Gangue in the context of "Non-ferrous extractive metallurgy"

A metallurgical furnace is an industrial furnace used to heat, melt, or otherwise process metals. Furnaces have been a central piece of equipment throughout the history of metallurgy; processing metals with heat is even its own engineering specialty known as pyrometallurgy.

One important furnace application, especially in iron and steel production, is smelting, where metal ores are reduced under high heat to separate the metal content from mineral gangue. The heat energy to fuel a furnace may be supplied directly by fuel combustion or by electricity. Different processes and the unique properties of specific metals and ores have led to many different furnace types.

The sulfate minerals are a class of minerals that include the sulfate ion (SO
₄) within their structure. The sulfate minerals occur commonly in primary evaporite depositional environments, as gangue minerals in hydrothermal veins and as secondary minerals in the oxidizing zone of sulfide mineral deposits. The chromate and manganate minerals have a similar structure and are often included with the sulfates in mineral classification systems.

In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. Waste valorization is the evaluation of waste and residues from an economic process in order to determine their value in reuse or recycling, as what was gangue at the time of separation may increase with time or more sophisticated recovery processes.

The extraction of minerals from ore can be done two ways: placer mining, which uses water and gravity to concentrate the valuable minerals, or hard rock mining, which pulverizes the rock containing the ore and then relies on chemical reactions to concentrate the sought-after material. In the latter, the extraction of minerals from ore requires comminution, i.e., grinding the ore into fine particles to facilitate extraction of the target element(s). Because of this comminution, tailings consist of a slurry of fine particles, ranging from the size of a grain of sand to a few micrometres. Mine tailings are usually produced from the mill in slurry form, which is a mixture of fine mineral particles and water.

Comminution is the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating, or other processes. Comminution is related to pulverization and grinding. All use mechanical devices, and many types of mills have been invented. Concomitant with size reduction, comminution increases the surface area of the solid.

For example, a pulverizer mill is used to pulverize coal for combustion in the steam-generating furnaces of coal power plants. A cement mill produces finely ground ingredients for portland cement. A hammer mill is used on farms for grinding grain and chaff for animal feed. A demolition pulverizer is an attachment for an excavator to break up large pieces of concrete. Comminution is important in mineral processing, where rocks are broken into small particles to help liberate the ore from gangue. Comminution or grinding is also important in ceramics, electronics, and battery research. Mechanical pulping is a traditional way for paper making from wood. The mastication of food involves comminution. From the perspective of chemical engineering, comminution is a unit operation.

Mineral processing is the process of separating commercially valuable minerals from their ores in the field of extractive metallurgy. Depending on the processes used in each instance, it is often referred to as ore dressing or ore milling.

Beneficiation is any process that improves (benefits) the economic value of the ore by removing the gangue minerals, which results in a higher grade product (ore concentrate) and a waste stream (tailings). There are many different types of beneficiation, with each step furthering the concentration of the original ore. Key is the concept of recovery, the mass (or equivalently molar) fraction of the valuable mineral (or metal) extracted from the ore and carried across to the concentrate.

11°01′00″S 76°26′00″W / 11.01667°S 76.43333°W / -11.01667; -76.43333

The Huarón Mining District is one of the richest polymetallic (Zn-Pb-Ag-Cu-(Au)) deposit clusters in Peru. It is located 20 km SSW of Cerro de Pasco, in the Huayllay District, Pasco Province, Pasco Department, between 4500 and 4700 m.a.s.l. The Huarón Mining District belongs to the Miocene polymetallic belt of the Central Andes. Hydrothermal mineralization occurs as predominantly in N-S to NNW-SSW and E-W veins as well as in "mantos" replacing favorable sedimentary rock. Epithermal hydrothermal fluids are thought to be derived from quartz-monzonitic intrusions tentatively dated at 7.4 Ma (K-Ar on adularia). The most important economic minerals are tennantite‐tetrahedrite (containing most of the silver), sphalerite, galena, and chalcopyrite. Silver is also found in pyrargyrite, proustite, polybasite, and pearceite. In the central copper core of the Huarón deposit, enargite occurs. Main gangue minerals are pyrite, quartz, rhodochrosite, and calcite.