How gold is mined
Editorial
Promdevelop editorial team
Gold was one of the first metals that man began to use, and jewelry was made from it even at a time when the main materials were stone and wood.
- Where is gold found in nature?
All this is due to one property - the element is often found in nature in almost pure form, in nuggets.
For a long time, gold remained only a means of payment and a material for jewelry. Over time, the metal has become indispensable in medicine, electrical engineering, weapons production and other sectors of the economy of all countries of the world. Despite the replacement of monetary standards, any country tries to ensure a certain gold reserve.
However, where did this chemical element come from (in D.I. Mendeleev’s table of chemical elements, gold is designated as Au (aurum) at number 79), how is it mined and used?
A little history
Because gold could be found almost anywhere in the world, it became an essential element in almost all human cultures.
Starting with Ancient Egypt, where decorative gold objects dating back over 5,000 years have been found. Advertising - Continued below
The beauty of gold was associated by ancient people with immortality and the wealth of the gods, so jewelry and decorative elements were made from it. Gold was also one of the first currencies to replace traditional barter exchange.
Children's gold bracelet. Egypt. Approximately 2650 BC Photo: www.metmuseum.org
The very first gold coins were minted in the kingdom of Lydia in 550 BC, and since then this metal has remained the main element of the monetary system. Even after modern paper money was adopted, currencies remained linked through the Gold Standard, a system introduced in the 1870s that fixed the value of these currencies in a certain amount of gold.
Physical and chemical properties of metal
This is one of the few noble metals that can be found in nature in its pure form. Pure gold is very soft, only 2.5-3 on the Mohs hardness scale. This is a plus for easy metal processing: one gram of gold can be rolled into a thin sheet with a thickness of only 230 atoms and an area of one meter. But the softness of gold is a disadvantage for the strength of products made from it, so gold is most often alloyed with other metals.
Gold is a good conductor of heat and electricity and is resistant to oxidation and corrosion. The noble metal has a very high boiling and melting point.
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The temperature required to melt gold is 1065°C and the boiling point is 2856°C.
How gold is mined
North-Eastern Siberia, Kuranakh ore field.
Photo: PJSC Polyus Gold mining is carried out in the following countries: South Africa, Australia, USA, Canada, Russia, China and Pakistan. One of the largest gold mines is the Aurora mine, located in Guyana, Africa.
In ancient times, pieces of gold were simply found in a river or earth. During the Gold Rush, gold was mined by hand using a pick and shovel. By 1853, hydraulic mining had emerged and replaced independent gold miners. Today, gold is mined in large open-pit or underground mines.
The process begins with geologists taking samples of the ore to determine the best places to mine. Once mining engineers know where the gold is and what other materials surround it, the mining process can begin.
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If gold is located close to the surface, it is mined by open-pit mining. In fact, a huge hole is dug in the ground, along the inner perimeter of which a road goes down like a spiral. Equipment for mining and moving ore goes down and up along this road.
Production processes in the production of precious metals
The heap gold leaching method involves a number of production processes, the result of which is the yield of a pure precious product:
- after delivering the gold ore to the processing plant, it is placed in mills, where it is crushed to a certain fraction;
- after this, the material is passed through sieves and goes through a pelletizing stage, which prevents the factions from sticking together into large compounds;
- then the resulting mass is sent for leaching with sodium cyanide and formed into an ore pile;
- the next step is the separation of waste ore from metal cyanide compounds by sorption;
- the extracted gold-containing compounds are sent for galvanization, where preliminary purification occurs.
The completion of the process is the melting of the resulting sediment until the alloy is released, which is subsequently leached from ore residues.
Modern uses of gold
Gold can be called the most popular precious metal of any era. Now it is used in various fields of human activity: from creating simple jewelry to complex medical devices.
Jewelry
Gold has been used to make jewelry for thousands of years. Today, up to 80% of mined or processed gold is used in jewelry. One of the reasons why this precious metal is so popular among jewelers is its malleability - gold can be used to create the most delicate works.
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Of course, jewelers do not use gold in its pure form; jewelry is usually made from gold alloys. To classify the gold content in an alloy, samples are used. Each sample of gold has its own color, because its shade is influenced by the composition of the alloy.
