Abstract: A sensor element is provided for gas sensors, in particular to determine particles in gas mixtures, the sensor element including at least one electrochemical measuring element exposed to the gas mixture to be determined, and at least one temperature-measuring element integrated into the sensor element. The temperature-measuring element includes a resistor track, which has an electric resistance of less than 180 Ohm at 0° C. The resistor track may thus be produced by thin-foil technology, such as screen printing, for example.

Abstract: A knock sensor signal is converted by an A/D conversion part in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from an output signal of the knock sensor and the time-varying patterns of vibration intensity of multiple frequency ranges are extracted. Contours of the time-varying patterns of vibration intensity in multiple frequency ranges are extracted. Vectors indicating directions along which the vibration intensities vary are approximated by the contour of the time-varying pattern of vibration intensity in each frequency range according to the least-squares method. A knock determination is executed based on whether directions of any two or more of multiple vectors are within a predetermined range. Alternatively, a knock determination is executed based on whether a ratio of length of any two or more of the vectors is within a predetermined range.

Abstract: An improved test setup facility, referred to as a “Quick Development Cell” (QDC), which allows for rapid turnaround testing with valuable feedback to a design engineer. Because the QDC allows for quick and efficient testing at a sufficient frequency, QDC tests are compatible with production quality control. In addition to fostering improvement of the API's Section 2 type tests using stressed natural rock for benchmark experiments, the QDC tests allow for progress to be made towards the development of a flow-optimized shape charge and superior well performance.

Abstract: A method and apparatus for determining oil degradation measures a first electric-current value of a driving current used to operate an electric oil pump at a predetermined consistent revolution, and stores the first electric-current value as an electric-current initial value. Data is corrected by measuring a second electric-current value of the driving current, with the second electric-current value being measured when the electric pump is operated at the predetermined consistent revolution when the engine is driven a predetermined time after the electric-current initial value is stored. The electric-current initial value is compared with the second electric-current value. It is then determined that a viscosity of the oil has become low when a difference between the electric-current initial value and the second electric-current value is equal to or greater than a predetermined value.

Abstract: The invention relates to a method of and a device for monitoring the operation of a flotation cell. In the method according to the invention, the electrical conductivity of the material (3, 7) in the flotation cell (1) is measured to observe any variations in the movement, the properties and/or the inner structure of the material. The device (10) according to the invention comprises a number of measuring sensors (11, 12, 13, 14) of electrical conductivity, which are to be fitted in the flotation cell (1) and embedded in the material (3, 7) contained in it for measuring its electrical conductivity and, on the basis of the conductivity values, defining the state and/or the properties of the material.

Abstract: Methods and devices are provided for overcoming detrimental diffusive effects in a sample liquid stream by forming segmented liquid bodies (e.g., droplets) from a sample liquid stream in an immiscible liquid stream. The liquid bodies are formed at the intersection of a channel providing the sample liquid stream and a channel providing the immiscible liquid stream. The formed liquid bodies compartmentalize the portion of the sample liquid stream from which the liquid bodies are formed, thus minimizing the detrimental effects of diffusion that occur in a continuous liquid stream.

Abstract: A device is displayed for determining an organic and inorganic fraction of a sample, which comprises a suspension medium, particularly water, and also solids. A preferably tightly sealable treatment chamber is provided, which comprises a sampling device, a filter unit, which is constructed and attached to the sampling device such that the suspension medium can be removed from the sample through the filter unit, a suction device for removing the suspension medium, a heat energy source for supplying heat energy to the sample, a temperature measuring unit for recording the temperature of the sample, a weighing unit for weighing the sample and a control and data evaluation unit, for controlling the energy source and for receiving and storing output signals from the temperature measuring unit and also the weighing unit. All parts of the device are constructed so that a sample can be analysed within the treatment chamber, without having to remove it in the interim. This represents a considerable time saving.

Abstract: A method of transmitting information making it possible to monitor the operation of an internal combustion engine, includes the steps of: measuring the angular position of a crankshaft via an absolute position sensor provided with a digital output, and transmitting at a frequency f1 to an engine control unit the measured angular position information, encoded in a data string containing N1 bits, transmitting at a frequency f2 of the measured angular position information, encoded in a data string containing N2 bits, the number N2 of bits being greater than the number N1, the frequency f2 being less than or equal to the frequency f1. The encoding in N1 bits allows transmission of angular position information at low resolution, whereas the encoding in N2 bits allows the transmission of high resolution information, able to detect misfirings.

