Tailings in the context of "Placer mining"

A gold nugget is a naturally occurring piece of native gold. Watercourses often concentrate nuggets and finer gold in placers. Nuggets are recovered by placer mining, but they are also found in residual deposits where the gold-bearing veins or lodes are weathered. Nuggets are also found in the tailings piles of previous mining operations, especially those left by gold mining dredges.

In mining, overburden (also called waste or spoil) is the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above a coal seam or ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally finely milled ore. Overburden is removed during surface mining, but is typically not contaminated with toxic components. Overburden may also be used to restore an exhausted mining site during reclamation.

Interburden is material that lies between two areas of economic interest, such as the material separating coal seams within strata.

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.

A stacker is a large machine used in bulk material handling. Its function is to pile bulk material such as limestone, ores, coal and cereals onto a stockpile. A reclaimer can be used to recover the material.

Gold dredges in Alaska had a stacker that was a fixed part of the dredge. It carried over-size material to the tailings pile.