Table of Contents
Gold mining involves the extraction of gold from various sources, initially focusing on alluvial deposits using manual methods like gold panning. Over time, the industry has evolved, incorporating complex processes such as pit mining and gold cyanidation for ores not on the surface. Large corporations dominated gold mining in the 20th and 21st centuries, but the high value of gold led to the involvement of millions of small, artisanal miners in the Global South.
The history of gold mining dates back thousands of years, with evidence suggesting early mining activities in locations like Varna Necropolis in Bulgaria around 6,724 years ago. Nubians, Egyptians, and Romans engaged in gold mining during various historical periods, utilizing different techniques such as grinding mills and hydraulic mining methods. The Roman conquest of Britain and campaigns in other regions were motivated, in part, by the pursuit of gold resources.
During the 19th century, gold rushes, such as the California Gold Rush and the Witwatersrand discovery in South Africa, triggered large-scale migrations of miners. In more recent times, discoveries like the Carlin Trend in Nevada in 1961 have contributed to the ongoing global gold production. However, the gold mining industry is not without challenges, as issues related to human rights, environmental concerns, and health and safety risks are common, particularly in regions with less regulatory oversight.
Statistics Production
In 2022, global gold production reached 3,612 tonnes. China emerged as the leading gold producer with 368.3 tonnes, followed by Russia with 331.1 tonnes and Australia with 327.8 tonnes in the same year. Despite a decrease in gold content in ores, overall production has been on the rise, attributed to the implementation of larger-scale industrial installations and advancements, particularly in hydrometallurgy.
Gold Production Methods.
Gold mining encompasses various methods, including hard rock mining, by-product gold mining, and niche, recreational, or historical methods. Hard rock mining involves extracting gold encased in rock, often using open-pit or underground mining. By-product gold mining occurs in large copper mines or sand and gravel pits. Recreational gold mining methods, such as gold panning, have become popular outdoor activities in several countries, including the United States, Canada, Australia, and New Zealand. Gold panning is a form of placer mining that extracts gold from a placer deposit using a pan, making it popular due to its low cost and relative simplicity. However, its productivity rate is comparatively smaller compared to other methods. The process involves agitating the material in the pan in water to separate the heavier gold from the lighter materials. While panning usually turns up only minor gold dust, it can be used to locate the parent gold veins, which are the source of most placer deposits.
Gold mining methods include hard rock mining, where gold is extracted from rock formations, either through open-pit mining or underground tunnels. Notably, South Africa hosts the world’s deepest hard rock gold mine at 3,900 meters underground, requiring air conditioning for worker safety.
By-product gold mining occurs in conjunction with other primary products, such as copper. Large copper mines may recover significant amounts of gold, like the Grasberg mine in Indonesia, primarily a copper mine but also a major gold producer.
Recreational gold mining and prospecting, popular in various countries, involve small-scale placer mining. However, it faces environmental challenges, potentially reintroducing pollution from old placer deposits.
Gold panning, a traditional gold mining method, uses a pan to extract gold from placer deposits. Although simple and cost-effective, its productivity is lower compared to commercial methods, leading to its replacement in the mainstream market.
Placer mining is a technique for extracting gold from loose materials in placer deposits, where traditional tunnelling is challenging. Water or dredging methods are commonly employed in this process.
Sluicing:
- Sluice boxes are man-made channels with riffles at the bottom, creating dead zones for gold to settle out of suspension.
- Placed in streams, water flow channels through the box, allowing gold-bearing material to settle behind the riffles.
- Larger operations use screening plants or trommels to remove larger materials before concentrating in a sluice box or jig plant.
- Commercial placer mining involves diesel-powered equipment like excavators, bulldozers, wheel loaders, and rock trucks.
Dredging:
- Small-scale miners use suction dredges floating on water, controlled by one or two individuals.
- Consists of a sluice box on pontoons, attached to a suction hose, operated by a miner underwater.
- Some states have specific regulations for dredging, specifying seasonal periods and area closures to protect fish populations.
- Larger suction dredges are used in commercial production globally, improving gold extraction efficiency.
Other large-scale dredging operations:
- Take place on exposed river gravel bars during seasonal low water.
- Employ land-based excavators feeding gravel screening plants and sluice boxes floating in temporary ponds.
- Gold trapped in the onboard sluice box, with tailings stacked behind, steadily filling the pond as operations progress.
- Characterized by low cost, minimal environmental impact, and recycling process water.