Abstract: Exhaust-gas sensors that have a sensor element, which is surrounded by two protective tubes on a side facing the exhaust gas and which is additionally protected by a porous fiber package, are already known. The fiber package is disposed between the two protective tubes and is meant to protect the sensor element from thermal shock by water droplets hitting the sensor element. When the exhaust gas sensor is used as primary catalytic converter or raw emission sensor, the sensor element can get damaged by sulfur compounds contained in the exhaust gas. In the exhaust-gas sensor according to the invention, damage to the sensor element by exhaust-gas components contained in the exhaust gas is reliably prevented. According to the invention, the adsorption means is implemented in such a way that sulfur, phosphorus or silicon compounds are trapped irreversibly.

Abstract: A test system and method includes a platform having a movable endless belt. A test article is disposed on the belt has wheel assemblies rotated by the endless belt. At least one strut has a first end coupled to the test article and a second end configured to engage the belt as it moves so as to transfer force between belt and the test article.

Abstract: A test device includes a trainline connector for connecting the test device to a car trainline to which the electropneumatic brake device is connected and includes a power port to receive power for the trainline at a first voltage. A power switch selectively connects the power port to the trainline connector. A test switch selectively connects a test voltage smaller than the first voltage to the trainline connector. A sensor senses an electrical parameter of the trainline. A controller a) initially controls the power switch to disconnect the power port from the trainline connector, b) subsequently controls the test switch to connect the test voltage to the trainline connector and c) if the sensor senses an electrical parameter indicative of an acceptable trainline, controls the test switch to disconnect the test voltage from the trainline connector and controlling the power switch to connect the power port to the trainline connector.

Abstract: A brake wear measurement apparatus for use on a brake assembly equipped with a wear pin having a plunger slidably mounted in the plunger sleeve having a first end and second end and wherein when the brake wear measurement apparatus is placed over the wear pin, the wear pin contacts the plunger first end, and moves the plunger within the plunger sleeve to a retracted position corresponding to a retraction distance delta, and wherein the retraction distance delta corresponds to a wear pin exposed height indicating an amount of brake wear. A locking mechanism for locking the plunger in the retracted position may be provided. A brake wear correlation program whereby the input of a brake part number, a plunger retraction distance delta, and a number of performed landings will result in an output of an estimated number of remaining landings may also be provided.

Abstract: The present invention provides an acoustic capacity measurement method for finding capacity of a container or object by removing effect of the surface area without using an approximate expression of acoustic impedance.

Abstract: A test system that is capable of evaluating the effectiveness of a weapons system designed to defeat an incoming, fast-moving, underwater munition is disclosed. In the illustrative embodiment, an extremely large tubular sheath is inflated underwater. The sheath is maintained at a depth and inclination that is appropriate for an incoming torpedo. An inert projectile is launched or flown inside the sheath at a speed that is consistent with the speed of munition that the weapons system is intended to defeat.

Abstract: The present invention provides a simplified anemoscope that allows the direction and intensity of the wind to be relatively accurately confirmed in a simple manner, and that is superior in portability and design. A simplified anemoscope according to the present invention allows the direction and/or intensity of the wind to be confirmed by squirting out a powder or liquid material. The simplified anemoscope includes: a hollow section loaded with the powder or liquid material, and having at least one pore sized to allow the powder or liquid material to be squirted out; and a push-out section for pushing out the air in the hollow section.

Abstract: The static pressure, the differential pressure, and the temperature must be known in order to be able to determine the mass flow rate, the volumetric flow under standard conditions, or the enthalpy flow of a fluid. According to the invention, said variables are detected by individual sensors located in an integrated unit, and the values detected by the individual sensors are then processed in an arithmetic unit that is also integrated. Said sensor unit outputs a value which also takes other parameters and/or physical constants into account to a control unit that is connected downstream, whereby some of the computing is advantageously done in the sensor unit while some load is relieved from the control unit.

Abstract: An ultrasonic-based or radar-based apparatus and method for fuel inventory measurements and for the detection and characterization of materials in a fuel tank, including sludge, water, microorganisms and materials of different viscosities and densities that are present in the tank, presented in an easy-to-interpret picture display that can be remotely located from the tank.

