Bayer process
The standard industrial method for purifying bauxite ore into alumina powder, using hot caustic soda to dissolve the aluminium and leave the impurities behind.
技术层面: The Bayer process is the dominant commercial route for producing metallurgical-grade alumina from bauxite, comprising four principal stages: digestion of crushed bauxite in hot concentrated sodium hydroxide solution to dissolve aluminium-bearing minerals as sodium aluminate; clarification and washing to separate the insoluble residue (red mud or bauxite residue); precipitation of aluminium hydroxide from the cooled, seeded liquor; and calcination of the hydroxide to anhydrous alumina. The process is selective for gibbsite, boehmite and diaspore but is less effective on silica-rich bauxites because silica reacts with caustic to form desilication products that consume reagent and reduce yield.
Processing
backfill
Backfill is material packed back into the empty spaces left after underground mining. It stops the ground from collapsing and can allow miners to safely dig out the next section nearby.
技术层面: Backfill is any material placed into mined-out stopes or other underground voids to provide ground support and reduce surface subsidence. It is commonly categorised as hydraulic fill (slurried fine material pumped underground), paste fill (thickened tailings with binder), or waste-rock fill. In operations where cemented paste fill is used, the compressive strength of the cured fill is a design parameter that determines how close adjacent stopes may be mined, distinguishing backfill from simple void control into an active structural element.
Mining
banded iron formation
A very ancient layered rock made of alternating stripes of iron-rich minerals and silica, laid down on ancient seafloors long before there was much oxygen in the atmosphere.
技术层面: A banded iron formation (BIF) is a chemically precipitated sedimentary rock characterised by alternating iron-rich layers (typically magnetite or hematite) and silica-rich layers (chert), deposited predominantly in Precambrian marine basins. The banding is thought to reflect periodic changes in ocean chemistry or oxygen availability rather than clastic input. BIFs are the principal source rock for most of the world's iron ore, with economic deposits typically requiring secondary enrichment to raise iron grades to commercially workable levels.
Geology
base metal
The ordinary workhorse metals like copper, lead, zinc, nickel and tin that are mined and used in large quantities for everyday construction and manufacturing.
技术层面: Base metals are those common non-ferrous metals that oxidise or corrode relatively readily when exposed to air or moisture, distinguishing them from precious metals. The group conventionally includes copper, lead, zinc, nickel, tin and aluminium, though precise membership varies by source. They are produced and traded in large volumes, and their prices are tracked as broad indicators of industrial activity. The term is primarily economic and commercial rather than chemical in its usage.
Materials
bench
One of the flat, step-like levels cut into the side of an open pit mine; the mine looks like a giant staircase when viewed from the air.
技术层面: In open pit mining, a bench is a horizontal working level defined by a flat floor and a near-vertical face of rock — the bench face — cut to a specified height. Drilling and blasting are conducted at bench level, and excavation equipment works along the bench floor before the pit is deepened by creating the next bench below. Bench height, face angle, and the width of the horizontal berm between successive benches are determined by a combination of rock mass properties, equipment dimensions, and geotechnical stability requirements. The term is occasionally used in underground mining to describe a stepped working face, but without qualification it refers to an open pit feature.
Mining
benchmark price
A price that big buyers and sellers agree on — often once a year — which then sets the standard that smaller deals in that market copy.
技术层面: A benchmark price is a reference price negotiated between major producers and consumers, historically in annual or quarterly contracts, against which other transactions in the same commodity are priced, often with a small adjustment for grade or location. It is most associated with iron ore and metallurgical coal, where a handful of large counterparties once set annual prices that the rest of the market adopted. The benchmark system has largely given way to index-linked pricing in iron ore, but the term persists and is sometimes loosely applied to any widely followed reference price, which can cause confusion with assessed or exchange-settled prices.
Markets
beneficiation
Beneficiation is everything done to raw dug-up rock to separate the useful mineral from the worthless rock around it, before the mineral is turned into a metal or chemical. Think of it as sorting and cleaning, not yet cooking.