Rocker Box: During the California Gold Rush, miners utilized the Gold Rocker Cradle to extract gold nuggets and dust from gravel with minimal water usage. Its portability was a key advantage, allowing miners to easily move to new diggings. The size of the model is illustrated by the quarter. A genuine Gold Rocker Cradle is on display at the James Marshall Gold Discovery Park in Coloma, California, offering a firsthand look at the equipment used during that historic period.
- Also known as a cradle, it uses riffles in a high-walled box to trap gold, similar to a sluice box but with less water.
- Suited for areas with limited water, as a rocking motion provides the necessary water movement for gravity separation of gold in placer material.
Gold ore processing
Gold ore processing involves various methods, with the dominant one being cyanide extraction introduced in the late 1800s. This process uses sodium cyanide to treat finely ground rock, absorbing the extract onto carbon. The carbon is then treated with caustic soda and cyanide to convert gold cyanide into relatively pure gold through a process called gold parting. However, this method poses environmental hazards due to the high toxicity of cyanide compounds.
Another historical method involves the use of mercury in placer gold mining, forming mercury-gold amalgam to increase gold recovery rates. Boiling away the mercury from the amalgam concentrates the gold. While effective for extracting small gold particles, the process is hazardous due to mercury vapour toxicity. Large-scale mercury use in gold mining ceased in the 1960s, but it persists in artisanal and small-scale gold mining (ASGM).
Gold mining encompasses various scales, from small artisanal miners to large multinational corporations. Around 80% of global gold supply is produced by major corporations like Newmont and Barrick Gold. However, an estimated 10 to 15 million small-scale artisanal gold miners exist globally, with environmental hazards, unsafe working conditions, and child labor prevalent in this sector.
Gold mining activities can significantly impact the environment, causing deforestation, pollution of air and water with cyanide or mercury, and the production of hazardous waste. Large mining companies may contribute to environmental degradation, and local communities often lack protection or regulation. Responses to these issues include initiatives like Fairtrade and Fairmined certification, the “No Dirty Gold” campaign advocating for responsible mining techniques, and calls for changes in the industry to ensure human rights and environmental protection.
Peak gold.
Peak gold refers to the point when the maximum rate of global gold extraction is reached, following the Hubbert peak theory. Gold, unlike petroleum, can be reused and recycled. World gold demand in 2007 was 3,519 tonnes, categorized into central bank reserves, jewelry production, industrial consumption, and investment. Gold supply comes from mining, official sales, de-hedging, and old gold scraps, with the total world supply in 2007 being 3,497 tonnes.
World mined gold production has peaked four times since 1900, with the latest peak in 2001 at 2,600 metric tons. Production declined for several years but increased again from 2009, reaching record highs each year from 2011 through 2015. Estimates for 2016 indicate production was flat compared to 2015, at 3,100 tonnes. Predictions on the timing of peak production vary , with some suggesting it occurred in 2000, while others project a peak between 2022 and 2025 due to lower grades and remote locations of known undeveloped deposits.
Peak Gold Summary:
Peak gold refers to the point in time when the maximum rate of global gold extraction is reached, followed by a decline in production. Unlike petroleum, gold is a reusable resource.
Supply and Demand:
- World gold demand in 2023 was 4,899t, encompassing central bank reserves, jewelry production, industrial consumption, and investment.
- Gold supply comes from mining, official sales, de-hedging, and old gold scraps, with the total world supply in 2007 at 3,497 tonnes.
- Yearly gold mining produces 2% of existing above-ground gold (158,000 tonnes as of 2006), and in 2008, gold mining produced 2,400 tonnes.
Timing of Peak Production:
- World mined gold production peaked in 1912, 1940, 1971, and 2001, with each peak surpassing previous ones.
- The most recent peak was in 2001 at 2,600 metric tons, followed by a decline and subsequent increase spurred by high gold prices.
- Estimates for 2016 production indicate it was flat compared to 2015, standing at 3,100 tonnes.
Expert Opinions on Peak Gold:
- Barrick CEO Aaron Regent suggested global production peaked in 2000, but production costs trended down.
- Natural Resource Holdings CEO Roy Sebag predicted peak gold between 2022 and 2025, citing lower grades and remote locations of known deposits.
- Goldcorp CEO Charles Jeannes in 2014 predicted Peak Gold in 2014 or 2015, emphasizing the scarcity of new mines.
Economics of Gold:
- The gold price, compared to other valuable metals, holds its value consistently and is less prone to price changes.
- Gold production tends to excel during turbulent market conditions, providing an alternative investment opportunity.
- Factors affecting gold prices include central bank gold reserves, the value of the U.S. dollar, and its inverse relationship with gold.
Gold mining by country.
- Gold Mining in Mexico.
- Gold mining in the United States – USA.
- Gold mining in China.
- Gold mining in South Africa.