Abstract: A barometric-pressure-sensor device for a portable electronic device, having a pressure sensor of a MEMS type designed to supply a barometric-pressure measurement, and with a processing circuit coupled to the pressure sensor that is designed to supply an altitude measurement as a function of the barometric-pressure measurement. The pressure sensor and the processing circuit are integrated in a single chip, and the processing circuit is a dedicated circuit of a purely hardware type. The processing circuit executes altimeter-setting operations through a plurality of reference registers containing respective pressure references.

Abstract: A measurement system includes a preexisting sensor, a transducer module installed in the pre-existing sensor including a memory storing information for identifying and operating the transducer, and a control device for communicating with the memory, the control device including a processor for automatically configuring the control device in response to data communicated from the memory and for collecting data from the pre-existing sensor. A method includes installing a transducer module into a preexisting sensor, and communicating between a memory of the transducer and a control device to automatically configure the control device in response to information for identifying and operating the transducer stored in the memory, and for collecting data from the pre-existing sensor.

Abstract: A detector and detection method for identifying unknown chemical solutions following chemical spills includes a specific gravity detector including a detector column having an inlet end operable to collect a sample of a solution, wherein the detector column is formed of an optically transparent material to allow visual observation of the sample in the detector column. At least a first plurality of specific gravity floats including a first specific gravity float is located and moveable within the detector column, wherein the first specific gravity float has a density to float in liquids having a specific gravity of greater than a first density level. At least a second specific gravity float is located and moveable within the detector column, wherein the second specific gravity float has a density to float in liquids having a specific gravity greater than the first density level. A sample of an unknown solution from a site of a chemical spill is introduced into the detector column.

Abstract: A physical quantity measuring apparatus includes an oscillation drive circuit that forms an oscillation loop together with a physical quantity transducer and excites a drive oscillation of the physical quantity transducer, and a detection circuit that detects an analog detection signal outputted from the physical quantity transducer using a detection circuit first and thence converts the signal that has been detected into a digital signal using an A/D converter to output the digital signal. The oscillation drive circuit has a drive amplitude detection circuit that detects amplitude of the drive oscillation. A voltage level of a reference of the A/D converter included in the detection circuit is controlled on the basis of a detection output signal of the drive amplitude detection circuit.

Abstract: The invention relates to a method of determining the texture of food material, comprising the steps of applying a vibrational impact with a predetermined frequency to the food material, measuring the vibrational response of the food material to the vibrational impact, and comparing the vibratiorial response with at least one reference value, determined prior to the measurement. The food material is in a liquid or a semi-solid state and/or contained within a container body (16), such as a pipe.

Abstract: A method for measuring an amount of a sublimate in real time with respect to a lapse of heating time, comprising: adhering the sublimate from a thermoset film during heating to a surface of a crystal oscillator using a nozzle inserted into a detection part; and measuring the amount of the sublimate from a change in a resonance frequency corresponding to the amount of the sublimate adhered to the crystal oscillator. In the method, the thermoset film may be formed on a silicon wafer and the measurement is performed while the thermoset film is heated by a heat source disposed under the silicon wafer; or the sublimate may be set so as to flow together with an airstream ascending toward an upper part of an enclosure covering the thermoset film, and the airstream directly contacts the crystal oscillator through the nozzle inserted into the detection part disposed in the path of the airstream.

Abstract: A sensing apparatus utilizing film bulk acoustic resonators (FBARs). The film bulk acoustic resonator has a bulk acoustic wave velocity (Vb) and a corresponding resonant frequency (f). When the FBAR is subjected to a force such as acceleration, g-force or an air pressure, the bulk acoustic wave velocity changes to obtain a frequency downshift (?f) in response to deformation caused by the force. A magnitude of the force is then obtained by calculating the frequency downshift (?f).

Abstract: Sensors affixed to various such structures, where the sensors can withstand, remain affixed, and operate while undergoing both cryogenic temperatures and high vibrations. In particular, piezoelectric single crystal transducers are utilized, and these sensors are coupled to the structure via a low temperature, heat cured epoxy. This allows the transducers to monitor the structure while the engine is operating, even despite the harsh operating conditions. Aspects of the invention thus allow for real time monitoring and analysis of structures that operate in conditions that previously did not permit such analysis. A further aspect of the invention relates to use of piezoelectric single crystal transducers. In particular, use of such transducers allows the same elements to be used as both sensors and actuators.

