offtake agreement
A long-term promise by a buyer to purchase a set amount of a material from a mine or plant, often signed before the mine is even built, to give the producer confidence it will have a customer.
技术层面: An offtake agreement is a commercial contract in which a buyer commits to purchase a defined volume or share of a project's output over a specified period, typically at a price linked to a market reference at the time of delivery rather than fixed in advance. Such agreements are commonly used to underpin project financing, since the guaranteed revenue stream reduces lender risk. Key variables include the volume commitment (which may be a floor, a ceiling or a percentage of production), the pricing formula, the treatment and refining charges deducted for concentrates, and the conditions under which either party may terminate or renegotiate.
Markets
open pit
A mine that works in the open air by digging a giant bowl-shaped hole in the ground, removing rock layer by layer from the top down.
技术层面: A surface mining method in which mineralised rock is extracted from an open excavation, typically stepped into a series of descending benches, without any underground workings. The method is chosen when the orebody is broad, relatively shallow, and the strip ratio — the volume of waste rock that must be moved per unit of ore — remains economically acceptable at the planned depth. It is sometimes called open-cut or open-cast mining, though open-cast more precisely refers to the excavation of shallow, flat-lying deposits where the original surface is later restored.
Mining
opex
The money a mine or factory spends to keep running day to day — wages, fuel, chemicals and so on — as opposed to the big one-off costs of building it in the first place.
技术层面: Operating expenditure covers all costs incurred in the ongoing production process: labour, energy, reagents, maintenance consumables and site-level administration. It is distinguished from capital expenditure (capex), which funds assets with a working life extending beyond the accounting period. In mine-cost analysis, opex is often expressed per unit of output — per tonne milled or per pound of metal produced — making it the primary basis for comparing operational efficiency across sites.
Markets
ore
Rock that contains enough of a useful mineral to be worth digging up and processing. Rock with the same mineral but too little of it is just rock.
技术层面: Ore is rock or sediment from which one or more commodities can be extracted at a profit under the prevailing economic and technical conditions. The classification is economic, not purely geological: the same material can be ore at one metal price and waste at another. It is often confused with 'mineral', which refers to a specific chemical compound regardless of whether its occurrence is economically exploitable.
Geology
orebody
A distinct mass of ore in the ground with a recognisable shape — like a thick underground blob or sheet of valuable rock that has been mapped out.
技术层面: An orebody is a continuous, three-dimensionally defined volume of rock that meets the criteria for ore and is sufficiently coherent in geometry and grade to be treated as a discrete extraction target. The term implies that the boundaries have been established by drilling or sampling, distinguishing it from a mere mineralised occurrence or prospect. A single deposit may contain several separate orebodies if high-grade zones are separated by material that does not meet cut-off grade.
Geology
outcrop
A place where solid bedrock is exposed at the surface, not covered by soil, loose sediment, or vegetation — the rock you can walk up to and touch.
技术层面: An outcrop is any exposure of in-situ bedrock or mineralisation at the Earth's surface, whether natural (erosion, cliff face, stream cut) or artificial (road cut, quarry face). In field mapping and early-stage exploration, outcrop is significant because it allows direct sampling and observation without drilling or trenching. The extent of outcrop should not be equated with the extent of the underlying unit, since the same rock body may extend considerable distances beneath cover; conversely, an apparently continuous outcrop may be interrupted by faulting that is invisible from the surface.
Geology
overburden
All the soil, loose rock, and waste material sitting on top of a mineral deposit that has to be moved out of the way before mining can begin.
技术层面: Overburden refers to the mass of rock, regolith, and soil overlying an orebody or target stratum that must be stripped or excavated to gain access to the material of interest, particularly in surface mining. The ratio of overburden volume to ore volume (the strip ratio) is a primary determinant of the economics of open-pit and strip mining. In some technical contexts, particularly in sedimentary basin studies, the term is used more broadly to denote any overlying rock sequence regardless of mining context, which can cause ambiguity; the intended meaning should be clear from context.
Geology
oxide equivalent
A way of describing how much of a metal is present by pretending it has all been turned into its oxide form, even if it is actually in the ground as a different compound.
技术层面: Oxide equivalent is a reporting convention in which the quantity of a metal or suite of metals is expressed as the mass of the corresponding oxide or oxides that would be formed if all the metal were fully oxidised. It is standard in rare-earth reporting, where individual elements are reported as their trioxides (e.g. La₂O₃, CeO₂) and totals are summed as total rare earth oxide. Because oxide equivalent inflates mass relative to contained metal by a factor that varies by element, it cannot be compared directly with contained-metal figures without applying the appropriate elemental conversion factor.
Materials