Mining-Prospecting Dictionary

• R aise: A vertical hole between mine levels used to move ore or waste rock or to provide ventilation.
• Ramp: An underground tunnel providing access for exploration or the movement of materials and equipment between mine levels.
• Ramp: An inclined underground tunnel which provides access for exploration or a connection between levels of a mine.
• Reaming: Enlarging the diameter of a hole.
• Recovery: The rate and amount of valuable minerals processed and extracted from a placer deposit.
• Recovery Rate: The percentage of metals recovered in a mineral separation process. Recovery rates vary considerably depending on physical, metallurgical and economic circumstances.
• Reclamation: The process by which lands disturbed as a result of mining activity are reclaimed back to a beneficial land use. Reclamation activity includes the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetation of waste rock piles and other disturbed areas.
• Recovery rate: A term used in process metallurgy to indicate the proportion of valuable material obtained in the processing of an ore. It is generally stated as a percentage of the material recovered compared to the total material present.
• Refining: Extracting and purifying metals and minerals. A process of removing impurities from metals by introducing air and fluxes into the molten metal. The impurities are removed as gases or slag.
• Refractory material: Gold mineralized material in which the gold is not amenable to recovery by conventional cyanide methods without any pre-treatment. The refractory nature can be either silica or sulphide encapsulation of the gold or the presence of naturally occurring carbons which reduce gold recovery.
• Reserves: That part of a mineral deposit which could be economically and legally extracted or produced at the time of the reserve determination. Reserves are customarily stated in terms of ore when dealing with metalliferous minerals. There are two categories of reserves: Proven Ore: Material for which tonnage and grade are computed from dimensions revealed in outcrops, trenches, underground workings or drill holes; grade is computed from the results of adequate sampling; and the sites for inspection, sampling and measurement are so spaced and the geological character so well-defined that size, shape and mineral content are established. Probable Ore: Material for which tonnage and grade are computed partly from specific measurements, samples or production data and partly from projection for a reasonable distance on geological evidence: and for which the sites available for inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely or to establish its grade throughout
• Residual: Left over; eroded in place.
• Resource/mineralized Material: Mineralization based on geological evidence and assumed continuity. May or may not be supported by samples but is supported by geological, geochemic al, geophysical or other data.
• Restrike: A modern replica of previously issued coins. Governments and their mints can choose to "restrike" a previous issue rather than introduce new coinage.
• Reverse Circulation Drilling: Drilling that produces rock chips rather than core. Faster and cheaper than diamond drilling, the chips are forced by air to surface for examination.
• Reverse Circulation Holes: Holes drilled using a process where the circulation of bit-coolant and cuttings-removal liquids, drilling fluid, mud, air, or gas down the borehole outside the drill rods and upward inside the drill rods. Also called countercurrent; counter flush.
• Reverse-Slip: An area that has dipped toward the block that has been relatively raised.
• Rime: A groove or ridge in the bottom of a stream channel; a slat or block of wood or metal placed across a sluice box or other placer unit.
• Roast: To heat an ore to drive off volatile substances or oxidize the ore.
• Roasting: The treatment of ore by heat and air, or oxygen enriched air, in order to remove sulphur, carbon, antimony and arsenic.
• Room & pillar: A mining method for underground mines where most of the rock is removed and pillars are left intact to provide roof support.
• Run-of-Mine Ore: Uncrushed ore in its natural state just as it is when blasted.
• Rhyolite: A group of extrusive, igneous rocks.