Electronics
Gold plated connectors.
Photo: Amazon Since gold is a good conductor, it is used in spare parts for electronic devices. For example, there is about 0.034 g of gold inside a mobile phone. In addition, gold is found in many connectors, cables and circuit boards, including computers, televisions and GPS devices.
Medicine
The first thing worth mentioning is dentistry. Gold is considered the best filler for cavities and crowns, bridges and other orthodontic appliances because the metal is malleable and easily molds to the desired shape. Also, gold does not react when mixed with other metals.
Small amounts of gold isotopes are used in some types of radiation therapy, which is often used for cancer.
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beauty
Mask made of the thinnest gold foil.
Photo: Getty Images Gold also has a place in the beauty industry, because... It is a good antioxidant, and gold has also been proven to fight signs of aging. Gold can work on the skin at the cellular level, activating collagen production and plumping the skin.
Everyone has heard about Cleopatra's milk baths, but there is another story - they say that the queen constantly made face masks from pure gold. Today, gold can be found in the composition of many cosmetic products: the same masks, creams, scrubs, peelings, etc. Of course, the content of the noble metal in them is low, and such products are expensive.
Sun protection
Chandrayaan-2 is an interplanetary station for lunar exploration.
Photo: ISRO Another amazing property of this noble metal is protection from ultraviolet rays. The largest area of application of gold for such purposes is astronautics. There is a special “gold foil” that is used to cover parts of spacecraft to protect them from solar radiation. Astronauts' spacesuits are also covered with gold, which allows a person to see, but does not allow harmful rays to pass through.
Cooking
Golden Opulence Ice Cream Garnished with Edible Gold Gold
is truly edible, and some chefs garnish their gourmet dishes with liquid gold. In one of the establishments in New York you can try pizza with pieces of gold, it will cost $2000, and in Abu Dhabi you can drink a golden cappuccino for $20.
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In fact, people have been eating gold since ancient Egypt, believing that the metal was sacred and would give them strength. The harm or benefit of eating gold has not been proven.
Awards
Gold has become a symbol of the award for first place in competitions, championships and other competitions. It is used to make medals for the Olympics, awards for film festivals and music awards, and even at smaller events, winners are often given gold jewelry.
Cold fusion
Nowadays it is impossible to make gold from lead at home - this process is too knowledge-intensive and expensive. This is due to the fact that it is necessary to carry out hot nuclear fusion. That is, it is necessary to reach significant temperatures, which in itself is very costly from an energy point of view.
If we manage to launch cold nuclear fusion, we will be able to obtain the precious metal at relatively low cost. True, in this case the relevant question is how to stop it/keep it under control.
In addition, receiving gold in huge quantities, humanity may stop appreciating it. After all, this metal is valuable not only due to its qualities and characteristics, but also because it exists in limited quantities. And also with cold nuclear fusion, it is necessary to take into account that the transformation of elements of the periodic table can only be carried out in one direction - from right to left. In this case, lead is very well suited for turning it into gold. But this, alas, is still in theory.
What stones go best with gold in jewelry?
18K Gold Carved Ruby Ring by ARTISAN
Gold is so versatile that it goes well with all stones. An exception is aquamarine on white gold - on it it is almost invisible and is lost from attention, but some will like this option. Also, some consider it unacceptable to combine bright red stones (for example, garnet or ruby) with yellow gold. But, again, this is a matter of taste.
Introductory information
Papyrus was found in the tomb of the Egyptian city of Thebes at the beginning of the last century. It contained 111 recipes, among which were those that considered the possibility of obtaining silver and gold. But, alas, this was aimed at creating fakes or coating other, less expensive objects with precious metals.
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Nevertheless, this document showed that alchemy, even in ancient centuries, captured the minds of people thirsting for easy money. Spreading through the Egyptians and Greeks, it was able to gradually take over all of Europe. The greatest practical dawn came in the Middle Ages. At that time, not only scientists, but also state and church officials were interested in alchemy. Thus, in almost every imperial palace one could find “specialized” people who were supposed to receive gold in order to improve the state of the treasury. It was widely believed that this could be done with the help of the philosopher's stone.
