Mercury is extremely important metal that is used in virtually all industrial sectors.Therefore, many countries are rapidly developing industry and mercury expanded its search for deposits.How important is the use of mercury in modern industry - try to understand this article.
What is mercury
This is a chemical element, and the only metal that is liquid at normal temperatures.Fluid gray - that looks like mercury, a photo of which is shown below.
solidify mercury can only at very low temperatures.Medieval alchemists could not get hardening of the metal.And only in 1759 the Russian academician Mikhail Lomonosov and I. Brown managed to do it.The fact that in the year in Russia were severe frosts, and with the help of special mixtures, scientists have lowered the temperature to -56ºS.Under such conditions, the mercury was frozen and was similar to the metal.After a long period of time, other alchemists discovered that mercury Superconducting effect when the temperature dropped to -270ºS.
Mercury in the history of mankind
Mercury is known to man since ancient times.The first mentions of it are found in the records of the V century BC.e.A lot of Hg was investigated in India and China.The most ancient Indian school of alchemy known as "Rasayana" or "the way of mercury."It is engaged in the development of therapeutic drugs, and various potions.
ancients mercury found in nature as cinnabar.They used it as the red dye.The name "cinnabar" is associated with an ancient legend and means "dragon's blood".This characteristic of mercury is associated with religious beliefs.At that time, people believed that the blood of the slain in the mountains sacred creatures - the dragon.Therefore, mercury is considered curative agent, the ability to treat patients.One of these therapeutic agents was a mercury ointment.
ancient alchemists considered mercury is the basis of all metals and their vitality.They were convinced that mercury and sulfur can produce gold.But after numerous tests and experiments, it became clear that nothing will come of this idea.How many scientists were killed trying to discover the formula for creating gold.These studies continued until the 30-ies of XX century, until science began to develop rapidly.As a result of radioactive decay, scientists have stable isotopes of mercury from gold, but they were very few.And the price of the metal is very high.
How to extract mercury
main and practically the only industrial source of mercury is a mineral cinnabar.It consists of 86% of the mercury sulfide, other components - impurities of other minerals.Generally cinnabar looks solid precipitates rich in impurities, and resembles grains of irregular shape.Rare rhombohedral shaped crystals, bipyramidal shape.Sometimes found counterparts.
metallic mercury from cinnabar prepared by heating in an open tube, which provides contact with oxygen.During heating, little mercury droplets flow down along the cold walls.Generally orebodies occur at shallow depths and are associated with quartzites, limestone, dolomite and shale.The world's largest deposits of mercury are in Spain, the USA, Yugoslavia, Slovenia, Tajikistan, Kyrgyzstan.Large crystals of mercury ore mined in southern China.
Basic properties of mercury
This mineral has unique properties that have made use of mercury in the modern industry, an important element of it.Mercury is considered toxic and dangerous metal.But its physical and chemical properties in many areas of human activity are essential.
physical properties
Mercury refers to the diamagnetic, since it can form solid alloys with other metals and liquid compounds - amalgam.Pour the mercury is -38,83ºS and metal boils at 356.73 ° C.It evaporates at room temperature.Another important characteristic of mercury - it is diamagnetic.This means that collect liquid metal beads ordinary magnet is impossible.Chemical properties
As the noble metals, mercury is stable in dry air.It reacts with acids, salts, nonmetals.With water, alkalis and acids, non-oxidizing mercury is not responding.At temperatures above 300 ° C it reacts with oxygen to form mercuric oxide.
The use of mercury in the modern industry
In the Middle Ages the liquid metal is actively used in medicine for the amalgamation and manufacturing of different devices.Nowadays it is impossible to find a sector of the economy that does not use mercury.Properties and application of this mineral described by scientists from around the world in numerous scientific studies.
Thus, mercury is used in agriculture for seed mordant.In chemical industry it is used as a catalyst for the production of acetylene acetaldehyde.The use of mercury cathodes allows you to select from common salt caustic soda and chlorine.
Mercury is an essential component in the manufacture of paints for the underwater part of the vessels.The fact that the living microorganisms in sea water are attached to the bottoms of ships and contribute to corrosion and wear of metal parts.Mercury in paints under the influence of maritime chlorine forms sulemu that poisons harmful bacteria.
Mercury is used even in the production of felt.Available in its composition salt perfectly degreased fluff.Safer alternatives that would give the same effect is not found.Also, the mercury acts as a catalyst in organic synthesis in the leather tanning process.
