Where is arsenic produced and sold? Dangerous element arsenic - areas of application

Arsenic

ARSENIC-A; m.

1. The chemical element (As) is a solid, toxic substance of a shiny gray color that is part of many minerals. Arsenic oxide. Obtaining arsenic.

2. A medicinal product containing this substance or its compounds (used as a general tonic, antimicrobial, etc.). Treatment with arsenic. The effects of arsenic on nerve endings.

◁ Arsenic, oh, oh. M connections. M acid. M. drug. Mth poisoning. Arsenic, oh, oh. Outdated Arsenic, oh, oh. ● Russian name This element comes from the word “mouse”, because. arsenic was widely used to kill rats and mice.

(lat. Arsenicum), chemical element Group V periodic table. The Russian name comes from “mouse” (arsenic preparations were used to exterminate mice and rats). Forms several modifications. Ordinary arsenic (the so-called metallic, or gray) is fragile crystals with a silvery sheen; density 5.74 g/cm 3 , sublimes at 615°C. In air it oxidizes and fades. Extracted from sulfide ores (minerals arsenopyrite, orpiment, realgar). Component of alloys with copper, lead, tin, etc. and semiconductor materials. Arsenic compounds are physiologically active and toxic; served as one of the first insecticides (see, for example, Metal Arsenates). Inorganic arsenic compounds are used in medicine as general strengthening and tonic agents, while organic compounds are used as antimicrobial and antiprotozoal compounds (in the treatment of syphilis, amoebiasis, etc.).

ARSENIC (Latin Arsenicum, from the Greek arsen - strong), As (read “arsenicum”), a chemical element with atomic number 33, atomic mass 74.9216. One occurs in nature stable isotope 75 As. Located in group VA in the 4th period of the periodic table of elements. Electronic configuration of outer layer 4 s 2 p 3 . Oxidation states +3, +5, –3 (valency III, V).
Atomic radius 0.148 nm. The radius of the As 3- ion is 0.191 nm, the As 3+ ion is 0.072 nm ( coordination number 4), As 5+ ion 0.047 nm (6). The sequential ionization energies are 9.82, 18.62, 28.35, 50.1 and 62.6 eV. Pauling electronegativity (cm. PAULING Linus) 2.1. Non-metal.
Historical reference
Arsenic has been known to mankind since ancient times, when orpiment minerals were used as dyes. (cm. AURIPIGMENT) As 2 S 3 and realgar (cm. REALGAR) As 4 S 4 (mentions about them are found in Aristotle) (cm. ARISTOTLE).
Alchemists, when calcining arsenic sulfides in air, noted that the formation of the so-called white oxide As 2 O 3:
2As 2 S 3 +9O 2 =2As2O 3 +6SO 2
This oxide is a strong poison; it dissolves in water and wine.
As was first obtained in free form by the German alchemist A. von Boldstndt in the 13th century by heating arsenic oxide with coal:
As 2 O 3 +3С=2As+3СО
To depict arsenic, they used the sign of a writhing snake with an open mouth.
Being in nature
Arsenic is a trace element. The content in the earth's crust is 1.7·10–4% by mass. There are 160 known arsenic-containing minerals. Rarely found in its native state. Mineral having industrial value- arsenopyrite (cm. ARSENOPYRITE) FeAsS. As is often found in lead, copper and silver ores.
Receipt
The enriched ore is subjected to oxidative roasting, then volatile As 2 O 3 is sublimated. This oxide is reduced with carbon. To purify As, it is distilled in a vacuum, then converted into volatile chloride AsCl 3, which is reduced with hydrogen (cm. HYDROGEN). The resulting arsenic contains 10 -5 -10 -6% impurities by weight.
Physical and chemical properties
Arsenic is a gray brittle substance with a metallic luster (a-arsenic) with a rhombohedral crystal lattice, a= 0.4135 nm and a = 54.13°. Density 5.74 kg/dm3.
When heated to 600°C, As sublimates. When the vapor is cooled, a new modification appears - yellow arsenic. Above 270°C, all forms of As transform into black arsenic.
As can be melted only in sealed ampoules under pressure. Melting point 817°C at pressure saturated vapors 3.6 MPa.
The structure of gray arsenic is similar to the structure of gray antimony and is similar in structure to black phosphorus.
Arsenic is chemically active. When stored in air, powdered As ignites to form acidic oxide As 2 O 3 . This oxide exists in vapors in the form of As 4 O 6 dimers.
By carefully dehydrating arsenic acid H 3 AsO 4 the highest acid oxide arsenic As 2 O 5, which easily releases oxygen when heated (cm. OXYGEN), turning into As 2 O 3 .
The oxide As 2 O 3 corresponds to orthoarsenic H 3 AsO 3 and metaarsenic, existing only in solutions weak acids HASO2. Their salts are arsenates.
Diluted Nitric acid (cm. NITRIC ACID) oxidizes As to H 3 AsO 3, concentrated nitric acid - to H 3 AsO 4. As does not react with alkalis and dissolves in water.
When As and H 2 are heated, arsine gas is formed (cm. ARSENIC HYDRIDE) AsH3. With fluoride (cm. FLUORINE) and chlorine (cm. CHLORINE) As interacts with autoignition. When As interacts with sulfur (cm. SULFUR), selenium (cm. SELENIUM) and tellurium (cm. TELLURIUM) chalcogenides are formed: (cm. CHALCOGENIDES) As 2 S 5, As 2 S 3, As 4 S 4, As 2 Se 3, As 2 Te 3, existing in a glassy state. They are semiconductors.
With many metals, As forms arsenides (cm. ARSENIDES). Gallium arsenide GaAs and indium InAs - semiconductors (cm. SEMICONDUCTORS).
Known big number organic compounds arsenic, in which there is a chemical bond As - C: organoarsines R n AsH 3-n (n= 1.3), tetraorganodiarsines R 2 As - AsR 2 and others.
Application
As of high purity is used for the synthesis of semiconductor materials. As is sometimes added to steels as an alloying additive.
In 1909, German microbiologist P. Ehrlich (cm. EHRLICH Paul) received "drug 606" effective medicine from malaria, syphilis, relapsing fever.
Physiological action
Arsenic and all its compounds are poisonous. In acute arsenic poisoning, vomiting, abdominal pain, diarrhea, central depression are observed. nervous system. Help and antidotes for arsenic poisoning: reception aqueous solutions Na 2 S 2 O 3 . Gastric lavage, taking milk and cottage cheese; a specific antidote is unithiol. The maximum permissible concentration in the air for arsenic is 0.5 mg/m 3. Work with arsenic in sealed boxes using protective clothing. Due to their high toxicity, arsenic compounds were used by Germany as poisonous agents in the First World War.
In areas where there is an excess of arsenic in the soil and water, it accumulates in the thyroid gland in people and causes endemic goiter.

