Mineral processing, otherwise known as mineral dressing, is the practice of beneficiating valuable minerals from their ores. Industrial mineral treatment processes usually combine a number of unit operations in order to liberate and separate minerals by exploiting the differences in physical properties of the different minerals that make up an ore. Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ...

Many plants also incorporate hydrometallurgical or pyrometallurgical processes as part of an extractive metallurgical operation. Hydrometallurgy is the field of extractive metallurgy involving the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials. ...

Mineral processing involves four general types of operations: comminution or particle size reduction, sizing or separation of particle sizes by screening or classification, concentration by taking advantage of physical and surface chemical properties, and dewatering or solid/liquid separation.

A number of auxiliary materials handling operations are also considered a branch of mineral processing such as storage (as in bin design), conveying, sampling, weighing, slurry transport, and pneumatic transport. Articles on Material handling equipment include: Bulk material handling Forklift truck Category: ...

Comminution

Comminution is particle size reduction of materials. Comminution may be carried out on either dry materials or slurries. Crushing and grinding are the two primary comminution processes. Crushing is normally carried out on "run-of-mine" ore, while grinding (normally carried out after crushing) may be conducted on dry or slurried material. Look up comminution in Wiktionary, the free dictionary. ... Death by crushing or pressing is a method of execution which has a long history during which the techniques used varied greatly from place to place. ... The word grinding can mean many things: Grinding is a manufacturing process that uses friction with a rough surface to wear away or smooth the surface of a work piece - see grinding machine. ...

Sizing

Sizing is the general term for separation of particles according to size.

The simplest of sizing processes is screening, or passing the particles to be sized through a screen or number of screens. Screening equipment can include grizzlies, bar screens, and wire mesh screens. Screens can be static (typically the case for very coarse material), or they can incorporate mechanisms to shake or vibrate the screen.

Classification refers to sizing operations that exploits the differences in settling velocities exhibited by particles of different size. Classification equipment may include ore sorters, gas cyclones, hydrocyclones, rake classifiers, rotating trommels, or fluidized classifers. When the feed material contains particles of different densities as well as particles of different size, a degree of concentration takes place during classification because settling velocities are also dependent on particle density.

Froth flotation

Froth flotation is achieved when particles are separated based on their surface potential. Hydrophobic particles are recovered to the froth, whereas hydrophilic particles are discharged with the tailings stream. Some mineral particles are naturally hydrophobic, whereas others require specific reagent additions to change their surface potentials. Oxide ores, such as spodumene and tantalite can be treated using oxalic acid based collectors. Sulfide ores can be recovered using xanthate or dithiophosphate type collectors. Froth Flotation is a selective process for separating minerals from gangue by using surfactants and wetting agents. ... An oxide is a chemical compound containing an oxygen atom and other elements. ... Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate - LiAl(SiO3)2 - and is a source of lithium. ... Tantalite, [(Fe, Mn) Ta2O6], is a mineral that is close to columbite. ... Oxalic acid (IUPAC name: ethanedioic acid, formula C2H2O4) is a dicarboxylic acid with structure (HOOC)-(COOH). ... Formally, sulfide is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water. ...

Gravity concentration

Particles can be classified based on their specific gravity. Gravity concentration processes include: Relative density (also known as specific gravity) is a measure of the density of a material. ...

• Heavy media or dense media separation
• Shaking tables, such as the wilfely table
• Spirals
• Centrifugal bowl concentrators
• Jig concentrators are continuous processing gravity concentration devices.
• Multi gravity separators
• Knelson concentrators Company Website

Electrostatic separation

Non-conducting particles maintain an electrostatic charge induced electrically, and so remain pinned to a charged drum. Conducting particles do not maintain the electrostatic charge and so fall off the drum, thus minerals such as ilmenite and rutile can be separated. Ilmenite is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and igneous rocks. ... Rutile in trellis texture characteristic of secondary rutile. ...

Magnetic separation

Minerals such as magnetite and pyrrhotite are naturally magnetic, and so can be separated from non-magnetic particles using strong magnets. // Headline text Magnetite is a ferrimagnetic mineral form of iron(II,III) oxide, with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. ... Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: Fe(1-x)S (x = 0 to 0. ... In physics, magnetism is a phenomenon by which materials exert an attractive or repulsive force on other materials. ...

External links

• Minerals Engineering International