As mentioned, the mercury has always been used in medicine.Today, on this basis produce antiseptic and diuretic drugs.A mercury ointment was prepared in ancient India, a recipe that has survived to the present day.Because of the properties of dissolving other metals (tin, silver) is used for the manufacture of mercury dental fillings.
The use of mercury in the industry is also linked to its ability to evaporate at room temperature.For example, in petroleum refining.Thus, evaporation temperature control helps metal refining processes.
Mercury devices
Physical and chemical properties are the main reason for which the use of mercury in different devices and machines.Couples mercury metal used in turbines.Such systems are particularly advantageous when in the assembly a little water and the cooling mechanism is solely air.
used in electrical rectifiers with liquid mercury cathode.They allow you to convert three-phase AC electric power to DC power.Even in astronomy to use mercury devices - horizons.They have a special vessel with molten metal, the surface of which serves as a mirror during observations of the cosmos.Also, the use of mercury in the modern industry manifests itself in the production of different diffusion pumps, breakers, thermometers.
in many branches of medicine using a mercury-quartz lamp, which is irradiated with ultraviolet rays.It is also an indispensable medical tool is well-known thermometer for measuring body temperature.
How much is mercury: the price on the world market
Price mercury is formed on the same principle as that of other metals.Thus, the cost of this mineral depends on the size and purity of the proposed supply of mercury.On the world market price for mercury, the last six months has dropped substantially.So, if the average price at the end of 2014 amounted to US $ 75 / kg in March 2015 - US $ 55 / kg.But free to buy the liquid metal is almost impossible, since mercury is a chemically hazardous substances.Even the disposal of the spilled mercury need to pay a certain amount.
As for products that contain mercury, their value depends on the amount of metal and other production costs.For example, very cheap is a mercury thermometer.Price pharmacies ranges from 25 to 50 rubles.
danger of mercury for health
Despite the widespread use of mercury in industry, it is considered very dangerous chemical.According to the criteria of harm to the life and health of mercury belongs to the first class of danger.Typically, mercury is ingested by inhalation of its vapors, which are odorless.That mercury vapor are the most dangerous.
to cause severe poisoning and health problems, quite the impact a small number of the mineral.During intoxication in most affects the lungs, kidneys, immune, nervous, digestive system, eyes and skin.
Depending on the cause and nature of poisoning distinguish mild, acute and chronic forms.Easy toxication occurs when food poisoning.After the accident in the chemical industry or as a result of safety violations manifested acute form of poisoning.In this case, the patient is reduced mental activity, exhaustion, can appear convulsions, vision loss, baldness, and even complete paralysis.In severe cases of acute poisoning may lead to death.Chronic poisoning is caused by constant exposure to mercury and can manifest itself for a long time after the cessation of work with it.People with this form of the disease increases the risk of hypertension, tuberculosis and atherosclerosis.There are cases where chronic toxication causes mental disorders.
especially careful with mercury devices should be treated pregnant women.Mercury vapors are a major threat to the development of the fetus.If there are children in the house, it is better to replace conventional mercury thermometers electronic.
Disposal of mercury-containing waste
Widespread use of mercury contributes to its high concentration of vapor in the atmosphere of large cities.Now everywhere used fluorescent lamps, which contain from 30 to 300 mg of the molten metal.And in some lamps it is several times greater.According to statistics, each year about 100 million. These lamps become unusable and require processing.Only a small part of them passed special disposal, and the rest just go to the dump, where the destruction of the integrity of the glass mercury into the atmosphere.
addition, mercury is used in the manufacture of batteries and cells, which basically does not recycled.In this way, for the year to landfill it gets about 40 tons of mercury.This figure is very high, so the problem of disposal of mercury-containing items is very serious.Uncontrolled handling of mercury waste, irresponsible attitude to devices containing the liquid metal endangers the health and lives of people.Everyone knows what kind of trouble can bring a conventional mercury thermometer.Price inept handling may be worth living.
Now all governments are working on the issue of recycling of mercury-containing waste.For this purpose, there are special companies that are engaged in the collection of unusable equipment and mercury items.They divide them into components (caps, glass, metal) and processed.Because each type of waste generated blocks that are packed into special containers (cases, plastic bags, cans) and delivered to the place of processing.
