Abstract: The present invention is concerned with a process for the direct smelting of zinc containing materials. The process includes volatilizing zinc from zinc-containing materials into a gas phase, while sulphur is fixed as iron sulphide in a Fe-S-O matte. Thereafter, zinc is recovered in metallic form with a suitable condenser apparatus from a zinc laden gas consisting of Zn(g), CO, CO.sub.2 and N.sub.2. Other metals like silver, cadmium, mercury and lead may also be recovered in this manner.

Abstract: A lime-treatment method is disclosed to neutralize acidic waters containing heavy metals and sulphate and precipitate the metals as hydroxides along with calcium sulphate solids which are called sludge. The method comprises neutralizing the water in two reactors, the pH of the first reactor being increased to 4-4.5 using a predetermined amount of recycled sludge to precipitate only ferric hydroxides whereas other metal hydroxides coming from the recycled sludge are dissolved, the pH of the second reactor being increased to 9-10 using a mixture of lime and a small amount of the sludge recycled to the first reactor; feeding the ferric hydroxides precipitated in the first reactor to the second reactor to act as nuclei in the second reactor to promote crystallization; and introducing air into the second reactor to oxidize ferrous iron to less soluble ferric iron which results in formation of a more stable sludge compared to ferrous sludge.

Abstract: In accordance with the present invention, there is now provided a method for removing asphaltene deposits in a well environment such as the wellbore and near-wellbore regions, comprising the injection of deasphalted oil therein to solubilize the asphaltene deposits obstructing the well environment. More specifically, the method of the invention comprises the injection of deasphalted oil into the wellbore and the near-wellbore formation followed by a soaking period and a production period. The method of the present invention has the great advantage of readily dissolving precipitated asphaltene in a well environment without other costly treatments such as the use of solvents like xylene or toluene. Furthermore, the present method does not require the incorporation of any additives in the deasphalted oil.

Abstract: A method for removing thallium ions from aqueous solutions uses manganese dioxide sludge produced during the electrolysis of zinc. The preferred allotropy of MnO.sub.2 is the .alpha.-form, which selectively absorbs thallium ions with minimum interference from other elements and metal ions present in the solution, and is significantly more economical than other reagents currently used for the same purpose.

Abstract: 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.

Abstract: A method for measuring the three dimensional stress in rock surrounding a borehole comprises the steps of cutting slots into the wall of a borehole at different angles relative to the borehole axis so as to effect stress relaxation and strain deformations which are representative of the stresses normal to the angle of the respective slots, and measuring the respective strain deformations adjacent to the slots that are being cut into the borehole wall at a sufficient number of angles to satisfy the mathematical requirement of six independent equations to solve for the three dimensional stress tensors so as to determine the three dimensional stress field surrounding the borehole from measurements in a single borehole.

Abstract: A process is provided for the recovery of bismuth from an ion exchange eluent solution consisting of at least 50% sulfuric acid maintained at a temperature of 95.degree.-100.degree. C. The process comprises the step of electrowinning bismuth from the sulfuric acid solution in an electrochemical cell at a current density up to 30 A/m.sup.2 using an insoluble anode and a cathode that is impervious to the highly corrosive environment of hot sulfuric acid, for a time interval such as to reduce the bismuth content of the solution down to about 3-5 g/L.

Abstract: A melt-texturing method for producing high transition temperature superconducting ceramic elements of given length, such as wires of Y Ba.sub.2 Cu.sub.3 O.sub.7-.delta., which method is much faster and efficient than the existing ones. In this method, an element made of grains of superconducting ceramic precursor material is subjected to zone melting at a number of different locations equally spaced apart along its length. This multi-zone-melting is carried out at the same time, under the same temperature and speed conditions and in the same direction so as to form a same number of similarly textured zones along the length of the element, which zones grow up while the method progresses until they merge. This method makes it possible to multiply the present rate of production known to be very low, by a number of the same order of magnitude as the number of different locations where zone melting is carried out.

Abstract: A method of increasing the near-wellbore permeability of porous formation comprises exposing formation to an elevated temperature of 400.degree. C. or greater to cause dehydration of the clay lattices, vaporization of any blocked water, mud filtrate or other fluids, and/or destruction of the clay structure.

Abstract: A method of injecting powdered material into converters or other metallurgical vessels equipped with at least one submerged tuyere and a gas flow line interconnecting the tuyere to a bustle pipe or other source for blowing converting gas into the tuyere comprises providing an injection pipe fitted into the tuyere at an acute angle, preferably about 20.degree. C., with respect to the centre line of the tuyere and intersecting the tuyere at a point downstream of the gas line flow line entrance, and introducing fluidized powdered material into the tuyere through such injection pipe.

