first information on compounds containing mercury, reach us from time immemorial.Aristotle mentions it for the first time in 350 BC, but archaeological evidence suggests an earlier period of application.The main directions of the use of mercury were medicine, art and architecture, manufacture Venetian mirrors, metal processing, and so on. D. Its properties people only find out by experiment that required a lot of time and cost many lives.The fact that mercury is dangerous for humans, it is known from the beginning of its use.Modern methods and techniques of research much more effective and safer, but still a lot about this metal people still do not know.
chemical element
Under normal conditions, the mercury - a heavy liquid is white and silver, it belongs to the metals was proved by Lomonosov and I. Brown in 1759.Scientists have proved that in the solid state it is electrically conductive and can be subjected to forging.Mercury (Hydrargyrum, Hg) in the periodic system of Mendeleev has the atomic number 80, is located in the sixth period, group 2, and belongs to a subgroup of zinc.Translated from the Latin name literally means "silver water", from Old - "to roll."Unique item is already in the fact that the only liquid metal, which in nature is in dispersed form and occurs in the form of compounds.A drop of mercury, roll down the rock - a phenomenon impossible.The molar mass of an element - 200 g / mol, the radius of an atom - 157 pm.
Properties
at 20 ° C relative density of mercury is 13.55 g / cm3, for the process of melting necessary -39 ° C to boiling point - 357 ° C for freezing -38.89 ° C.Increased vapor pressure gives a high evaporation rate.At higher temperatures the mercury vapor are the most dangerous to living organisms, and for this process is not an obstacle water or any other liquid.The most sought-after property in practice - getting amalgam, which is formed by dissolving the metal in mercury.If it turns out a large number of alloy semi-liquid state of aggregation.Mercury easily leaves the compound that is used in the recovery of precious metals from ore.Amalgamation not be metals such as tungsten, iron, molybdenum, vanadium.Chemically mercury - sufficiently resistant member which passes readily in the native state and reacts with oxygen only at high temperatures (300 ° C).When reacted with an acid dissolution only occurs in nitric acid and aqua regia.Metallic mercury is oxidized with sulfur or potassium permanganate.It actively reacts with halogens (iodine, bromine, fluorine, chlorine) and non-metals (selenium, phosphorus, sulfur).Organic compounds with carbon atom (alkyl-mercury) is the most stable form and in natural environment.Methylmercury is considered one of the most toxic organometallic compounds with short chain links.In this state, the mercury hazard to human becomes the highest.
Being in nature
If we consider mercury as a mineral, which is used in many industries and areas of human activity, it is a rare metal.According to experts, in the surface layer of the earth's crust contains only 0.02% of the total amount of said element.Most of the mercury and its compounds are in the waters of the oceans and scattered in the atmosphere.Recent studies show that a high content of this element contains the Earth's mantle.In accordance with this statement there was such a thing as a "breath of mercury Earth."It is the process of degassing upon further evaporation from the surface.The highest mercury emissions comes at a time of volcanic eruptions.In the future, natural and man-made emissions are included in the cycle, which occurs due to the connection with other elements under favorable environmental conditions.The formation and collapse of the mercury vapor poorly studied, but the most probable hypothesis is considered participation of some types of bacteria.But the main problem is methyl and demitil-derived compounds that are actively formed in nature - in air, water (demersal muddy areas or sectors most organic pollution) - without catalysts.Methylmercury has a very high similarity to biological molecules.The more dangerous the mercury - is the ability to accumulate in any living organism due to the ease of penetration and adaptation.
deposits
containing mercury and mercury minerals are more than 100, but the main compound which ensures the profitability of mining acts cinnabar.In percentage terms, it has the following structure: 12-14% sulfur, mercury is 86-88%, with native mercury, gray ores, metacinnabar and so on. D. Are associated primary sulfide minerals.Crystal size cinnabar reach 3-5 cm (maximum), the most common have a size of 0.1-0.3 mm and may contain impurities of zinc, silver, arsenic and the like. D. (20 elements).Ore sites in the world there are about 500, most productive mine in Spain, Slovenia, Italy, Kyrgyzstan.For the treatment of the ore used two basic methods: oxidation at high temperature to release mercury and concentration of starting material followed by processing the resulting concentrate.
Applications
Due to the fact that the danger of mercury proved, with the 70-ies of the XX century, limited its application in medicine.The exception is the thimerosal used for the preservation of vaccines.Amalgam silver today is still found in dentistry, but is actively displaced Reflective seals.The most widespread use of hazardous metal fixed at creation of devices and precision instruments.Mercury vapors are used for fluorescent and quartz lamps.In this case, the feedback depends on the coverage of the transparent body.Due to the unique heat capacity of metallic mercury demand in the production of high-precision measuring instruments - thermometers.The alloys used for the production of position sensors, bearings, sealed switches, actuators, valves, and so on. D. Biocidal paints earlier also contained mercury and used to cover the hull that prevents them from fouling.Chemical industry uses large amounts of salts as a catalyst element in the allocation of acetaldehyde.In agriculture sulemu calomel and used for the treatment of seed - the toxicity of mercury prevents the grains and seeds from pests.In metallurgy, the most in demand of amalgam.Mercury compounds are often used as a catalyst for the electrolytic production of chlorine, alkali metal and active.Gold Miners used this chemical element for processing ore.Mercury and its compounds are used in jewelry, in the manufacture of mirrors and recyclable aluminum.