encyclopedic Dictionary. 2009 .

See what “arsenic” is in other dictionaries:

ARSENIC- (Arsenum, Arsenium, Arsenicum), solid metalloid, symbol. As; at. V. 74.96. In the periodic table of elements it occupies the 33rd place in order, in the 5th row of group V. Natural compounds of M. with sulfur (realgar and orpiment) were known back in... ... Great Medical Encyclopedia

ARSENIC- see ARSENIC (As). Since arsenic and its compounds are widely used in national economy, it is found in wastewater from various industries: metallurgical, chemical-pharmaceutical, textile, glass, leather, chemical... Fish Diseases: A Guide

Arsenic- (crude arsenic) is solid, extracted from natural arsenopyrites. It exists in two main forms: a) ordinary, so-called metallic arsenic, in the form of shiny steel-colored crystals, fragile, not ... Official terminology

- (symbol As), a poisonous semi-metallic element of the fifth group of the periodic table; was probably obtained in 1250. Compounds containing arsenic are used as poison for rodents, insects and as a weed killer. They are also used... Scientific and technical encyclopedic dictionary

- (Arsenium), As, chemical element of group V of the periodic system, atomic number 33, atomic mass 74.9216; non-metal grey, yellow or black, melting point 817 °C, sublimes at 615 °C. Arsenic is used to produce semiconductor... ... Modern encyclopedia

Arsenic- (Arsenium), As, chemical element of group V of the periodic system, atomic number 33, atomic mass 74.9216; non-metal grey, yellow or black, melting point 817 °C, sublimes at 615 °C. Arsenic is used to produce semiconductor... ... Illustrated Encyclopedic Dictionary

ARSENIC- chem. element, symbol As (lat. Arsenicum), at. n. 33, at. m. 74.92; non-metal, exists in several allotropic modifications, density 5720 kg/m3. Under normal conditions, the most chemically resistant is the so-called metallic, or gray, arsenic.... ... Big Polytechnic Encyclopedia