技术层面: Beneficiation encompasses the physical and physico-chemical unit operations—crushing, grinding, screening, gravity separation, flotation, magnetic separation, and drying, among others—applied to run-of-mine ore to produce a concentrate or other upgraded product suitable for downstream processing. It excludes smelting, refining, and leaching steps that alter chemical composition through heat or reagent reaction, though the boundary is contested in some regulatory and trade contexts. The term is sometimes used interchangeably with 'mineral processing', but in policy and trade literature 'beneficiation' often carries the broader sense of any value-adding step applied to a raw mineral commodity within a producing country.
Mining
beneficiation requirement
A government rule that says a country must do some processing on its own raw materials before sending them out — so that more of the value-adding work stays at home.
技术层面: A policy instrument that obliges producers to carry out a defined level of mineral processing within the producing country before export is permitted. The threshold may be expressed in terms of minimum product grade, processing stage (concentrate, smelted metal, refined product) or value added. Beneficiation requirements are often confused with export controls, but the distinction matters: an export control restricts or bans the movement of a product, while a beneficiation requirement conditions export on the product first reaching a specified state of transformation.
Markets
blister copper
Copper that is nearly pure but still has small amounts of impurities trapped inside it. Its bumpy, blistered surface—caused by gas bubbles escaping as it solidifies—gives it its name.
技术层面: Blister copper is the product of converting copper matte in a Pierce-Smith or similar converter, in which iron sulfide is progressively oxidised and slagged off, leaving a crude copper metal typically containing small but commercially significant quantities of sulfur, oxygen, and trace impurity metals such as gold, silver, arsenic, and bismuth. The characteristic blistered surface forms because dissolved sulfur dioxide escapes during solidification. Although high in copper content, blister copper requires fire refining and then electrorefining before it meets the purity specifications of cathode copper traded on commodity markets.
Processing
block caving
A method where miners cut away the rock supporting a large mass of ore so that it slowly collapses under its own weight, breaking into pieces that can then be collected from tunnels below.
技术层面: A mass underground mining method in which a large column or block of ore is undercut, removing its support so that the overlying rock mass fractures and caves progressively downward under gravity. The broken material flows into draw points — funnel-shaped openings at the base of the cave — from which it is loaded and transported. Block caving is associated with very large, low-grade, roughly equidimensional orebodies, because its economics depend on extremely high throughput; the method is not selective and dilution from waste rock caving alongside ore must be managed carefully.
Mining
brine
Water with a very high concentration of dissolved salts — much saltier than seawater. Underground brines in certain deserts contain lithium, potassium, and other elements that can be extracted commercially.
技术层面: Brine is an aqueous solution with a total dissolved solids concentration substantially above that of seawater, typically formed by the dissolution of evaporite minerals or by long-term evaporative concentration of meteoric or volcanic waters in closed basins. In the context of mineral resources, the term refers specifically to subsurface or surface-ponded waters exploited for their content of lithium, potassium, boron, magnesium, or bromine. Brine differs from seawater not only in concentration but often in ionic ratios, which determine the processing route required; a high magnesium-to-lithium ratio, for instance, significantly complicates selective lithium recovery.
Geology
brownfield
A brownfield project is one carried out near or around an existing or former mine, where some rock has already been studied and some infrastructure already exists, giving explorers a head start.
技术层面: A brownfield exploration or development project operates in the proximity of an existing or previously mined deposit, benefiting from existing geological data, drill results, metallurgical knowledge, and often surface infrastructure such as roads, power, or processing facilities. Targeting in brownfield settings typically focuses on extensions of known mineralisation or satellite deposits within established geological corridors, which reduces some categories of exploration risk while introducing others, such as sterilised ground, legacy contamination, and tenure complications. Brownfield should not be confused with the environmental planning term of the same name, which refers to previously developed urban land; the mining usage is geological and logistical in scope.
Geology
by-product
Something useful that comes out of a factory or mine alongside the main product, but which was not the main reason for running the operation.
技术层面: A by-product is a saleable material recovered during the processing of a primary commodity, where the economics of the operation are driven by that primary commodity rather than by the by-product. The distinction matters in cost accounting: a by-product's revenue is typically credited against the cost of the primary product rather than allocated as a separate cost centre, and production volume is constrained by primary output rather than by its own demand.
Materials