Abstract: One subject of the invention is a process for checking the robustness of a particulate filter intended to be used in the exhaust line of a diesel engine, comprising the steps consisting in, having first determined the soot mass limit of said filter, loading a new filter with a level of soot at least equal to two times and at most equal to three times said soot mass limit, then making said filter undergo a severe regeneration then, in any order, determining the filtration efficiency of said filter, measuring its pressure drop and comparing it to the pressure drop of the new filter, measuring its level of cracking, and finally checking its integrity after a mechanical stress. Another subject of the invention is a method for diagnosing the robustness of a filter.

Abstract: The ultrasonic testing method according to the invention includes the steps of arranging an ultrasonic probe 1 having a plurality of transducers 11 so as to face a tubular test object P, and causing the transducers appropriately selected from the plurality of transducers to transmit and receive ultrasonic waves so that the ultrasonic waves are propagated in the tubular test object in a plurality of different propagation directions, wherein a ultrasonic testing condition by the ultrasonic probe is set so that respective external refraction angles ?r of the ultrasonic waves in the plurality of propagation directions are approximately equivalent and/or respective internal refraction angles ?k of the ultrasonic waves in the plurality of propagation directions are approximately equivalent.

Abstract: A method is described for nondestructive testing of a test body having at least one acoustically anisotropic material area using ultrasound. The method of the invention includes ascertaining or providing directionally specific sound propagation properties which describe an acoustically anisotropic material area; coupling ultrasonic waves into the acoustically anisotropic material area of the test body; receiving ultrasonic waves reflected from an interior of the test body using ultrasonic transducers; and analyzing ultrasonic signals generated by the ultrasonic transducers so that an analysis is performed which is directionally-selective on a basis of directionally-specific sound propagation properties of the anisotropic material.

Abstract: A sensor failure diagnosis device including a control section that generates vibrations by moving a movable component inside a device is provided. The device includes a determining section that determines whether a value related to a vibration amount output from the sensor, which detects the vibrations generated in the device by the control section, falls within a predetermined range and an output section that outputs a result determined by the determining section.

Abstract: A sensor assembly consists of a metallic pressure sensor cap welded to a tubular gland, which integrally forms a sealing edge on its one end opposing the pressure sensor cap side, a housing part, which has an opening formed therein such that the gland can penetrate the same, and a gland nut being turnably supported on a projecting portion of the gland for attaching the sealing edge to a process port. A stepped portion of the sensor cap is welded to a stepped portion of the gland, and the housing part is fixed to the outside surface of the gland in a position between the sensor cap and the sealing edge. Here, the sensor cap has an outer diameter, which is smaller than or equal to an outer diameter of the gland, so that the sensor cap being welded to the gland beforehand can be fitted into the opening of the housing part.

Abstract: Device and method for determining mechanical stresses in a substrate coating has a substrate holder and actuating element configured as a piezoelectric actuator moveable at least partially in relation to the holed. The actuating element mechanically prestresses the substrate by applying an electric starting voltage to the piezoelectric actuator to cause the actuating element to be partially displacement by a predetermined and/or determinable starting displacement relative to the holed. A coating is applied to a deposition area of the substrates and a change in displacement of the actuating element is determined.

Abstract: A piezoelectric measuring element comprises at least one bar with transverse effect which can be used with two conductor technology. Poles comprising the metallisations, electrodes and lines in the measuring element are embodied with one or more piezoelectric bars with transverse effect such that the electric capacitances thereof with respect to the housing are identical. There can be a completely symmetrical design of the poles. A capacitor from one pole to the housing can correspond to the difference in capacitance of both poles to the environment.

Abstract: Apparatus (10) for monitoring changes in the shape of a hollow structure (20) comprises a flexible elongate support (12), which includes several optical fibre strain sensors (14, 16, 18) each arranged to measure strain in the longitudinal direction of the support (12). The strain sensors (14, 16, 18) are spaced in a direction perpendicular to the longitudinal direction of the support and the support is adapted to bear against the inner surface of the hollow structure (20), such that changes in shape of the structure along the longitudinal direction result in generally corresponding changes in shape of the support.

