Mercury is a chemical element, ranking 80th in the periodic table of elements. Commonly known as mercury. There are also other names such as "Bai Zhuo, slave girl, Zhuo, Shen Jiao, lead essence, red mercury, sand mercury, spirit liquid, clown," and so on. The element symbol Hg, located in the 6th period and IIB group of the periodic table of chemical elements, is the only metal that exists in liquid state at normal temperature and pressure (strictly speaking, gallium (symbol GA, 3 1 element) and cesium (symbol Cs, element 55) are also in liquid state at room temperature (29.76℃ and 28.44℃). Mercury is a silvery white shiny heavy liquid, which is chemically stable and insoluble in acid and alkali. Mercury can evaporate at room temperature, and mercury vapor and mercury compounds are very toxic (chronic). Mercury has a long history and is widely used. In medieval alchemy, it was called the three sacred elements of alchemy together with sulfur and salt.
20 17,101The list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization on October 27th was preliminarily sorted out for reference. Mercury and inorganic mercury compounds are listed as three carcinogens.
Chinese name: Mercury, mercury mbth: Mercury element symbol: Hg relative atomic mass: 200.59 Hazard: extremely toxic (chronic) CASNo. : 7439-97-6 control type: uncontrolled atomic radius: 150( 17 1) (calculated value) /pm atomic volume: 14.82cm3/mol electronic configuration: xe4f (1mol) : 1.02 covalent radius/? : 1.49 melting point: -39℃( 1Pa) boiling point: 356.7℃( 1Pa) brief history of discovery, mineral distribution, mineral deposit, migration and transformation, physical properties, chemical properties, toxicology introduction, medicinal field, pharmacological action, pharmacology, common use. Natural mercury sulfide, also known as cinnabar, has long been used as a red pigment because of its bright red color. According to the fact that Oracle bone inscriptions unearthed in Yin Ruins were painted with cinnabar, it can be proved that China used natural mercury sulfide before history. Mercury migration cycle According to ancient Chinese documents, before the death of Qin Shihuang, some princes had used mercury perfusion in their tombs. For example, Qi Huangong was buried in Linzi County, Shandong Province, and his grave was filled with mercury. That is to say, China had acquired a large amount of mercury in the 7th century BC or earlier. Mercury was also used as a surgical medicine in ancient China. 1973 Fifty-two prescriptions of silk unearthed from Mawangdui Han Tomb in Changsha were copied in Qin and Han Dynasties, and they are the oldest medical prescriptions in China, probably during the Warring States Period. Four of the prescriptions used mercury. For example, a mixture of mercury and realgar is used to treat scabies. Eastern and western alchemists became interested in mercury. Western alchemists believe that mercury is the embodiment of the commonality of all metals-metallicity. What they think of as metallicity is an "element" that constitutes all metals. "Mercury" Regular Script Form Ancient working people in China calcined cinnabar (i.e. mercury sulfide) in the air to obtain mercury. However, the generated mercury is volatile and difficult to collect, and mercury poisoning will occur to operators. Working people in China have accumulated experience in practice and switched to closed mercury production, some in bamboo tubes and some in pomegranate cans. According to the information of western chemical history, a small tube of mercury was found in an Egyptian tomb. According to historical research, it is the product of BC 16 years-BC 15 years. But the working people in ancient China first produced a lot of mercury. Mineral distribution Mineral mercury is a naturally occurring element, which exists in air, water and soil. Mercury is a highly toxic and non-essential element, which widely exists in various environmental media and food chains (especially fish), and its traces are all over the world. The world's mercury resources are about 700,000 tons, with a basic reserve of 300,000 tons. The main countries with mercury reserves and their basic reserves are 90,000 tons in Spain, 69,000 tons in Italy, 8 1400 tons in China and 45,000 tons in Kyrgyzstan. Mercury deposits in the world are mainly distributed in the Tethys-Himalayan tectonic belt. The main type of mercury deposit is carbonate, followed by clastic rock and magmatic rock. Among them, carbonate type is the most important, accounting for 90% of mercury reserves. Mercury minerals are located in the lower CAMBRIAN strata, and their production and enrichment are strictly controlled by structure, rock assemblage and wall rock alteration. The main ore bodies are layered, layered-like, and layered lenticular, which have obvious stratabound characteristics and belong to stratabound deposits. It is recognized as the most typical "layered mercury mine" in China, which is of great significance to mercury exploration and research at home and abroad. The ore is single, mainly cinnabar. The output is mainly dotted and disseminated, followed by pulse and stripe. Good mineral processing and metallurgical properties. Migration and transformation (I) Mercury cycle is a typical heavy metal cycle in an ecosystem. As an element, mercury migrates and transforms in water, soil, atmosphere and biosphere. (2) Main characteristics of mercury