Recently, when I walked into the mall, consumers who wanted to buy ** jewelry will obviously notice that ** is much more expensive than before.
At the beginning of December this year, New York and London spot prices both broke through the $2,100 ounce mark. Although it has declined since then, it has reached an all-time high.
The "crazy rise" of the bulk market was also quickly transmitted to the consumer market, and **jewelry** followed by the rise. As one of the symbols of human wealth, every large fluctuation of ** affects the hearts of consumers.
So, why has ** been so precious since ancient times?
The reserves are large but difficult to exploit
According to data released by the U.S. Geological Survey, there are currently about 530,000 tons, of which the proven reserves are 330,000 tons. At first glance, the total reserves of ** resources do not seem to be small, but why is *** still high?
*Just because a large reserve is not enough to make it possible to exploit all of them. Even in today's advanced science and technology, the exploration and exploitation of first-class resources is still a high-difficulty, high-investment and high-cost undertaking.
In the era when human beings lacked advanced technology and large-scale equipment, the first ** that was mined and utilized was usually exposed to the surface of the earth, that is, as fine as sand**. Sand gold deposits are shallow and easily washed by natural rivers, so that the fine gold ore as fine as sand flows into the river and is washed downstream to be salvaged by people. This is also the earliest ** of the word "gold rush".
However, there are three major elements that must be present in an area that can pan for gold: first, it must have sand gold deposits;Secondly, there is also a need for rivers to be used as transport channelsFinally, the geomorphological characteristics of the downstream of the gold mine need to meet the requirements of gold panning, such as relatively flat terrain, slow water flow speed, and shallow river depth. Although there is also sand gold distribution in large water systems such as the Yangtze River and the Yellow River in China, it is difficult to salvage the sand gold in the rivers due to the deep riverbed, fine sand gold particles and low grade.
Buried deep underground rock gold is even more difficult to mine. Finding the exact location of a gold mine before mining is an extremely difficult task.
Mineral resource exploration is a high-risk behavior, which is characterized by large investment, long cycle, high risk and great difficulty. Li Wen, general manager of Shandong ** Geological Exploration Group, said that to discover a gold mine, it needs to go through multiple stages such as survey, exploration, drilling, detailed investigation and exploration. Taking China's largest gold deposit, Xiling Gold Mine, as an example, it took 23 years from survey to exploration.
Large gold mines are usually located anywhere from 100 metres to 100 metres underground. "Prospecting is like fishing, and the mine belt is a school of fish. We didn't know where the fish were on the shore, so we had to drill one hole at a time. It wasn't until we caught our first fish that we had a way to determine the exact location of the fish. Levine said. And with each hole drilled, the exploration cost will increase significantly.
Finding gold is only the first step, and choosing the right mining method is equally important.
For gold mines located in shallower locations below the surface, open-pit mining is an option. With the help of efficient blasting technology, large excavators and mining trucks, among others, professionals can directly mine the ore body by stripping the overburden. If you want to excavate deep mineral deposits, you need to use underground mining technology, and the commonly used methods include empty field method, filling method, etc.
There are two main factors affecting the mining cost: one is the ore reserves, grade, etc., and the other is the mining technology and management level of the enterprise.
Convenient life and wide range of uses
Maybe many people don't know, ** actually "accompany" us every day. It is estimated that a smartphone contains an average of 005 g**. Not only mobile phones, but almost every complex and advanced electronic device contains trace amounts**.
The production of electronic devices is one of the most important industrial uses. The effectiveness and reliability of an electronic device depends largely on the quality of the connections between the various electronic components within it, the key of which are connectors and contact points.
Many electronic devices are prone to oxidation and other undesirable phenomena at the contact points in the low-voltage and low-current working environment. Good conductivity and stability compared to other metals make it an excellent material for manufacturing connectors and contacts in the electronics semiconductor industry.
As a highly efficient conductor of current, it can carry these tiny currents and remain stable for a long time. At the same time, it has good chemical stability and can keep it from corrosion for a long time, which helps to ensure the stable operation of the circuit for a long time. Therefore, in the critical electronic devices of many important equipment, ** is an indispensable raw material.
In addition, in the field of medical and health care, ** also plays an important role. For example, colloidal gold, which exists in colloidal form, has been widely used in virus detection and conception testing.
Lu Wensheng, an associate researcher at the Institute of Chemistry of the Chinese Academy of Sciences, introduced that chloroauric acid can be polymerized into gold particles of a certain size under the action of a reducing agent, and form a stable colloidal state under the action of static electricity, which is colloidal gold.
Colloidal gold has the unique advantage that it can take on a variety of different vibrant colors rather than just gold. This feature is the main reason why colloidal gold is widely used as a variety of medical detection reagents. The surface of colloidal gold particles is able to bind to molecules such as proteins. When antibodies labeled with colloidal gold react with antigens, these markers can accumulate on the carrier at a density that can appear red or purple visible to the naked eye.
Portable testing products such as pregnancy test sticks and new coronavirus antigen detection reagents made by this method have the advantages of convenience and speed, specific sensitivity, strong stability, and intuitive result judgment, and are especially suitable for large-scale testing and large-area census at the grassroots level.
High potential for microbial metallurgy
It not only promotes the progress of modern science and technology, but also promotes the upgrading of mining and extraction technology.
In mines, the ** that humans are able to find is usually scattered throughout the gold layer in other rock compositions. Therefore, metallurgy is actually to "pull" these scattered ** out of the ore through some special methods, and then make it re-form gold nuggets or gold grains.
In the past, smelting was a highly polluting industry. The cyanide and amalgamation refining methods that have been used for hundreds of years have brought significant damage to the environment. These methods are inefficient, have a long cycle, and the relevant agents are in direct contact with the external environment, making it difficult to control pollution, and posing a great threat to surface water, groundwater and soil. Therefore, "detoxification to green" has always been an important development direction of the smelting industry.
It is unimaginable that microorganisms that seem to be unrelated to the best can also play an important role in metallurgy. Researchers have detected biological components on naturally occurring ** surfaces and identified DNA (deoxyribonucleic acid) of 30 species of bacteria in it. One of them is called Rawstom metallica. The researchers added a solution containing gold ions to the culture of the bacterium, and subsequently observed significant gold precipitation. As a result, researchers believe that these bacteria are involved in the formation of natural gold.
However, ** does not contain nutrients, so why can it attract bacteria, and even allow bacteria to participate in the formation of **?
Researchers believe that all kinds of organisms in nature live not so much in the "most suitable" environment as in the "most advantageous" environment. These bacteria choose to survive on ** and participate in the "construction" precisely because they are the only ones who can tolerate the toxicity of gold. This way, other microorganisms will not compete with them for space and nutrients around them.
On this basis, the researchers discovered a representative of the "alchemical microorganism" - metal-resistant copperfish. It is able to convert extracellular gold ions into gold particles through a special enzyme to resist the invasion of gold ions on its own cells. This process is similar to "alchemy". And if this special enzyme is put into the ** solution alone, it can also convert gold ions into gold particles.
Nowadays, microbial metallurgy has become an important research direction of green metallurgy, and there are a large number of examples of practice and application at home and abroad, and related technologies have a wide range of application prospects.