- (lat. Arsenicum) As, chemical element of group V of the periodic table, atomic number 33, atomic mass 74.9216. Russian name from mouse (arsenic preparations were used to exterminate mice and rats). Forms several modifications. Ordinary arsenic... Big Encyclopedic Dictionary

ARSENIC, arsenic, pl. no, husband 1. A chemical element, a solid substance, poisonous in large doses, usually found in various minerals, used. for chemical, technical and medical purposes. 2. The drug of this substance prescribed for... ... Dictionary Ushakova

Arsenic(um) Dictionary of Russian synonyms. arsenic noun, number of synonyms: 12 arsenic (2) arsenicum ... Synonym dictionary

As- has been known to mankind since ancient times. Already the great Aristotle mentioned the chemical element arsenic in natural compounds. In addition, the possibility of producing its sulfur variety by calcination is described by Dioscorides in the first century BC.

Later, European steelmakers encountered this element when working with ore containing arsenic. Alchemists studied it very closely. This attention was explained by the fact that, like sulfur and mercury, it belonged to the elemental elements that are the basis of all metals.

The ability of arsenic to change the color of copper alloys to white was perceived by professors modern chemistry like the metamorphosis of copper into silver. Nowadays, not a single laboratory in the world can do without this element.

As is present everywhere. Even a smoked cigarette contains it, which, among other things, makes smoking harmful.

History of discovery

The discovery of arsenic on a metal base dates back to the eighteenth century, however, the method of obtaining the element using sublimation was discovered only towards the end of the seventeenth. During this period, the chemist Scheele discovered arsenic acid, as well as the hydrogen present in it.

The study of organic compounds containing As began with the chemist Kade. In the middle of the eighteenth century, he received the first organic compound based on it - “Cadet Liquid”. The structure was disassembled into its components only after eighty years by another famous chemist, Bunsen.

There are still debates about who should give the palm of discovery of the element in its pure form. This achievement is attributed to the merits of Albertus Magnus. It was recognized as a chemical element by Lavoisier in 1789.

Production and applications

Modern experts know about two hundred minerals that contain arsenic. In the vast majority of cases, it is found in ores containing copper, silver or lead. However, the mineral of primary importance to the industry is pyrite containing arsenic.

There are several methods for producing As on an industrial scale. The main type of production was the roasting of arsenopyrite. Next, the oxide is reduced from it using anthracite.

However most of raw materials with this method are converted into white arsenic.

Arsenic in the dental field

This chemical element is not only poison, but also medicine.

The use of arsenic in dentistry in the form of a paste has not lost its significance due to the strong necrotic effect of the substance on the affected tissues.

It is used in the following cases:

• If the patient does not accept anesthetics;
• In cases of contraindications to anesthetic drugs;
• When curing toothache in children.

The main condition for using it in dental clinics is a fully formed root system. Therefore, the “children’s” version of application is not so common.

As in industry

The chemical element arsenic is used in many areas of production, among which several main areas can be distinguished:

• Metallurgy;
• Electrical Engineering;
• Leather processing;
• Textile industry;
• Pyrotechnics;
• Glass production.

Metallurgy- used for alloying lead alloys used for making shot. This alloy with the addition of As in the tower version of production makes it possible to obtain ideal spherical pellet shapes. In addition, its strength increases.

Electrical engineering– highly purified arsenic (up to 99%) is used for the manufacture of a number of necessary semiconductor components.

Textile industry- used as a dye.

Leather industry– in this area it is used as a reagent to destroy stubble on the skin.

Pyrotechnics– the mineral realgar, which is arsenic monosulfide, is used to make “Greek” fire, which is obtained by igniting a mixture of it with sulfur and saltpeter. This chemical compound produces a bright white flame.

Glasswork- As trioxide makes it possible to obtain products with zero transparency. Meanwhile, small additions of the component, on the contrary, brighten it. This element still remains part of the production of some glasses.

For example:

• "Vienna"
• used in thermometers;
• Imitation crystal.

In addition, arsenic is also used in agriculture as a fertilizer. Home method use is rat poison. Now it is made on the basis of other components.

Eating is strictly prohibited.

Arsenic in the fight against leukemia

Known to poisoners Arsenic's ability to kill cells is now being used in noble purposes. This chemical element is widely used to treat cancer, primarily leukemia.

Leukemia is characterized by tumor formation due to bone marrow replication. In the absence of timely treatment, its volume increases. For this reason, metastases arise and grow in all parts of the body. The As element helps cure even a severe form of the disease.