Toxicity (dangerous than mercury)
a result of anthropogenic activity of man in our environment increases the concentration of toxic substances, pollutants.One such element identified at the first positions on virulence is mercury.The danger to humans of organic and inorganic compounds, and its vapors.This cumulative highly toxic poison that can accumulate in the human body for years or do a time.Affected CNS enzymatic and hematopoietic system, and the degree of poisoning, and the outcome depends on the dose and the method of penetration, the toxicity of the compound exposure time.Chronic mercury poisoning (accumulation of a critical mass of the substance in the body) is characterized by asthenovegetative syndromes, disorders of the nervous system.The first signs are trembling eyelids, fingertips, and then the limbs, tongue and body.With further development of poisoning manifested insomnia, headaches, nausea and disruption of the digestive tract, neurosis, disturbed memory.If there is mercury vapor poisoning, the characteristic symptoms are respiratory diseases.With incessant exposure to the toxic substance which eliminates the system fails, it can cause death.
poisoning mercury salts
fastest flowing and difficult process.Symptoms include headache, metallic taste, bleeding gums, stomatitis, increased urination with a gradual reduction and its complete cessation.In severe form characterized by kidney damage, gastrointestinal tract and liver.If the person survives, and then all will be disabled.Action mercury leads to precipitation of blood proteins and hemolysis of erythrocytes.Against the background of these symptoms occurs, permanent damage to the central nervous system.Such an element, such as mercury, is hazardous to humans in any form of interaction, and the consequences of poisoning may be irreparable: affecting the whole body, they can reflect on the next generation.
Methods penetration poison
main sources of poisoning are air, water, food.Mercury can penetrate the respiratory tract by vaporizing from the surface.Good capacity has the skin and gastrointestinal tract.For poisoning enough to swim in the water, which is contaminated by industrial discharges containing mercury;consume foods with a high content of a chemical element that can get them from infected species (fish, meat).Poisoning by mercury vapor is obtained, usually as a result of professional activity - non-compliance with safety-related data on elements of production.Is no exception poisoning in domestic conditions.This occurs when the improper use of instruments and instruments containing mercury and mercury compounds.
danger of mercury from a thermometer
most commonly used high-precision medical instrument - a thermometer, it is available in every home.Under normal conditions of life most people do not have access to a highly toxic compounds, which include mercury."Smash the thermometer" - this is the most probable situation of interaction with poison.Most of our fellow citizens still use mercury thermometers.This is due primarily to the accuracy of their testimony, and mistrust of the population to new technologies.In case of damage to the thermometer mercury hazard to humans, of course, is but an even greater threat conceals ignorance.If quickly, efficiently and effectively carry out a series of simple manipulations, the injury will be caused if, the minimum
.
Step 1 First, you need to collect all the pieces of broken thermometers and mercury.This is the most time-consuming process, but its performance is dependent on the health of all family members and pets.For proper disposal, you must take a glass jar, which must be tightly closed.Before starting work, removed from the room all the tenants, it is best to go outside or to another room, where there is the possibility of permanent ventilation.The process of collecting drops of mercury can not be carried out using a vacuum cleaner or broom.The latter can crush the larger faction of the metal and ensure a large area of their distribution.When the vacuum cleaner danger is in the process of heating of the engine during operation, and the effect of temperature will accelerate the evaporation of the particles, and this appliances then can not be used for other purposes, it will only be disposed of.
Procedure
- Wear disposable rubber gloves, surgical mask, shoe covers or plastic bags to shoes.
- Carefully inspect the place where the thermometer was broken;If there is a possibility of mercury in the textiles, clothing, carpets, they are tightly packed into a garbage bag and disposed of.
- glass parts going into the prepared container.
- Large drops of mercury using a sheet of paper or needle knitting needles are assembled with the floor surface.
- Armed with a flashlight, or enhance the lighting of the room, it is necessary to expand the search for smaller particles (by the color of the metal it is easy to find).
- carefully inspect the floor cracks, joints flooring, skirting to eliminate possible contamination of smaller droplets.
- in tight spaces mercury is a syringe, which is then subject to disposal.
- Small metal droplets can be collected with adhesive tape, adhesive.
- During the entire work it is necessary to leave in a ventilated area or the street every 20 minutes.
- All items and handy tools used in the collection of mercury must be disposed of along with the contents of the thermometer.
Step 2
After careful mechanical assembly is necessary to make chemical processing facilities.Use can be potassium permanganate (potassium permanganate) - a solution of high concentration (dark color) in the required amount of the treated area.It is imperative to put on new rubber gloves and a mask.All surfaces are treated with the obtained solution using a cloth and having a recess, slot, cracks and joints best fill solution.At 10:00 the next best to leave the surface in a sacred way.After this time, the solution of potassium permanganate is washed off with clean water, then cleaning is performed using detergents and throughout the apartment.The next 6-7 days is required to conduct regular airing of the premises and a daily wet cleaning.To ensure the absence of mercury, you can invite experts with special equipment of the centers of epidemiology.
Treatment of intoxication
WHO identifies the 8 most dangerous substances, the content of which in the atmosphere, food and water must be carefully monitored because of their danger to human life and health.This lead, cadmium, arsenic, tin, iron, copper, zinc and, of course, mercury.Hazard of these elements is very high, and the consequences of poisoning them impossible to stop completely.The mainstay of treatment is a human fence from further contact with the poison.If you slack and non-chronic cases of mercury poisoning she excreted in the feces, urine, sweat.Toxic dose is 0.4 ml, deadly - 100 mg.If you suspect that the interaction with the poison should contact the person who on the basis of test results will determine the degree of intoxication and prescribe treatment.