migration and transformation: (1) Mercury is the only heavy metal in the ecosystem that can perfect the cycle. After mercury is discharged into water, through the food chain, the concentration of methylmercury in fish polluted by mercury can be tens of thousands of times higher than that in water. (2) The complex process of mercury cycle display includes: particle migration; Sedimentation of dry matter and wet matter; Volcanoes volatilize into the atmosphere; Enter water and precipitate in sludge; Generate methylmercury under that action of bacteria; Enter the organism; Accumulate in organisms. (3) Biomethylation: Under the action of microorganisms, inorganic mercury such as metallic mercury and divalent ion mercury will be transformed into methyl mercury and dimethyl mercury, which is called mercury bionics. (4) Methyl mercury is easily absorbed by human body, and its emission is slow and toxic. This is because methylmercury is easily soluble in lipids; Mercury is not easy to decompose in the body, and it is not easy to cut off because of the carbon-mercury bond in its molecular structure; It is an advanced nerve agent, which accumulates in the brain. Physical properties are the only metal that exists in liquid state at normal temperature and pressure. Melting point -38.87℃, boiling point 356.6℃, density 65438 03.59 g/cm3. Strong cohesion, stable in air, mercury vapor volatilizes at room temperature, and the vapor is highly toxic. Natural mercury is a mixture of seven isotopes of mercury. Mercury is slightly soluble in water, and its solubility in air increases. Mercury is ubiquitous in nature. Generally, animals and plants contain trace amounts of mercury, so there are trace amounts of mercury in our food, which can be metabolized by excreta and hair. Alloy: Mercury is easy to alloy with most common metals, and these alloys are collectively called amalgam (or amalgam). Metals that can alloy with mercury include gold and silver, but cannot alloy with iron, so iron powder has been used to replace mercury. Some other transition metals in the first row are difficult to form alloys, but they do not include manganese, copper and zinc. Other elements that are difficult to alloy with mercury are platinum and other metals. Sodium amalgam is a common reducing agent in organic synthesis and also used in high-pressure sodium lamps. When mercury comes into contact with pure metal of aluminum, it is easy for them to form aluminum amalgam, because aluminum amalgam can destroy the oxide layer that prevents aluminum from further oxidation (brush experiment), so even a small amount of mercury can seriously corrode aluminum. Because of this, in most cases, mercury can't be taken on the plane, because it is easy to alloy with exposed aluminum parts on the plane, causing danger. Liquid state: As a metal, mercury exists strangely in liquid state at room temperature. Relativistic contraction effect theory can provide an explanation for this unusual phenomenon. Similar to gold, the 6s orbit of mercury shrinks and tends to be stable, which leads to an effect called "inert electron pair": the 6s 2 shell of mercury is inert in the bonding process. It can be seen that the excitation energy of mercury is far more than that of cadmium and zinc. According to the general periodic law, the energy interval should decrease with the increase of principal quantum number. Therefore, it is expected that the energy range from zinc to cadmium will become smaller, but the energy range from cadmium to mercury will suddenly become larger. Here we can see again that it is the relativistic contraction effect that makes the full 6s 2 shell stable, so the 6s 2 6p energy range of Mercury suddenly increases. As long as the required excitation energy is not obtained, a strong bond cannot be formed between the mercury atom and the inert 6s 2 shell. The ground state Hg 2 is only maintained by van der Waals force, so metallic mercury is liquid at room temperature. Chemically soluble in nitric acid and hot concentrated sulfuric acid, mercury nitrate and mercury sulfate are generated respectively, and mercurous salts appear when mercury is excessive. It can dissolve many metals and form alloys, which is called amalgam. The valence is+1 and +2. Like silver, mercury can react with hydrogen sulfide in the air. Mercury has a constant volume expansion coefficient, its metal activity is lower than that of zinc and cadmium, and it cannot replace hydrogen in acidic solutions. Generally, the valence of mercury compounds is+1 or +2. The mercury compounds with valence of +4 are only mercury tetrafluoride, and the mercury compounds with valence of +3 do not exist. Introduction to Toxicology It should be noted that a small amount of liquid mercury is generally nontoxic if swallowed (it is reported that it will form organic compounds in organisms), but mercury vapor and mercury salts (except some mercury sulfide with extremely low solubility) are highly toxic, which can cause brain and liver damage after oral administration, inhalation or contact. Generally speaking, the thermometer uses alcohol instead of mercury, and the thermometer used in People's Republic of China (PRC) (China) (excluding Hongkong, Macau and Taiwan Province) still uses mercury. China plans to phase out the use of mercury thermometers by 20 15 years ago. The most dangerous mercury organic compound is dimethyl mercury [(CH 3) 