Abstract: The invention relates to a testing device for tube bundle reactors, with a multitude of tubes (22) arranged as a bundle. At least one probe (12) is movably mounted in or on the testing device (10) and has, in particular, a drive (32) for its movement.

Abstract: The measuring system is inserted into the course of a process line and serves for registering at least one measured variable of a medium flowing in the process line. The measuring system includes for such purpose a measuring transducer having a measuring tube serving for conveying medium being measured and a sensor arrangement, which has at least one sensor element reacting primarily to the measured variable to be registered, and which delivers by means of at least one sensor element at least one measurement signal influenced by the measured variable. Further, the measuring system includes a measuring electronics communicating with the measuring transducer and using the at least one measurement signal for producing, at least at times, at least one measured value instantaneously representing the measured variable.

Abstract: A gas flow meter for obtaining flow volume readings in a gas conduit, including sensors mounted upstream and downstream of a flow restriction device on a rotor, the rotor further including at least one more flow restriction device that can be rotated into position relative to the conduit.

Abstract: An operating device for testing torque wrenches is formed with a carrier for fixing a torque wrench to be tested. A transducer is coupled to the head portion of the torque wrench. A grip holder is provided for fixing the grip of the torque wrench and a deflecting mechanism is adapted for generating a torque to the head portion of the torque wrench to be tested. Further on a sliding mechanism is provided for sliding the grip in the grip holder without friction.

Abstract: There is described an apparatus for providing rotary displacement information indicative of the torque applied to a torsion bar which is rotatable relative to a housing, in which the electromagnetic coupling between a transmit aerial fixed relative to the housing and a receive aerial fixed relative to the housing varies in dependence upon first and second resonators fixed to the torsion bar at spaced axial positions. The first and second resonators have respective different resonant frequencies to enable the signal coupled between the transmit aerial and the receive aerial via the first resonator to be distinguished from the signal coupled between the transmit aerial and the receive aerial via the second resonator.

Abstract: A test system includes a platform having a movable endless belt. A restraint is configured to restrain a test article in a selected vertical position relative to the moveable belt. The restraint includes at least a pair of axially rigid supports wherein at least one rigid support is provided on each side of the movable belt and has an end configured to be secured to the test article, and wherein each support extends from a stationary portion, relative to the belt, of the platform over at least a portion of the movable belt.

Abstract: A fluid testing apparatus and associated method include a testing chamber, a filter storage device and a filter transfer mechanism. The testing chamber has a sample volume, a filtrate collection reservoir, an opening between the sample volume and the filtrate collection reservoir, and at least one port into the sample volume. The filter transfer mechanism positions at least one filter in the opening. The opening is closed and a sample fluid, introduced into the port, at least partially fills the sample volume. The sample volume is pressurized and a filtrate of the sample fluid flows from the sample volume, through the filter into the filtrate collection reservoir. The volume of filtrate passing into the filtrate collection reservoir is measured and the sample fluid from sample volume is discharged. The filtrate is discharged from the filtrate collection reservoir, and the filter transfer mechanism removes the filter.

Abstract: Methods of concentrating an analyte that is in liquid and method of detecting an analyte in a liquid are disclosed. Methods of screening a liquid for the presence of an analyte are also disclosed. Processes comprising continuously collecting a sample of fluid throughout the process and analyzing the sample are disclosed as are processes comprising treating ultrafilter membranes. Devices and systems for concentrating an analyte that is in liquid and for screening a liquid for an analyte are disclosed as well as devices and systems for concentrating an analyte from a continuous sample are disclosed.

Abstract: Apparatus for use in measuring properties of media formed from a particulate suspension. The apparatus includes a media sampler coupled to feed pipes to allow media to flowing therethrough to be sampled and a connector for coupling the media sampler to a sensor for sensing properties of the sampled media.

Abstract: A compliant gear assembly for a gear train of an internal combustion engine includes a hub subassembly having a first hub component and a second hub component. The first hub component defines a first axis, and the compliant gear assembly includes a gear ring rotatable relative to the hub subassembly and defining a gear ring axis of rotation. The second hub component is movable relative to the first hub component in a direction normal to the first axis between a first stop position at which the gear ring axis of rotation is co-linear with the first axis and a second stop position at which the gear ring axis of rotation is parallel to but not co-linear with the first axis. A compliance mechanism is coupled between the first hub component and the second hub component and biases the second hub component toward the first stop position.