Abstract: A gravity orientation device comprises a cylindrical casing, a shaft rotatably mounted in the casing along the longitudinal axis thereof and having pointed ends contacting bearing surfaces located in the ends of the casing, an encoder mounted within the casing and having a fixed portion secured to the casing and a rotary portion secured to the shaft, and a weight pendulum mounted on the shaft for rotation around the shaft under the influence of gravity.

Abstract: This invention relates a method for the selective removal of alkali metal salts of sulphate (SO.sub.4.sup.2-), and thiosulphate (S.sub.2 O.sub.3.sup.2-) from hydrogen sulphide (H.sub.2 S) scrubber solutions of the liquid redox type using an electrodialysis system. In the process of this invention the H.sub.2 S scrubber solution is directed to the diluting compartments within an electrodialysis stack, while a collecting solution with a minimal initial salt content is directed to the concentrating compartments. With the application of a direct current a portion of the alkali metal salts of sulphate and thiosulphate present in the scrubber solution are transported through ion selective membranes into the collecting solution. Essentially all of the metal organic chelate reagents and carbonate ions initially present in the scrubber solution are retained in the desalted solution and can be recycled to the H.sub.2 S scrubbing process.

Abstract: An apparatus for measuring the basic friction angle of a surface of given material comprises a housing adapted to be held against a surface of material to be tested, a base which can slide along the inside wall of the housing, a wheel mounted on the lower part of the base and adapted to contact the surface to be tested, a spring for applying a load on the base to force the wheel against the surface to be tested, and a torque gauge for applying a torque to the wheel, and for measuring the maximum torque required to spin the wheel on the surface to be tested at various loads applied to the base.

Abstract: A self-cooling lance or tuyere for the conveying of gases, liquids or solids into or onto a metallurgical bath comprises a heat pipe or thermosiphon made of two tubular members adapted to be immersed in a furnace environment at one end, such tubular members defining a closed annular chamber therebetween for containing a working substance adapted to evaporate in the region of the heat pipe which is in the furnace environment and flow toward the end which is out of the hot environment where it condenses and flows back to the evaporator region. Means are provided for introducing the gases, liquids or solids to be conveyed into the bath through the inner tubular member of the lance.

Abstract: A method of removing zinc from galvanized steel, comprises immersing the galvanized steel in a caustic electrolyte solution, electrically connecting the steel to the positive terminals of a source of direct current, and electrically connecting the negative terminals of the current source to a cathode material which is stable in caustic electrolyte and has a low hydrogen overvoltage.

Abstract: A method of removing zinc from galvanized steel without substantial co-dissolution of substrate iron comprises immersing the galvanized steel in a caustic electrolyte solution, and electrically connecting the galvanized steel to a cathode material which is stable in caustic electrolyte and has a low hydrogen overvoltage.

Abstract: A monitoring unit for installation on a cable bolt comprises a tube designed to fit within a cable bolt hole and having a collar at one end thereof, a cable bolt adapted to be grouted in the rock at the centre of the tube, a base plate placed tightly against the tube collar adjacent the rock face, a centralizer sleeve designed to fit over the cable bolt to keep the cable centralized within the base plate and tube, an elongated measuring plate having a centre hole for insertion of the cable bolt to fit tightly against the base plate and a groove cut at equal distances from each side of the centre hole for allowing the measuring plate to bend if the rock moves with respect to the cable bolt, and a cable clamp for fixing the measuring plate tight against the base plate.

Abstract: A method of increasing the extraction of tellurium from copper electrorefining slime comprises leaching the slime with dilute sulphuric acid in a reactor under a partial oxygen pressure of up to 150 psi and at an elevated temperature between about 100.degree. and 200.degree. C. until copper, nickel and substantially all of the tellurium is dissolved, thereby forming a leach slurry, and contacting the slurry with an appropriate reducing agent immediately after the leaching operation has been halted and the leaching reactor brough back to atmospheric pressure to reprecipitate any excessive quantities of silver and selenium solubilized during the leaching operation.

Abstract: A cavity monitoring system includes a supporting system adapted to be installed in an access leading to a mined stope, or any other cavity, a mast mounted on the supporting system and adapted to extend into the cavity, and a laser rangefinder mounted at the end of the mast. The laser rangefinder is capable of being rotated around the axis of the mast and directed at the wall of the cavity at angles varying from 0 to 145 degrees from the axis of the mast so as to scan concentric circles on the wall of the cavity permitting a series of distance measurements to be taken to obtain the shape and volume of the cavity.

Abstract: A cable grip for improving the performance of cable bolts for ground support comprises a segmented wedge defining a cone, each segment having an inside cavity adapted to conform to a circumference of a cable and serrated grooves cut into said inside cavity to grip the cable, and a sleeve consisting of a plastic cone conforming to the conical shape of the wedge.