APPENDIX I
Glossary of Mining Terms
Anticline: an upfold in rock strata, in this case on the seabed in Bass Strait, producing an arch or dome structure that provides a trap for hydrocarbons.
Barrel: 42 US gallons (159 litres).
Base metal: commercial metal such as copper, lead or zinc. The term was coined to indicate a metal ‘inferior’ to precious metals such as gold and silver.
Block-cave mining: an underground mining method in which is usually used to mine large ore bodies of a consistent grade, but it also allows for the bulk mining of large, relatively lower-grade ore bodies.
Bore-capping program: a method of saving water and restoring ore is allowed to collapse due to its own weight. Block caving artesian pressure through the capping and piping of old, uncontrolled bores. The Queensland Government’s bore-capping program in the Great Artesian Basin, for example, saves 130,000 megalitres of water each year.
Briquettes: small blocks formed by pressing material together.
Cap rock: an impervious rock acting as a seal so hydrocarbons such as oil and gas remain trapped in a reservoir.
Carbon-capture project: a worldwide effort to capture and remove carbon dioxide and other greenhouse gases, particularly from coal-burning power plants.
Carbon steel: steel that has properties made up mostly of the element carbon and that relies on the carbon content for structure. Most of the steel produced in the world is carbon steel.
Coke: a hard, dry carbon substance that provides the basic fuel consumed in blast furnaces in the smelting of iron. It is produced by heating coking coal to a very high temperature in the absence of air. Metallurgical coal burns fitfully, whereas coke provides steady heat.
Direct-reduced iron (DRI): processed iron ore that is iron-rich enough to be used as a scrap substitute in electric-furnace steelmaking.
Electric-arc furnace: a steelmaking furnace in which scrap is generally 100 per cent of the charge and heat comes from electricity that arcs from graphite electrodes to the metal bath.
Farm-in/farm-out: a partnership or joint venture in which the incoming partner – such as Esso in Bass Strait – funds the costs of exploration to earn a stake in a property owned by the farm-out partner, such as BHP Billiton.
Fines: the fine-grained ore produced by crushing and processing.
Flat products (steel): the steel market is primarily divided into two main categories – flat and long. A flat carbon-steel product is a plate product or a (hot or cold) rolled-strip product. Plate products vary in dimensions from 10 mm to 200 mm and thin flat-rolled products from 1 mm to 10 mm. Plate products are used for shipbuilding, construction, large-diameter welded pipes and boiler applications. Thin flat products find end-use applications in automotive body panels, domestic ‘white goods’ products, tin cans and a whole host of other products from office furniture to heart pacemakers. Plates, HR coils and HR sheet, CR sheet and CR coils, GP/GC (galvanised plates and coils), pipes, etc. are included in this category.
Flux: the material added to the contents of a smelting furnace or a cupola for the purposes of purging the metal of impurities and rendering the slag more liquid. The flux most commonly used in iron and steel furnaces is limestone, which is charged in the proper proportions with the iron and fuel. The slag is a liquid mixture of ash, flux and other impurities.
Hot-briquetted iron (HBI): a supplement for pig iron and scrap in electric-furnace steel mills. It is a compacted form of direct-reduced iron (DRI), which facilitates its handling, storage and use.
Leaching: a natural process in which ground waters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than contained originally.
Long products (steel): A long steel product is a rod or a bar. Typical rod products are the reinforcing rods made from sponge iron for concrete, ingots, billets, engineering products, gears, tools, etc. Wire-drawn products and seamless pipes are also part of the long-products group. Bars, rods, structures, railway materials, etc. are included in this category.
Longwall mining: an underground coal-mining method in which a steel plough or rotation drum is pulled mechanically back and forth across a coalface measuring several hundred metres long.
Mullock: mining refuse, muck.
Paydirt: rock that delivers a profit to the miner.
Pechiney AP30 technology: AP30 is the name of the design of the technology of the reduction line at the Hillside Smelter. The ‘30’ stands for 300,000 amps. An aluminium smelter is made of four main parts:
– Electricity rectification to generate the direct current (300 kA) and high voltage (1200 volts) required for the reduction line.
– The anode production plant to make the carbon source for the electrochemical reactions that occur in the reduction line.
– The reduction line, where alumina, carbon and electricity react together at over 950 degrees Celsius to produce molten aluminium. Each reduction line has approximately 264 reaction cells, each producing over 100 kg per hour.
– The aluminium cast-house, where liquid aluminium is moulded and cooled into shapes for sale.
The technology of the AP30 essentially finds the right balance between the following: heat, mass, chemistry, power and the magnetic field of the cell. This balance allows reliable long-life operations, which minimises power consumption, maximising production and aluminium purity.
Porphyry copper systems: large quantities of hydrothermal solutions carrying small quantities of copper pass through fractured, porphyritic rock and over time deposit the metal in huge ore bodies. The largest examples are found in the Andes in South America.
Raises (in mines): vertical openings driven upwards from one level to connect with the level above. In the block-caving method of mining, copper ore – ‘muck’ to the miners – flows down from the ore body into transfer raises and is carried away in ore trains or on conveyor belts.
Rod plant: see ‘long products’ above.
Spot market: commodities such as iron ore and oil are sold on the spot market for cash and delivered immediately.
Spot price: the price being paid on the spot market as opposed to the negotiated benchmark price.
Spud in: to drill a new well.
Stopes: the openings made in the process of extracting ore are called stopes or rooms. As mining progresses, the stopes are often backfilled with tailings. Shrinkage stope mining, or shrinkage stoping, is most suitable for steeply dipping ore.
SX/EW: solvent-extraction/electro-winning.
Tailings: waste product remaining from a mining operation after valuable minerals have been extracted, sometimes containing toxic chemicals.
Wildcat well: a well drilled ‘on spec’ in unproven territory.