It effectively neutralizes the excessive proliferation of leukocytes, stimulates rapid and quality education red cells. All this allows you to positively influence the recovery process. When treating with this dangerous element, clear instructions must be followed. After all, the final price is human life.

Possible causes of poisoning

Nowadays there is big risk be poisoned by arsenic. None of the workers in production are immune from various surprises. When using As-based substances in domestic conditions, there is also a possibility of accidental entry into the human body.

Sometimes cases of intentional poisoning are recorded - criminal offenses or suicide. These episodes can be classified as acute forms of intoxication.

There is a possibility of poisoning during medical exposure small doses. Such poisoning is considered chronic cases.

A separate group of intoxication with this chemical element is the subacute category. When a person is present in places where there is a large concentration of adamsite.

It is used by police in some countries to disperse demonstrations. Martial ones are divided into several categories, including sternites. Arsenic is one of them. Such substances are irritating to the human respiratory system.

The effect of arsenic on the body

The element has the ability to quickly penetrate the human body, but it is very difficult to remove it.

Poisoning occurs in the following ways:

• Skin;
• Lungs;
• Gastrointestinal tract.

It is worth noting that inorganic components arsenic is absorbed much faster than organic matter.

The greatest danger to humans is arsine in the gaseous state; it does not smell, so for its industrial production it is necessary to make special additives that have a persistent garlic “aroma.” Arsenic hydrogen is also dangerous.

Poisoning occurs very quickly. Within 24 hours, the element is capable of striking internal organs. Two weeks after intoxication, traces of arsenic can be found in nails and even in bones.

Symptoms of arsenic poisoning

Signs of the disease may vary depending on the dose taken.

• Acute form

Characterized by a persistent metallic taste in the mouth. A person feels a strong burning sensation in the throat, accompanied by spasms. The skin on the body takes on a bluish tint, and the palms turn yellow.

Blood pressure drops sharply, accompanied by powerful attacks of dizziness. In addition, the poisoned person experiences acute kidney and liver failure.

The patient also experiences diarrhea and severe stomach pain. Diarrhea is characterized by an acute form, as a result of which the body becomes dehydrated very quickly. In extreme cases, there is a high likelihood of pulmonary edema, paralysis or coma.

• Subacute form

There is an extremely acute headache. All mucous membranes, especially the eyes and Airways. This leads to a runny nose, nasal congestion and watery eyes.

The victim often sneezes and coughs. Severe nausea and even vomiting are also possible. After the spasms, an aftertaste with a metallic tint remains in the mouth.

• Chronic form

Fatigue and general malaise of the body sets in. The limbs become weak due to the anemic state. Peripheral sensitivity worsens up to complete loss. The skin gets goosebumps and feels numb.

Asterisks from blood vessels appear on the body and persistent rosacea develops.

In the absence of appropriate treatment, serious consequences are very likely, up to and including. Since arsenic is highly carcinogenic, poisoning can lead to the development of cancer in the body.

For a person who ingests arsenic trioxide, the lethal dose will range from 50 to 340 milligrams. It is tied to the type of substance and is directly related to a person’s weight and general condition health.

First aid for poisoning

If you or one of your loved ones or colleagues are accidentally poisoned by arsenic, you should provide immediate assistance before specialists arrive.

Actions are carried out according to simple algorithm:

• The first thing to do is to immediately call an ambulance;
• Before doctors arrive, give the victim an emetic to rinse the stomach;
• The next step is to take an absorbent (for example, milk with whipped protein or activated carbon);
• Place a hot heating pad on the victim’s stomach;
• If possible, prepare a special solution consisting of one spoon of burnt magnesia per 200 ml of water;
• Under no circumstances should the victim be allowed to smell ammonia or sour drink;
• If convulsions occur, rub the victim's limbs.

As is a strong poison that can cause great harm.

Unitol became the main antidote for arsenic. This is an effective antidote that has the property of binding it into safe compounds and allowing you to get rid of the chemical element with urea.

Timely preventive measures also help to remove the toxicological effect of arsenic when working in production.

How to prevent poisoning

To prevent poisoning, try to avoid products containing it. At workplaces, production processes are being sealed and ventilation is being improved.

Personal hygiene plays a huge role in the prevention of poisoning. A respirator must be used in the workplace. Or use cotton wool tampons that are placed in the ears and nostrils. After work, you should definitely wash yourself. In addition, take care of your overalls. Keep it clean and washed.

Regular medical examination should be a mandatory preventive measure. It is recommended to undergo such examinations at least twelve months with constant contact with drugs containing arsenic.

