| Aquifer |
The place where one can find useful quantities of groundwater. Typically refers to a particular type of porous rock or soil, such as sandstone. |
| Barren Solution |
A solution in hydrometallurgical treatment from which all possible valuable constituents have been removed. |
| Bleed Solution |
Solution drawn to adjust production or to restore groundwater by pumping more fluids from the production zone than are injected, creating an inflow of fresh groundwater into the production area. |
| Brine Solution |
A concentrated solution containing dissolved minerals (usually greater than 100,000 mg/liter), especially chloride salts. |
| Elution |
Activities of removing "elutes" a material (uranium) adsorbed on ion exchange resin from the "eluant" solution. |
| Evaporation Pond |
A containment pond (that should have an impermeable lining of clay or synthetic material such as hypalon) to hold liquid wastes and to concentrate the waste through evaporation. |
Extraction Well
(Production) |
A well or a drill hole in an in situ leach operation through which the solutions (or groundwater) are extracted to the surface treatment plant. Typically surrounded by injection wells. |
| Groundwater |
Water beneath the surface in the saturated zone that is under atmospheric or artesian pressure. |
| Heavy Metals |
Metallic elements, including those required for plant and animal nutrition, in trace concentration but which become toxic at higher concentrations. Examples are mercury (Hg), selenium (Se), molybdenum (Mo), cadmium (Cd), and lead (Pb). |
| In Situ Leaching |
The in-place mining of a mineral without removing overburden or ore, by installing a well and mining directly from the natural deposit thereby exposed to the injection and recovery of a fluid
that causes the leaching, dissolution, or extraction of the mineral. |
| Ion Exchange |
Reversible exchange of ions adsorbed on a mineral or synthetic polymer surface with ions in solution in contact with the surface. A chemical process used for recovery of uranium from solution by the
interchange of ions between a solution and a solid, commonly a resin. |
| Injection Well |
A well or a drill hole in an in situ leach operation through which barren solutions are entered into an underground stratum or ore body by gravity or under pressure. Typically surrounded by monitoring wells. |
| Leachate |
The liquid that has percolated through the soil or other medium. |
| Lixiviant |
Leachate solution pumped underground to a uranium ore body; it may be alkaline or acidic in character. |
| Pachuca Tank |
A cylindrical tank with a conical bottom used in slime leaching. |
| Palaeochannel |
An old river bed formed at a time when the geology and climate of an area was different, with generally higher rainfall. Subsequent changes have seen the river bed, which would be mostly sand and gravels, buried by a further cover sediment. The sands and clays (in minor amounts) are interlayered and are notorious for being highly variable and difficult to characterise. |
| Permeability |
The ease with which fluid flows through a porous medium. |
Porous
(Pore Space) |
The open spaces or voids within a soil or rock. It is a measure of the amount of liquid or
gas that may be absorbed or yielded by a particular formation. |
| Pore Volume |
Volume equal to the open space in rock or soil. |
| Pregnant Solution |
A solution containing dissolved extractable mineral that was leached from the ore;
uranium leach solution pumped up from the under-ground ore zone though a production hole. |
| Radon |
Chemically inert radioactive gaseous element formed from the decay of radium. A potential health hazard. |
| Reverse Osmosis |
The act of reversing a diffusion through a semipermeable membrane, typically separating a solvent and a solution, that tends to equalize their concentrations. |
| Restoration |
The returning of all affected groundwater to its premining quality for its premining use by employing the best practical technology. |
| Roll Front |
A type of uranium deposition localized as a roll or interface separating an oxidized interior from a reduced exterior. The reduced side of this interface is significantly enriched in uranium. |
| Saturated Zone |
The zone of a soil or rock formation where the pore space is completely filled with water. This would be called an aquifer at depth or the water table if immediately below the surface sediments. |
| Solution Mining |
Another term used for In Situ Leaching. |
| Wellfield |
The area of an in situ leach operation that encompasses the array of injection and extraction wells and interconnected piping employed in the leaching process. |