magnetic testing device for detecting loss of metallic area and internal

A froth level monitor is disclosed. The froth level monitor comprises a plurality of electrically conductive electrodes spaced in the vertical direction and adapted to contact the top of the froth in sequence as the level of the froth rises, a constant current source connected to each electrode and capable of generating a constant current when its associated electrode is in contact with the froth, and a summing and time averaging current to voltage converter connected to the output of all the constant current sources for summing up all the currents as an indication of the number of electrodes in contact with the froth and for averaging with respect to time the variations in froth level so as to provide an indication of the mean level of the froth.

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Montreal, Canada

Frank Kitzinger