The Discovery and Development of Mercury

Realgar, also known as Chensha, Dansha, or Chisha, is natural mercuric sulfide (HgS), with a bright red color. It has been used as a pigment by people since ancient times. The inscriptions on oracle bones unearthed from the Yin Ruins in China were painted with realgar; in the Old Stone Age, Europeans also used this bright red pigment to decorate caves.

According to ancient Chinese literature, during the reign of Emperor Qin Shi Huang, some nobles had already used mercury in their tombs. For example, the tomb of Qi Huang Gong in Linzi County, Shandong Province, contained mercury in the form of a pool. This means that China had obtained a large amount of mercury by the 7th century BC or earlier. Additionally, a small tube of mercury was also found in Egyptian tombs from 1500 BC.

The ancient paintings made with the pigment prepared from realgar are recorded in the "Fifty-two Prescriptions" unearthed from the Mawangdui Han Tombs in Changsha in 1973. The copying time of this prescription was around the Qin and Han dynasties, and it is one of the oldest discovered Chinese medical prescriptions. It is speculated to have originated in the Warring States period. Four of the prescriptions used mercury. In addition, mercury was also believed by Tibetans to be a good medicine for healing fractures, prolonging life, and maintaining health. Ancient Greece, Egypt, and Rome also believed that mercury could have a beauty-enhancing effect.

Furthermore, in ancient times, alchemists in the West believed that mercury was the embodiment of the properties of gold and had the common characteristics of all metals, being the origin of all metals. Therefore, alchemists from both the East and the West became interested in mercury.
Mercury is a liquid that can dissolve gold. In ancient times, it was widely used to extract placer gold from river sediments. The mercury dissolved in gold could be recovered by distilling off the mercury.

Realgar can be converted into mercury by calcination in the air. However, the mercury generated is volatile and difficult to collect. Moreover, operators may also suffer from mercury poisoning. After continuous improvements, mercury was produced by sealing methods. Some were done in sealed bamboo tubes, and some in sealed stone jars.

The mercury mines in Spain have been exploited since 2500 years ago. At that time, the mining of mercury was monopolized by the mercury mines in Spain, Italy, Slovenia and other places. It was not until the end of the 19th century that the emergence of new mercury mines changed this situation. The mercury from the Almadén mine in Spain was supplied to Europe. In America, Spanish conquistadors developed large amounts of cinnabar mines in Wanakivilca to extract gold. In 1848, miners during the California Gold Rush used mercury from the New Almadén mine in California. The Almadén mine stopped mining in 2003.

In China, the production of mercury in the jasper mines was mainly to recover and expand some old mines left by the old China in the early 1950s. From 1950 to 1952, all major mercury mines in the country were successively taken over by relevant departments. The Tongshan mercury mine in Wan'an was taken over by the Tongren Prefecture in October 1950, and the Dachonglu mercury mine was taken over by it in March 1951. The Huangxian mercury mine in Huanxian was taken over by the Industrial Department of Hunan Province in January 1951. The Danzhai mercury mine in Duyun was taken over by the Duyun Public Security Bureau in May 1952, and the Wuzhuan mercury mine in Wuzhuan was taken over by the Wuzhuan County Public Security Bureau. These old mines that were taken over from mining companies or private joint-stock companies were in a dilapidated state. The state quickly restored and expanded these mines.

With the development of technology, mercury has gradually been widely used in the manufacture of scientific measuring instruments (such as barometers, thermometers, etc.), medicine, catalysts, mercury vapor lamps, electrodes, mercury fulminate, etc., as well as in dentistry and the cosmetics industry. However, as is well known, mercury belongs to toxic metals, so during its extensive application, its harm to the human body and pollution to the environment have gradually attracted global attention. Therefore, on October 10, 2013, Japan was the first to sign the "Minamata Convention", aiming to reduce mercury (commonly known as mercury) emissions worldwide to reduce the harm of mercury to the environment and human health.

Due to the harmful effects of mercury on human health, people have been exploring alternative substances and have found substitutes in many fields. The mercury in traditional thermometers has been replaced by an alloy composed of gallium, indium and tin, and electronic thermometers have gradually replaced traditional ones. Diaphragm and thin-film battery technologies are also replacing mercury battery technologies in chlor-alkali plants. In the United States, mercury has been replaced by lithium, nickel-cadmium and zinc-air batteries in mercury-zinc batteries, and mercury in alkaline batteries has been replaced by indium compounds. Mercury-based germicides in latex paints have also been replaced by organic compounds.

In the United States, mercury is no longer used in the production of batteries and paints. However, some button batteries, cleaning products, fireworks, pesticides, folk medicines, old-fashioned clocks and whitening skin care products and soaps still contain mercury. Every year, the global consumption of mercury is less than 2000 tons, of which about 50% is consumed by China for the production of vinyl chloride monomer based on coal.

Almadén is located in the province of León, Castilla-La Mancha Autonomous Region in southwestern Spain. The mining history of mercury in this area can be traced back to the 7th century BC. At that time, Phoenicians, Romans, and Arabs mined cinnabar there, using it as a coloring agent for paints and cosmetics, but they did not consider it as a raw material for mercury metal. From the 1600s to the 1620s, the mercury production in the Almadén region developed rapidly. In 1645, the Spanish government directly managed the mercury mines there. In the 18th century, the mercury production in this area continued to increase. By the end of the 20th century, it reached 1,500 tons per year. The mercury mining in the Idrija region originated in 1490. In the 16th century, the mining output there was not large, but it developed rapidly in the 17th century. The local area in Idrija is famous for operating mercury stores and infrastructure, as well as the living areas and theaters of miners.

Mercury is a naturally occurring chemical element. Mercury can be naturally released through volcanic eruptions and the weathering of the earth's crust, and naturally circulates among the biosphere, hydrosphere, atmosphere, and lithosphere. Mercury in the atmosphere (90% of which is gaseous mercury) can easily transfer from one region to another and naturally settle in the communities of plants and animals. Mercury is also a toxic chemical element that poisons the human nervous system. However, industrial development has accelerated the emission of mercury and its circulation worldwide, becoming a global pollutant. Regarding the symptoms of mercury poisoning among the miners and their families in Idrija and other long-term effects, records were made as early as the first half of the 15th century in the literature of Swiss toxicologist Paracelsus.

Therefore, after the 20th century, various mercury-producing countries in Europe closed their mercury mines. However, the mercury mining in Almadén and Idrija was of great significance in the economic development of Spain and Slovenia. Therefore, the mining of mercury in these two areas continued until the 21st century. In recent years, the governments of both countries have decided to close their mercury mines to protect the environment, while seeking funding and taking measures to restore the affected areas and solve the major economic and social problems caused by the closure of mercury mines.