The Chilean mill was a machine used on gold fields in an early period of gold mining. The machine was composed of two rotating wheels that would revolve over a pan filled with gold-bearing rocks. The idea was that the wheels would break open the rocks with gold, so they could harvest gold from multiple rocks at a time.
One of the earliest such machines was built in Ballarat in Victoria, Australia during the Victorian gold rush and was combined with a sluice for extracting the gold. [1] Another such machine in Australia was used, at the Fitzroy Iron Works, to grind clay for making firebricks. The bricks were needed for repairing the many furnaces at the works. [2]
The Chilean mill, known in Chile as a "trapiche," is still in use in artisanal gold mining in the Andes Mountains. In the process, the crushed rock passes over metal plates coated with mercury where the gold inclusions adhere to the mercury. [3] The gold is recovered after the evaporation of the mercury over a fire. The mill sometimes has two wheels driven by a belt attached to a motor, or a single wheel driven by mules, oxen, or other pack animals. Working Chilean Mills can still be seen in Andacollo Chile. [4]
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. Exploitation of these deposits for raw material is based on the economic viability of investing in the equipment, labor, and energy required to extract, refine and transport the materials found at the mine to manufacturers who can use the material.
The California Gold Rush (1848–1855) was a gold rush that began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California from the rest of the United States and abroad. The sudden influx of gold into the money supply reinvigorated the American economy, and the sudden population increase allowed California to go rapidly to statehood, in the Compromise of 1850. The Gold Rush had severe effects on Native Californians and accelerated the Native American population's decline from disease, starvation and the California genocide.
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel, with a number of blades or buckets arranged on the outside rim forming the driving car. Water wheels were still in commercial use well into the 20th century but they are no longer in common use. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth.
A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand or by animals, working animal, wind (windmill) or water (watermill). In modern era, they are usually powered by electricity.
Gold mining is the extraction of gold resources by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. However, with the expansion of gold mining to ores that are not on the surface, has led to more complex extraction processes such as pit mining and gold cyanidation. In the 20th and 21st centuries, most volume of mining was done by large corporations, however the value of gold has led to millions of small, artisanal miners in many parts of the Global South.
The Dolaucothi Gold Mines, also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the Dolaucothi Estate which is now owned by the National Trust.
The ancient Romans were famous for their advanced engineering accomplishments. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources.
A stamp mill is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation.
Andacollo is a city and commune in the Elqui Province, Coquimbo Region, Chile.
Arrium was an Australian mining and materials company, employing nearly 10,000 workers, that went into voluntary administration in 2016 with debts of more than $2 billion. In 2017 it was acquired by British-owned Liberty House Group.
Silver mining is the extraction of the precious metal silver from the Earth through excavation.
The Black Hills Gold Rush took place in Dakota Territory in the United States. It began in 1874 following the Custer Expedition and reached a peak in 1876–77.
Gold became highly concentrated in California, United States as the result of global forces operating over hundreds of millions of years. Volcanoes, tectonic plates and erosion all combined to concentrate billions of dollars' worth of gold in the mountains of California. During the California Gold Rush, gold-seekers known as "Forty-Niners" retrieved this gold, at first using simple techniques, and then developing more sophisticated techniques, which spread around the world.
The Washington Winch sits in the forests of eastern Victoria near Swifts Creek and is also known as the Washington Iron Works Skidder.
Quartz reef mining is a type of gold mining in "reefs" (veins) of quartz. Quartz is one of the most common minerals in the earth's crust, and most quartz veins do not carry gold, but those that have gold are avidly hunted by prospectors. In the shallow, oxidized zones of quartz reef deposits, the gold occurs in its metallic state, and is easily recovered with simple equipment. Quartz reef mining played an important role in 19th century gold-mining districts such as Bendigo, Victoria, Central Otago in New Zealand, and the California mother lode.
The Powelltown Tramway was a 3 ft narrow gauge tramway that operated between Powelltown and Yarra Junction, Victoria, Australia. It operated between 1913 and 1945.
Andacollo is a second category municipality and the administration seat of Minas Department in the province of Neuquén, Argentina. Located in a valley surrounded by the Wind Mountain Range, it is the second-largest municipality in the north of the province after Chos Malal.
Metals and metal working had been known to the people of modern Italy since the Bronze Age. By 53 BC, Rome had expanded to control an immense expanse of the Mediterranean. This included Italy and its islands, Spain, Macedonia, Africa, Asia Minor, Syria and Greece; by the end of the Emperor Trajan's reign, the Roman Empire had grown further to encompass parts of Britain, Egypt, all of modern Germany west of the Rhine, Dacia, Noricum, Judea, Armenia, Illyria, and Thrace. As the empire grew, so did its need for metals.
During the Australian gold rushes, starting in 1851, significant numbers of workers moved from elsewhere in Australia and overseas to where gold had been discovered. Gold had been found several times before, but the colonial government of New South Wales had suppressed the news out of the fear that it would reduce the workforce and so destabilise the economy.
The Tamar Hematite Iron Company (THIC) was an iron mining and smelting company that operated from April 1874 to December 1877, in the area close to the location of the modern-day township of Beaconsfield, Tasmania, Australia.