2 Hg], and only a few microliters (10 -9 m 3 or 10 -6 dm 3 or 10-3 cm 3) of dimethyl mercury can cause death. Mercury can accumulate in organisms and be easily absorbed by skin, respiratory tract and digestive tract. Minamata disease is a kind of mercury poisoning. Mercury can destroy the central nervous system and have adverse effects on oral cavity, mucosa and teeth. Long-term exposure to high mercury can lead to brain damage and death. Although the boiling point of mercury is very high, the saturated mercury vapor at room temperature has reached several times the toxic dose. Mercury in the medical field of Minamata disease (mercury poisoning) comes from this meridian. Materia Medica: Mercury, the cloud of Classic comes from cinnabar, but coarse cinnabar is collected from rocks, with sand in the furnace, water at the bottom and angels on the top. When calcined with fire, there is smoke flying on the top and mercury sliding on the bottom, and the color is small and white. As for the newcomers from Xiqiang, it is also burned like this. However, there are many things in the mountains. As for a self-fractured mountain, people collect sand and stones, which are as big as buckets and can be burned and calcined, so the mercury in the west is more than that in the south. Materia Medica: mercury, lead solidification, sulfur solidification, jujube powder. Calcined into oily powder and pasty powder by other methods. Splash and kill lice. Outline: Mercury, if sprinkled on the ground, will be collected with pepper or tea powder. "Classic meets the original": Mercury, with heavy malice, is not suitable for people's stomach. Today, some people eat mercury by mistake and their stomachs fall heavily. It is also a method to use 2 Jin of pig fat, cut into small pieces and bake them, and mix them with raw honey. Pharmacological action Mercury (mercury) compounds have the functions of disinfection, laxative and diuresis, and are not used or rarely used now. Simple mercury does not cause pharmacological effects, and free mercury ions can combine with hydrophobic groups to interfere with cell metabolism and function. Elemental mercury can not be absorbed from gastrointestinal tract, but its surface can form oxide or sulfide when exposed to air, so it sometimes causes mild diarrhea and diuresis after swallowing. Most people who swallow mercury have no symptoms, and mercury is excreted from feces. A few people may have certain symptoms, and a very few (sensitive or other unknown reasons) may lead to immediate death. Mercury is a prototoxin, which can combine with sulfur and hydrogen groups in respiratory enzymes of pathogenic microorganisms, inhibit their viability, and finally suffocate them. Mercury is excreted mainly through the kidney, followed by the large intestine. Medical (toxic) mercury has corrosive effect on digestive tract, and has adverse effects on kidneys and capillaries. Acute poisoning is mostly caused by taking mercury chloride by mistake, and the symptoms are digestive tract corrosion. Renal damage after absorption leads to urine closure and capillary damage, resulting in plasma loss and even shock. Early application of dimercaprol and other symptomatic measures is the most effective. Chronic poisoning is commonly seen in industrial poisoning, resulting in stomatitis and toxic encephalopathy, the latter manifested as mental symptoms such as depression and atrophy and muscle tremor. Common prescriptions for scabies are not bad after years: one or two pieces of mercury, one or two pieces of alum, one or two pieces of cnidium fruit, one or two pieces of realgar and one or two pieces of shavings. Apply the medicine and add half a catty of pig fat. The water star is used up. Apply it every three days. ("Sheng Hui Fang" Mercury Ointment) Treatment of dry tinea: mercury, Hu San. Study and order it to be drawn. ("After Elbow") Treating heat sores and scabies, itching and pain can't be ninja: mercury, turnips. Crispy and coated. Treatment of toxic ulcer in Myrica rubra: mercury, black lead, Huang Dan, frankincense and myrrh. For the end, use a paper roll as a stick, light it with oil, and sun (smoke) it three times. ("Outline") Treatment of hemorrhoids and insect itching in the valley: two pieces of mercury and two pieces of jujube paste. In harmony with the research, it looks like a jujube, wrapped in a thin sheet and collected. If there is pain, add three kinds of powder and make pills. (Shi Mei Ji Fang) Treatment of vitiligo: Mercury swab will make the hot air disappear, and the frequency of wiping will stop. (prescription) treatment of underarm body odor: mercury, Hu San. Apply two flavors, grind them and coat them with fat. Highly toxic drugs should not be taken orally, especially for pregnant women. External use should not be excessive or used for a long time to avoid poisoning. Materia Medica: People suffering from scabies are often coated with mercury, which is slippery and heavy, so be careful when going straight into the meat. Classic of Materia Medica: Headache must not be used, for fear of entering the tendons and collaterals will slow down the muscles and bones, but it is suitable for external application and not for internal administration. Applications The most common uses of mercury are the manufacture of industrial chemicals and for electronic or electrical products. Mercury is also used in thermometers, especially for measuring