Abstract: A bicycle transmission shifting device that includes a cable having a portion of the cable attached to a derailleur and also having another portion of the cable attached to a cable drum. Rotation of the cable drum in one direction pulls the cable to move the derailleur to move a bike chain in a first direction to change gears. Rotation of the cable drum in a second direction pulls or releases tension in the cable to move the derailleur to move the bike chain in a second direction to change gears.

Abstract: A shifter for a vehicle transmission has a lever with a base end. A holder holds the base end of the lever rotatably in first and second perpendicular directions. A shaft is coupled to the base end of the lever. A shift-cable connection has a shaft insertion hole and is held swingably by the holder. The shift-cable connection is connectable with a shift cable connected to a transmission. The follower shaft has a distal end connectable with a selection cable connected to the transmission, and is inserted into the shaft insertion hole to allow the distal end to protrude therefrom. Thus, the shaft swings when the lever is tilted in the first direction to press an inner surface of the shaft insertion hole to swing the shift-cable connection, and moves inside and along the shaft insertion hole when the lever is tilted in the second direction.

Abstract: A shift-by-wire shifter system includes a spring biased DTP lever engageable with a shifter lever assembly to move the shifter lever assembly to a park position. A DTP lock assembly secures the DTP lever so that the shifter lever assembly is selectively movable along the shift path during normal operation and releases the DTP lever so that the DTP lever moves the shifter lever assembly to the park position upon the loss of system power. A DTP actuator unlocks the shifter lever assembly and the DPT lock assembly upon the loss of system power so that the DTP lever automatically moves the shifter lever assembly to the park position upon the loss of system power. A power storage device is provided to release power to the DPT actuator upon the loss of system power.

Abstract: A bicycle pedal (1) mounted at the end (3) of a pedal assembly crank arm (5), includes a main body (7) whereon a cyclist's foot is supported while cycling, the pedal (1) being assembled, along a link axis X1, to the crank arm (5). The pedal (1) includes an intermediate pantograph device (11) for assembling the body (7) to the crank arm (5) producing both a variable offset of the foot purchase on the body (7) relative to the link axis X1 to increase the cycling torque, and to direct the body (7) in a plane defined during the rotation of the crank arm over one pedalling cycle. Bicycles equipped with this type of pedal (1) are also disclosed.

Abstract: The disclosure is directed to a process for producing separable iron and titanium oxides from an ore containing titanium oxide and ferric oxide, comprising: (a) forming agglomerates comprising carbon-based materials and the ore, the quantity of carbon of the agglomerates being sufficient for, at an elevated temperature, reducing ferric oxide to ferrous oxide and forming a ferrous oxide-rich molten slag, (b) introducing the agglomerates onto a carbon bed of a moving hearth furnace; (c) heating the agglomerates in the moving hearth furnace to a temperature sufficient for reducing and melting the agglomerates to produce a ferrous oxide-rich molten slag; (d) metallizing the ferrous oxide of the molten slag by reaction of the ferrous oxide and the carbon of the carbon bed at a furnace temperature sufficient for maintaining the slag in a molten state; and (e) solidifying the slag after metallization of the ferrous oxide to form a matrix of titanium oxide-rich slag having a plurality of metallic iron granules distri

Abstract: The invention relates to a method for separating impurities out of slags, dusts, minerals, preparation residues of minerals or of recyclings or remaining substances, subsequently called feed stock. In order to save energy and reduce costs, the inventive method is characterized by the combination of the following features: melting the feed stock containing the impurities; forming a copper melt; bring the feed stock into contact with the copper melt while adding reducing agents, preferably coke and/or coal; vaporizing, if required, existing volatile compounds such as metal chlorides; reducing metals of the feed stock more noble than copper in the copper melt, and; forming a slag with constituents of the feed stock to be purified that is less noble than copper.

Abstract: A process for the leaching of metals from highly oxidized laterite ores. The ore is admixed with an acidic aqueous medium, preferably a solution of sulfuric acid and the resulting mixture is treated with a sulfur reducing agent so as to reduce mineral species containing cobalt, nickel or manganese. The sulfur reducing agent may be an aqueous solution of sulfur dioxide or more preferably the sulfur dioxide is generated in situ by the reduction of alkali metal sulfite salt. The process is conducted at ambient temperature and pressure with the reduced mineral species being dissolved and subsequently recovered.