Some who died from cholera in the Middle Ages did not die from it. Symptoms of the disease are similar to those arsenic poisoning.

Having realized this, medieval businessmen began to offer the trioxide of the element as a poison. Substance. The lethal dose is only 60 grams.

They were divided into portions, given over several weeks. As a result, no one suspected that the man did not die from cholera.

The taste of arsenic is not felt in small doses, such as in food or drinks. IN modern realities Of course, there is no cholera.

People don't have to worry about arsenic. Rather, it is the mice who need to be afraid. A toxic substance is a type of poison for rodents.

By the way, the element is named in their honor. The word “arsenic” exists only in Russian-speaking countries. Official name substances – arsenicum.

Designation in – As. The serial number is 33. Based on it, we can assume full list properties of arsenic. But let's not assume. We'll look into the issue for sure.

Properties of arsenic

Latin name element is translated as “strong”. Apparently, this refers to the effect of the substance on the body.

When intoxicated, vomiting begins, digestion is upset, the stomach turns, and the functioning of the nervous system is partially blocked. not one of the weak ones.

Poisoning occurs from any of allotropic forms substances. Alltropy is the existence of manifestations of the same thing that are different in structure and properties. element. Arsenic most stable in metal form.

Steel-gray rhombohedral ones are fragile. The units have a characteristic metallic appearance, but upon contact with moist air they become dull.

Arsenic - metal, whose density is almost 6 grams per cubic centimeter. The remaining forms of the element have a lower indicator.

In second place is amorphous arsenic. Element characteristics: - almost black color.

The density of this form is 4.7 grams per cubic centimeter. Externally, the material resembles.

The usual state of arsenic for ordinary people is yellow. Cubic crystallization is unstable and becomes amorphous when heated to 280 degrees Celsius, or under the influence of simple light.

Therefore, yellow ones are soft, like in the dark. Despite the color, the aggregates are transparent.

From a number of modifications of the element it is clear that it is only half a metal. The obvious answer to the question is: “ Arsenic is a metal or non-metal", No.

Chemical reactions serve as confirmation. The 33rd element is acid-forming. However, being in acid itself does not give.

Metals do things differently. In the case of arsenic, they do not work out even upon contact with one of the strongest.

Salt-like compounds are “born” during the reactions of arsenic with active metals.

This refers to oxidizing agents. The 33rd substance interacts only with them. If the partner does not have expressed oxidative properties, the interaction will not take place.

This even applies to alkalis. That is, arsenic is a chemical element quite inert. How then can you get it if the list of reactions is very limited?

Arsenic mining

Arsenic is mined as a by-product of other metals. They are separated, leaving the 33rd substance.

In nature there are compounds of arsenic with other elements. It is from them that the 33rd metal is extracted.

The process is profitable, because together with arsenic there are often , , and .

It is found in granular masses or cubic crystals of tin color. Sometimes there is a yellow tint.

Arsenic compound And metal Ferrum has a “brother”, in which instead of the 33rd substance there is . This is an ordinary pyrite with a golden color.

The aggregates are similar to the arsenic version, but cannot serve as arsenic ore, although they also contain arsenic as an impurity.

By the way, arsenic also occurs in ordinary water, but, again, as an impurity.

The amount of element per ton is so small, but even by-product mining makes no sense.

If the world's arsenic reserves were evenly distributed in the earth's crust, it would be only 5 grams per ton.

So, the element is not common; its quantity is comparable to , , .

If you look at the metals with which arsenic forms minerals, then this is not only with cobalt and nickel.

Total number minerals of the 33rd element reaches 200. A native form of the substance is also found.

Its presence is explained by the chemical inertness of arsenic. Forming next to elements with which reactions are not provided, the hero remains in splendid isolation.

In this case, needle-shaped or cubic aggregates are often obtained. Usually, they grow together.

Use of arsenic

The element arsenic belongs to dual, not only exhibiting properties of both metal and non-metal.

The perception of the element by humanity is also dual. In Europe, the 33rd substance has always been considered a poison.

In 1733, they even issued a decree prohibiting the sale and purchase of arsenic.

In Asia, the “poison” has been used by doctors for 2000 years in the treatment of psoriasis and syphilis.

Modern doctors have proven that the 33rd element attacks proteins that provoke oncology.

In the 20th century, some European doctors also sided with the Asians. In 1906, for example, Western pharmacists invented the drug salvarsan.

It became the first in official medicine and was used against a number of infectious diseases.