high temperatures. More and more gaseous mercury is still used to make fluorescent lamps, but many other applications are gradually phased out due to health and safety problems, and replaced by Galinstein alloy with less toxicity but much higher price. Besides, mercury has other uses: it can decompose gold in minerals, so it is often used in gold mines. Instruments such as barometer and diffusion pump. The triple point is -38.8344℃, which is a standard point of temperature. Gaseous mercury is used in mercury vapor lamps. A telescope use to make liquid mirrors. The price of a telescope that uses liquid to form a paraboloid shape as the main mirror of astronomical observation is one-third of that of an ordinary telescope. Other uses: mercury switches, pesticides, preservatives in the production of chlorine and potassium hydroxide, and used as electrodes, batteries and catalysts in some electrolytic equipment. Dental amalgam dental filler mercury and its compounds have been used in medicine, but they are not as common as before, because the toxicity of mercury and its compounds has been more widely recognized. Mercury is an important element in making dental filling materials. Thiomersal is an organic preservative used in vaccines, although its use has been banned. Another mercury compound, bromomercuric red, is an external disinfectant used for micro-incision and surface trauma; It is still used in some countries. Thiomersal is a cosmetic, which is widely used to make eyebrow cream. In 2008, Minnesota became the first state in the United States to ban the use of mercury in cosmetics. Preparation method In nature, mercury mostly exists in the form of compounds, and mercury is copper and sulfur-loving, so mercury is mostly distributed in the form of mercury sulfide (cinnabar). In ancient times, people have mastered the method of extracting mercury from cinnabar, that is, calcining in air, collecting evaporated mercury vapor and condensing to obtain metallic mercury. Cinnabar is heated in the airflow, and the vapor obtained is condensed to obtain mercury. Roast cinnabar in the air or heat it with quicklime. Matters needing attention: Determination of total mercury by atomic fluorescence spectrometry: Principle: After the sample is digested by acid heating, in acidic medium, the mercury in the sample is reduced to atomic mercury by potassium borohydride (KBH 4) or sodium borohydride (NaBH 4), which is carried into the atomizer by carrier gas (argon). Under the irradiation of a special mercury hollow cathode lamp, the mercury atoms in the ground state are excited to a high energy state, and then return to the ground state after inactivation, emitting light with characteristic wavelength. Cold atomic absorption spectrometry: Principle: Mercury vapor has a strong absorption on the resonance line with the wavelength of 253.7nm. After acid digestion or catalytic acid digestion, the mercury in the sample is converted into ionic state, and stannous chloride is reduced to elemental mercury in strong acid medium. Nitrogen or dry air is used as carrier to blow elemental mercury into mercury analyzer for cold atomic absorption determination. In a certain concentration range, the absorption value is directly proportional to the mercury content, which is more quantitative than the standard series. Dithizone colorimetry: Principle: After the sample is digested, in acidic solution, mercury ions can form orange-red complex with dithizone, which is dissolved in chloroform and compared with the standard series. Determination of methylmercury by gas chromatography: Principle: The methylmercury in the sample is ground with sodium chloride, then hydrochloric acid containing copper ions (1+ 1 1) is added, completely extracted, centrifuged or filtered, the supernatant is adjusted to a certain acidity, adsorbed with sulfhydryl cotton, and then eluted with hydrochloric acid (1+5). Cold atomic absorption spectrometry: principle: gas chromatography. However, in alkaline medium, mercury meter is quantitative compared with standard series. Widely used thermometers, sphygmomanometers and other equipment have caused indoor mercury pollution and other environmental problems. Don't panic when you break the mercury thermometer indoors. You can immediately put the broken mercury beads visible to the naked eye on paper (because of the great cohesion of mercury, it is extremely unscientific and irresponsible to use cotton swabs to pick up mercury) and put them in a sealed water bottle. If there are tiny mercury beads, they can be pushed together with paper, and the mercury will automatically gather into small balls and then be collected. For the sake of safety, in the case of some simple chemicals, nitric acid can be used to wipe the ground polluted by mercury to completely eliminate mercury pollution. The method of covering with sulfur powder is absolutely not allowed, because mercury is difficult to combine with sulfide at room temperature and cannot remove mercury pollution. In order to completely remove mercury pollution, we can fumigate the room with iodine vapor for many times until the cuprous iodide test paper does not change color. The experiment shows that the daily mercury leakage can be collected with transparent tape commonly used at home, and the effect is better than paper. Mercury leakage from thermometers and sphygmomanometers can be handled in this way.