Abstract: A dust control system for a mining machine, particularly for controlling respirable dust in coal mining operations, comprising a ductwork system having intakes adjacent the cutter head of the mining machine, a fan for drawing air through the ductwork system, a flooded bed scrubber in the ductwork system upstream from the fan for entraining dust, including respirable dust, in the air in droplets of water, air flowing through the scrubber carrying the dust-laden droplets of water downstream from the scrubber, a sump below the ductwork system between the flooded bed scrubber and the fan, a demister in the ductwork system above the sump for separating the dust-laden droplets of water and directing them into the sump, and a pump for pumping the dust-laden water from the sump to a point adjacent the cutting head. A method of controlling dust is also disclosed.

Abstract: Apparatus for and method of controlling the mining by a mining machine of a seam of material (e.g., coal) overlying or underlying a stratum of undesired material (e.g., clay) to reduce the quantity of undesired material mined with the desired material, the machine comprising a cutter movable up and down and adapted to cut down into a seam of coal on being lowered. The control apparatus comprises a first electrical signal constituting a slow-down signal adapted to be automatically operated to signal when the cutter has cut down into a seam of desired material generally to a predetermined depth short of the interface between the seam and the underlying stratum for slowing down the cutting rate as the cutter approaches the interface, and a second electrical signal adapted to be automatically operated subsequent to the first signal for signalling when the cutter has cut down through the seam to the interface for stopping the cutting operation, thereby to avoid mining undesired material with the desired material.

Abstract: A mine roof-bolter machine having an extensible conveyor running therethrough operates behind a continuous miner machine. As the continuous miner advances, the roof-bolter advances from position-to-position while installing roof bolts and plates, and the extensible conveyor gives and takes the slack between the continuous miner and the roof bolter and feeds mined material to a surge car behind the roof bolter.

Abstract: Connected support sections for a mineral face conveyor are individually supported on the forward sides of chocks which move in towards the rib of a panel behind a mining machine. Backfill is transported to the mined area behind the moved-up chocks via a conveyor supported from connected support sections on the rear sides of the chocks.

Abstract: An articulated ancillary support for a conveyor is attached onto the forward side of a mine roof chock by extensible means which, when retracted towards the chock, shifts the ancillary support from a normal condition in which it occupies an area of relatively wide lateral extent to another condition in which it overlies an area of relatively narrow lateral extent, freeing a large portion of the space under the chocks to clear the way for a retreating continuous miner.

Abstract: A downhole recirculator for injecting two-phase lixiviant from a tubing string into a leaching interval of an in situ mine field injection hole, and for circulating the injected lixiviant within the leaching interval. The recirculator includes a core device which is adapted to be readily inserted or removed from its operating position in a fixture defining the upper limit of the leaching interval. The core device includes an induction valve arrangement whereby a primary flow of two-phase lixiviant supplied from the minefield surface by way of the tubing string induces a secondary flow of lixiviant from regions of the injection hole near the top of the leaching interval. The primary flow two-phase lixiviant is combined with the secondary flow lixiviant and injected to a region near the bottom of the leaching interval to establish a circulatory motion of lixiviant within the leaching interval.

Abstract: Refractory metal pickling bath of HF/H2O2 aqueous solution with recovery of the etched metal as a salt thereof and separation of dissolved impurities taken from the refractory metal, with avoidance of drawbacks of state of the art HF/HNO3 pickling solutions.