How do we extract minerals?
The primary methods used to extract minerals from the ground are:
- Underground mining
- Surface (open pit) mining
- Placer mining
The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.
Higher-grade metallic ores found in veins deep under the Earth’s surface can be profitably mined using underground methods, which tend to be more expensive. Large tabular-shaped ore bodies or ore bodies lying more than 1,000 feet (300 m) below the surface are generally mined underground as well. The rock is drilled and blasted, then moved to the surface by truck, belt conveyor, or elevator. Once at the surface, the material is sent to a mill to separate the ore from the waste rock.
Lower grade metal ores found closer to the surface can be profitably mined using surface mining methods, which generally cost less than underground methods. Many industrial minerals are also mined this way, as these ores are usually low in value and were deposited at or near the Earth’s surface. In a surface mine, hard rock must be drilled and blasted, although some minerals are soft enough to mine without blasting.
Placer mining is used to recover valuable minerals from sediments in present-day river channels, beach sands, or ancient stream deposits. More than half of the world’s titanium comes from placer mining of beach dunes and sands. In placer operations, the mined material is washed and sluiced to concentrate the heavier minerals.
Does the USGS have reports on the background levels of elements in soils and other surficial materials?
U.S. mines produced an estimated $75.2 billion of raw mineral materials in 2017 – a 6 percent increase over 2016 – the U.S. Geological Survey announced Wednesday, January 31, in its annual Mineral Commodity Summaries.
It would be no exaggeration to say that without minerals, no aspect of our daily lives would be possible.
No, it’s not a title for a new reality-dating TV show, but it is real science! It also describes the ideal mineral deposit.
In 2016, these five states led the pack in mineral production, accounting for about one third of the total mineral production value for the entire country.
In 2016, the United States mined $74.6 billion worth of minerals, and the following five mineral commodities accounted for 68.5 percent of that value.
- The U.S. is increasingly reliant on supply of mineral raw materials from other countries.
- Advanced technologies are increasingly making use of nearly the entire periodic table of the elements.
- Dynamic studies of critical and strategic mineral supply and demand can identify emerging potential supply risks.
- The USGS - National Minerals
Mineral Origin: Les Baux, France (Sample donated by Gary Kingston)
Primary Commodity: Aluminum and Gallium
Primary Commodity Uses: Aluminum is one of the most used metals on the planet, finding roles in transportation, construction, packaging, electronics, and other consumer
Mineral: Chalcopyrite, Pentlandite, Pyrrhotite
Mineral Origin: Creighton Mine, Sudbury, Ontario, Canada (Sample on loan from George J. Coakley)
Primary Commodity: Copper and nickel
Primary Commodity Uses: Copper is used primarily in electronics, mostly in building construction and industrial
Sphalerite, zinc sulfide, is and has been the principal ore mineral in the world. Zinc uses range from metal products to rubber and medicines. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal’s resistance to corrosion is an...
Copper mines can be loud and sometimes chaotic places, but they provide Zambia with plenty of revenue and jobs. Photograph credit: Mark Cocker, USGS
Sample of eudialyte (pink) within layered vein consisting of quartz, albite, and sodic amphibole, Dora Bay, Alaska. Size of sample is 11 by 9 cm. Sample of coarse-grained, tabular bastnäsite within matrix of ferruginous dolomite, Birthday Claim, Mountain Pass, California. Photographs by Philip Verplanck, U.S. Geological Survey. SIR 2010-5070-J
by Andrea Foster, USGS Research Geologist & Christopher Kim, Associate Professor, Chapman University
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Blocks of biotitic meta-sandstone from the lower part of the Gunsight Formation, and drill core from the underlying banded siltite unit of the Apple Creek Formation, lying on the dump of the lower workings of the Copper Queen mine, southeast of the Blackbird cobalt-copper mine area.
Sampling acid mine drainage residuals in Elk County, Pennsylvania. The USGS has pioneered a new use for these residuals that are currently a disposal challenge, using them to filter phosphorus from agricultural and municipal wastewaters.
An abandoned mine shaft taken in the Mojave Basin and Range Ecoregion (NV) in August 2002.