How gold is mined
Global gold production is over 3,000 tons per year. Russia ranks third
Gold is mainly obtained through miningmines and deposits. Primary deposits are called primary accumulations of mineral matter in the subsoil that have not been transformed. Also, placer deposits, which are formed as a result of the destruction of primary ones, still play a major role in Russia. Placer gold production exceeds 50-70 tons per year; in this indicator, the country has held first place in the world for many years.
Gold ore goes through several complex stages,before it becomes ingots: it is crushed, sorted, the metal itself is separated using various technologies, and sent for refining to clean it of impurities.
Impact on the environment
Environmentalists have long been sounding the alarm about the impactthe environmental impact of gold mining. Placer gold is found in river beds. The soil is raised from the river bottom using special machines. To find gold particles, it is washed with water, which fills with sand and clay and becomes cloudy. Often, the water is dumped back into the rivers without being cleaned first. As a result, after several iterations, the free flow of the river turns into a chain of stagnant, dirty ponds.
In 2020, environmentalists in Russia discoveredpollution of rivers downstream of gold mining sites with a length of about 2,650 km. At the same time, over the past 20 years, the volume of issuing licenses for alluvial gold has begun to increase in Russia: in the Amur Region alone, about 1,000 such licenses were issued in 2021.
There are also problems with extraction from indigenousdeposits. Thus, cyanide and mercury are still often used to extract gold from ore. This process is controversial due to the high toxicity of the chemicals. Mercury, which causes damage to the nervous system even at relatively low levels of exposure, can pollute the atmosphere and water at a very long distance. And cyanide, which does not allow the cells of the body to use oxygen, enters the water, soil or air.
The environmental impact of gold mining can be reduced, in particular, through more active recycling of gold.
Where is gold used and where does it come from for processing?
Gold is ductile, malleable and resistant tocorrosion resistant metal and an excellent conductor of heat and electric current. Today it is used in the automotive industry, electronics, telecommunications, energy, chemistry, medicine, nanotechnology, aviation and spacecraft. Gold helps catalyze unburned fuel in automotive systems, increases the efficiency of collecting solar energy, and is found in medical implants.
Gold can be found in microchips, capacitors,transistors, resistors and connectors. For example, contacts on SIM cards are coated with it (although the thickness of such a layer is up to 100 nm). Modern electronics use much less precious metals, but they are still found in phones, iPads, computers and other equipment. The system unit of a computer manufactured before 2010 can contain up to 1 g of gold, and new Intel processors - from 0.1 g. In 2011, according to the US Geological Survey, on average 0.034 grams of gold could be found in each mobile phone.
Weibo user from China nicknamed ChefAlchemist recently bought 210 smartphone circuit boards and was able to extract just 0.41 grams of gold from them after long chemical reactions. Its cost was only $30. He spent $315 on the purchase. From this we can conclude that under artisanal conditions, the extraction of this metal from microcircuits is completely unprofitable.
But if we are talking about a well-establishede-waste processing enterprise, the activity can be profitable: out of 1 million cards from mobile phones, you can get about 34 kg of gold (in addition to other precious metals). This is especially true given the fact that the amount of electronics at CIS landfills has grown by 1.5 times over 10 years, and only 3.2% is recycled.
Methods and technologies of gold processing
Classical approaches
When recycling coins and jewelry, the first step issorting of gold depending on its purity (in our country it is determined by the sample, that is, the content of grams of gold per kilogram of jewelry alloy). Using special devices, specialists determine the amount of impurities. After sorting, the gold is melted and either poured into ingots or melted to remove impurities (they are burned in the process). Another option is to add flux as an insulator and cleaning component to separate the pure metal.
Recycling of gold from industrial and electronicwaste is more difficult because the precious metal is embedded in plastic or metal. So first the gold parts are extracted, then recycled. The first method is chemical cleaning with a compound that reacts with the gold. The second is melting the metal components, cooling them and grinding them. In any case, both methods require cleaning the gold from impurities.
New ways
Recently, researchers from ManchesterUniversity, Tsinghua University and the Chinese Academy of Sciences have proposed a simpler method to extract gold from discarded electronics. All you need is some graphene (a form of carbon). The electronics are dissolved in acid, a sheet of graphene oxide is dipped into the solution, and the gold is deposited on it. Then, it is enough to burn the graphene to get the desired metal.
Just one gram of graphene is enough toextracting almost twice as much gold. The method makes it possible to obtain 95% of valuable metal from electronics even at the minimum concentration. Importantly, graphene does not attract other metals in the e-waste mix.
Another interesting example:technology from New Zealand-based Mint Innovation. Using naturally occurring microbes and chemicals, the company extracts precious metals from shredded and powdered e-waste. Mint plans to build a biorefinery in every major city in the world. In late 2020, the startup raised NZ$20 million ($14 million) to build its first two plants in Sydney, Australia, and northwest England.
The company claims that its approach emits 90% less carbon and uses only 2% electricity and water per kilogram of gold compared to conventional mining.
What is made from recycled gold
Most often - jewelry.For example, in 2018, Dell and actress Nikki Reed introduced The Circular Collection from the brand Bayou with Love. Jewelry was made from gold extracted from computer motherboards. According to research from Trucost, the reclamation process, developed by Dell partner Wistron GreenTech, has a 99% lower environmental impact than traditional mining.
And Pandora announced back in 2020 that it wouldBy 2025, Pandora will eliminate all new silver and gold from its designs and buy them from recyclers. This will help the company reduce CO2 emissions by more than 99% for gold. At the time of the announcement, Pandora jewelry contained 71% recycled precious metals.
Prada recently launched a jewelry collectionproducts made from 100% recycled gold. It is obtained from electronic components and old jewelry. The company also uses diamonds mined and processed in accordance with ecological and humanitarian principles. Each Prada piece is packaged with a warranty card sewn into the chip, certifying the origin of the material, using the Aura Consortium blockchain. The collection includes necklaces, earrings, bracelets and rings.
Other brands also use recycled gold: Annoushka, Anonymous, Courbet, Loyal.e Paris, and so on.
In Russia, a similar project was implemented in 2021"Bronnitsky Jeweler": the company collected old jewelry in its stores and then released an ECO collection made from recycled precious metal. We at Moneygold also accept gold for recycling, including courier delivery, and hand it over to a refinery.
Such plants typically produce highly pureprecious metals for the financial sector, bullion production, and jewelry industry. For example, the Krasnoyarsk refinery "Krasnoyarsk Non-Ferrous Metals Plant" produces refined gold, silver, and other precious metals in bullions, granules, and powder. And the Moscow Plant for Processing Special Alloys also makes gold wires and foil, and jewelry blanks.
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Although gold mining technologies are improving,the industry still causes significant damage to the environment. Recycling gold, including from electronic components, can reduce this harm and give the precious metal a second life. To make this possible, it is important not only to introduce innovative recycling solutions, but also to raise consumer awareness.
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