Resource Dictionary

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Radioactivity
The property of spontaneously emitting alpha, beta or gamma rays by the decay of the nuclei of atoms.
Radon survey
A geochemical survey technique which detects traces of radon gas, a product of radioactivity.
Raise
A secondary or tertiary inclined opening, vertical or near-vertical opening driven upward form a level to connect with the level above, or to explore the ground for a limited distance above one level.
Rake
The trend of an orebody along the direction of its strike.
Ramp
A secondary or tertiary inclined opening, driven to connect levels, usually driven in a downward direction, and used for haulage.
Rare earth elements
Relatively scarce minerals such as niobium and yttrium.
Reagent
A chemical used in the mineral recovery process
Reaming shell
A component of a string of rods used in diamond drilling, it is set with diamonds and placed between the bit and the core barrel to maintain the gauge (or diameter) of the hole.
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, 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
Reconnaissance
A preliminary survey of ground.
Record date
The date by which a shareholder must be registered on the books of a company in order to receive a declared dividend, or to vote on company affairs.
Recovery
The percentage of valuable metal in the ore that is recovered by metallurgical treatment.
Refractory ore
Ore that resists the action of chemical reagents in the normal treatment processes and which may require pressure leaching or other means to effect the full recovery of the valuable minerals.
Regional metamorphism
Metamorphism caused by both the heat of igneous processes and tectonic pressure.
Regulator
Device (wall, door) used to control the volume of air in an air split.
Replacement ore
Ore formed by a process during which certain minerals have passed into solution and have been carried away, while valuable minerals from the solution have been deposited in the place of those removed.
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 three categories of reserves: possible, probable, and proven.
Reserves, possible
Possible ore Ð material for which quantitative estimates are based largely on broad knowledge of the geological characteristics of the deposit and for which there are few samples or measurements.
Reserves, probable
Probable ore Ð 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.
Reserves, proven
Proven ore Ð 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.
Resin bolting
A method of permanent roof support in which steel rods are grouted with resin.
Resistivity survey
A geophysical technique used to measure the resistance of a rock formation to an electric current.
Resource
A Mineral Resource is a concentration or occurrence of natural, solid, inorganic or
fossilized organic material in or on the Earth's crust in such form and quantity and of such
a grade or quality that it has reasonable prospects for economic extraction. The location,
quantity, grade, geological characteristics and continuity of a Mineral Resource are known,
estimated or interpreted from specific geological evidence and knowledge.
Resuing
A method of stoping in narrow-vein deposits whereby the wallrock on one side of the vein is blasted first and then the ore.
Retort
A vessel in which substances are distilled or decomposed by heat.
Retreat mining
A system of robbing pillars in which the robbing line, or line through the faces of the pillars being extracted, retreats from the boundary toward the shaft or mine mouth.
Return
The air or ventilation that has passed through all the working faces of a split.
Return idler
The idler or roller underneath the cover or cover plates on which the conveyor belt rides after the load which it was carrying has been dumped at the head section and starts the return trip toward the foot section.
Reverberatory furnace
A long, flat furnace used to slag gangue minerals and produce a matte.
Rhyolite
A fine-grained, extrusive igneous rock which has the same chemical composition as granite.
Rib samples
Ore taken from rib pillars in a mine to determine metal content.
Rights
In finance, a certified right to purchase treasury shares in stated quantities, prices and time limits; usually negotiable at a price which is related to the prices of the issue represented; also referred to as warrants. Rights and warrants can be bought and sold prior to their expiry date because not all shareholders wish to exercise their rights.
Robbed out area
Describes that part of a mine from which the pillars have been removed.
Rock
Any natural combination of minerals; part of the earth's crust.
Rock factor
The number of cubic meters of a particular rock type required to make up one tonne of the material. One tonne of a highly siliceous ore may occupy 0.40 cubic meters, while a tonne of dense sulfide ore may occupy only 0.25 cubic meters.
Rock mechanics
The study of the mechanical properties of rocks, which includes stress conditions around mine openings and the ability of rocks and underground structures to withstand these stresses.
Rockbolting
The act of supporting openings in rock with steel bolts anchored in holes drilled especially for this purpose.
Rockburst
A violent release of energy resulting in the sudden failure of walls or pillars in a mine, caused by the weight or pressure of the surrounding rocks.
Rocker
A device for washing gold-bearing earth to recover the precious metal.
Rod mill
A rotating steel cylinder that uses steel rods as a means of grinding ore.
Roll
A high place in the bottom or a low place in the top of a mine passage
Roll protection
A framework, safety canopy, or similar protection for the operator when equipment overturns
Roof bolt
A long steel bolt driven into the roof of underground excavations to support the roof, preventing and limiting the extent of roof falls. The unit consists of the bolt (up to 4 feet long), steel plate, expansion shell, and pal nut. The use of roof bolts eliminates the need for timbering by fastening together, or "laminating," several weaker layers of roof strata to build a "beam."
Roof jack
A screw- or pump-type hydraulic extension post made of steel and used as temporary roof support.
Roof sag
The sinking, bending, or curving of the roof, especially in the middle, from weight or pressure.
Roof trusses
A combination of steel rods anchored into the roof to create zones of compression and tension forces and provide better support for weak roof and roof over wide areas.
Room neck
The short passage from the entry into a room.
Room-and-pillar mining
A method of mining flat-lying ore deposits in which the mined-out area, or rooms, are separated by pillars of approximately the same size.
Rotary drill
A machine that drills holes by rotating a rigid, tubular string of drill rods to which is attached a bit. Commonly used for drilling large-diameter blastholes in open-pit mines.
Round
Planned pattern of drill holes fired in sequence in tunneling, shaft sinking, or stopping. First the cut holes are fired, followed by relief, lifter, and rib holes.
Royalty
The payment of a certain stipulated sum on the mineral produced.
Run of mine
Raw material as it exists in the mine; average grade or quality.
Run of mine ore
Uncrushed ore in its natural state just as it is when blasted