In mining, the term backfilling refers to the filling-in of the cavity between the excavated area and the rock mass using suitable materials. Various materials (such as gravel) and a number of different technologies are used for backfilling.
Grinding of ore
A ball mill is a mill for ultrafine grinding or homogenization. It consists of a rotating grinding jar (steel cylinder) into which the material to be ground (ore) is fed. Grinding balls made of various materials are added – in the case of ore, the balls are made of steel. Rotation of the ball mill pulverizes the ore.
Banded iron formation
Banded iron formations are units of iron-bearing marine sedimentary rock that were primarily deposited in the Precambrian period. They possess a characteristic banded structure due to their metal-bearing layers. The layers primarily consist of ferrous minerals with a vertical cross-section reminiscent of bands. This is what gives them their name.
Basalt is a basic igneous rock. It consists in particular of iron and magnesium silicates with pyroxenes and calcium-rich feldspar (plagioclase) and also usually also olivine. Basalt is the volcanic equivalent of gabbro (plutonite), which has the same chemical composition. Basalt is usually dark gray to black. Because the rock is formed through the action of volcanic processes, the groundmass is usually fine-grained due to the rapid cooling it undergoes.
Base metals are characterized by the fact that they oxidize – under normal conditions they react with oxygen in the air. For example, iron rusts. Zink and aluminum protect themselves through passivation, which is the formation of a corrosion-resistant oxide layer that prevents further oxidation. Base metals differ chemically from noble metals in that their redox pairs have a negative instead of a positive standard electrode potential (relative to the standard hydrogen electrode).
Bauxite is an aluminum ore that consists primarily of the aluminum materials gibbsite (hydrargillite) and diaspore as well as the iron oxides haematite and goethite, the clay material kaolinite and small amounts of the titanium oxide anatase. Bauxite takes its name from its place of discovery, Les Baux-de-Provence in the south of France. It was unearthed there for the first time in 1821.
A system for moving bulk material
Machine which transports bulk material on a conveyor belt. It mainly consists of a supporting structure made of steel sections, a drive station, a return station, idlers and a conveyor belt.
Mining of ore
Block caving is an underground mining method in hard rock in which an ore body is undercut until it finally collapses under its own weight. This can cause the formation of large surface depressions called dolines or sinkholes. The method is an economical means of mining large ore deposits.
Vertical transport of powdery or small-sized bulk material
A continuous conveyor for vertically elevating powdery or small-sized bulk material. The buckets are attached to a double- or single-strand chain, a pintle chain or a belt. Vertical continuous conveyor with buckets used as support elements that scoop the material to be transported or are filled and emptied in certain areas. Belts or chains are used as traction elements.
Efficient and safe handling of bulk material
Systems for moving, processing and packaging different kinds of bulk material. These can be belt conveyors, palletizers, packaging machines or loading equipment. The aim is to transport the material safely from the excavation point to the destination.
A granular or fragmented mixture in pourable form
Bulk materials are different kinds of lumpy, granular and powdered products like e.g. ores, coal, peat, sand, saw dust, cement. Accord. to VDI 2411 bulk materials are “loose, pourable materials to be conveyed”.
Transshipment port for bulk goods
The area of a port used for transshipment of bulk goods. The warehouse capacities, loading equipment and packaging facilities are designed for handling bulk goods.