decline
A sloping tunnel that winds downward from the surface into an underground mine, wide enough for trucks or conveyor belts to carry ore and equipment in and out.
तकनीकी रूप से: An inclined tunnel driven from surface at a gradient sufficient to allow wheeled or tracked vehicles — typically diesel trucks or, in some operations, conveyor systems — to travel between the surface and underground working levels. Declines provide an alternative to shaft hoisting for accessing orebodies at moderate depth, with the advantage of lower initial capital cost and the flexibility to carry large equipment underground without the constraints of a hoisting conveyance. They are distinguished from adits by their significant downward inclination and from shafts by their drivable, ramp-like geometry. At greater depths, the travel time and fuel cost of trucking up a long decline typically make shaft hoisting more economical, which is why the two access methods are often compared directly in feasibility studies.
Mining
demand destruction
When prices rise so high, or a material becomes so hard to get, that buyers permanently stop using it and find other ways to do without — the demand does not just pause, it disappears.
तकनीकी रूप से: A sustained and typically irreversible reduction in demand for a material resulting from price levels or supply constraints that have induced permanent changes in technology, behaviour or product design. Demand destruction differs from demand suppression, which is a temporary fall in consumption that reverses when conditions normalise; destruction implies that consumers have switched technologies or production processes in ways that do not simply unwind when prices ease. The concept is particularly relevant in minerals markets where prolonged price spikes can accelerate substitution or efficiency improvements that structurally lower the material intensity of key end uses.
Markets
dilution
Dilution is the extra worthless rock that gets mixed in with the ore when a mine is blasted and dug. The more dilution there is, the lower the overall grade of the material sent to the processing plant.
तकनीकी रूप से: Dilution is the reduction in average grade of mined material caused by the incorporation of sub-cut-off-grade or waste rock into the ore stream during extraction. It is commonly expressed as the proportion of waste included in the ore parcel by mass or volume. Dilution is distinguished between planned dilution — unavoidable waste inclusion accounted for in the mine design — and unplanned dilution, which reflects over-break, wall sloughing or poor grade control. High dilution increases milling costs per unit of recovered metal and reduces head grade, directly affecting process economics.
Mining
doré
A rough bar of mixed gold and silver, still containing impurities, poured at a mine before being sent to a refinery to be separated and purified into pure metals.
तकनीकी रूप से: Doré is an unrefined alloy of gold and silver, typically cast as bars at the mine or smelter following the processing of ore through leaching, gravity concentration, or pyrometallurgical routes. Its composition varies widely depending on the ore source, and it commonly contains minor quantities of base metals, sulfur compounds, and other impurities. Doré is the standard form in which gold and silver leave most mine sites for delivery to an independent bullion refinery, where the two precious metals are separated and brought to commercial purity; it is therefore a mine product and a refinery feed rather than a finished metal, and its value is assessed on the basis of assayed precious-metal content less refining charges.
Processing
drill hole
A drill hole is a narrow hole bored into the ground by a drilling machine, used to bring up samples of rock from deep underground so geologists can study what is there.
तकनीकी रूप से: A drill hole is a borehole created by a drilling rig for the purpose of geological investigation, resource definition, geotechnical assessment, or hydrogeological testing; it is defined by its collar coordinates, azimuth, dip, and total depth, all of which must be surveyed to enable accurate three-dimensional plotting. In resource reporting, each drill hole is assigned a unique identifier, and its downhole survey data are used to reconstruct the actual path of the hole, which deviates from a straight line in most cases. Drill hole is the preferred term in technical reporting over the informal borehole when the context is mineral exploration, though the two are sometimes used interchangeably.
Geology
due diligence
Checking carefully where a material came from and whether anything harmful happened along the way before it reached you — like inspecting something thoroughly before you accept it.
तकनीकी रूप से: A structured process by which a company identifies, assesses and addresses actual or potential risks in its mineral supply chain, including risks relating to conflict financing, human rights abuses, environmental violations and sanctions exposure. In the minerals context, due diligence frameworks — such as those published by the OECD — specify documentation, traceability and audit requirements at each stage of the chain from mine to market. Due diligence describes the process of investigation and risk management, and should not be treated as equivalent to certification, which is the outcome that third-party audit programmes may confer once due diligence has been satisfactorily completed.
Markets