True, immunity to the drug, like any constant intake of arsenic in small doses, is developed.

1-2 courses of the drug are effective. If immunity has developed, people can take a lethal dose of the element and remain alive.

In addition to doctors, metallurgists became interested in the 33rd element and began adding it to produce shot.

It is made on the basis which is included in heavy metals. Arsenic increases the lead and allows its splashes to take a spherical shape when casting. It is correct, which improves the quality of the fraction.

Arsenic can also be found in thermometers, or rather in them. It is called Viennese, mixed with the oxide of the 33rd substance.

The compound serves as a clarifier. Arsenic was also used by glassblowers of antiquity, but as a matting additive.

Glass becomes opaque when there is a significant admixture of a toxic element.

Observing the proportions, many glassblowers fell ill and died prematurely.

And tannery specialists use sulfides arsenic.

Element main subgroups Group 5 of the periodic table is included in some paints. In the leather industry, arsenicum helps remove hair from.

Arsenic price

Pure arsenic is most often offered in metallic form. Prices are set per kilogram or ton.

1000 grams costs about 70 rubles. For metallurgists, they offer ready-made, for example, arsenic and copper.

In this case, they charge 1500-1900 rubles per kilo. Arsenic anhydrite is also sold in kilograms.

It is used as a skin medicine. The agent is necrotic, that is, it numbs the affected area, killing not only the causative agent of the disease, but also the cells themselves. The method is radical, but effective.

Everyone has long known that arsenic can be both a medicine and a poison. But, despite its toxic properties, arsenic is very necessary for our body, because it prevents the loss of phosphorus. Phosphorus-calcium metabolism is regulated by vitamin D, and phosphorus metabolism is regulated by arsenic.

If there is not enough arsenic in the body, some forms of allergies may occur.

If a person has anemia and no appetite, then in some cases arsenic is used to eliminate such symptoms. In case of poisoning with a large dose of selenium, arsenic plays the role of a good antidote. When experiments were carried out on mice, it was found that using certain doses of arsenic can reduce the incidence of cancer.

However, as the concentration of arsenic in food or soil increases, the number of deaths caused by cancer of the eyes, larynx, and leukemia increases. This happens because the dose is close to toxic.

In the body, arsenic is found in hair and nails, approximately 15 - 20 mg.

Arsenic in food.

Arsenic is found in most plant and animal products, except refined sugar. Therefore, there is no need to take special care of this trace element. The amount of arsenic that is present in plants is usually sufficient for the body. But it is very important to know that you should not overuse seafood products such as shrimp, lobsters, lobsters and others, otherwise you can get increased amount poison.

Some types sea ​​fish and edible shellfish are considered the richest natural source arsenic.

Arsenic as a trace element enters the human body through drinking water, mineral water, juices, wines, seafood, pesticides, herbicides, medications. Arsenic is mainly deposited in the reticuloendothelial system. The optimal rate of arsenic intake into the body is considered to be 50-100 mcg/day. If the body receives 1 mcg or less of arsenic per day, a deficiency of the element may develop; the toxicity threshold is 20 mg per day.

IN fish oil contained greatest number arsenic - up to approximately 10 mg/kg, in wine - up to 1 mg/l. Drinking water includes arsenic slightly less than 10 µg/l. However, in countries such as India, Bangladesh, Mexico, Taiwan, arsenic in water is present in higher doses - more than 1 mg/l. As a result, massive chronic arsenic poisoning can often occur, and the so-called “black foot” disease develops.

IN gastrointestinal tract In humans, about 80% of arsenic is absorbed, 10% enters through the lungs and about 1% through the skin. 30% of arsenic is excreted from the body in the urine one day after its intake, approximately 4% in feces. Arsenic in the body accumulates in the skin, lungs, liver, small intestine. Normally, the human body should contain about 15 mg of this element. Arsenic is an immunotoxic, conditionally essential element. Arsenic interacts with thiol groups of proteins, glutathione, cysteine, and lipoic acid. Arsenic takes part in many important biochemical processes, for example, oxidative processes in mitochondria.

Excess arsenic in the body and poisoning with it.

All arsenic compounds, like arsenic itself, are poisonous. If acute arsenic poisoning occurs, vomiting with diarrhea and central nervous system disorders begin. Since the symptoms of arsenic poisoning are similar to those of cholera, it has long been successful in using arsenic compounds as a lethal poison, the most common compound being arsenic trioxide.

There are areas where the content of arsenic in soil and water is quite high. In these regions, people experience endemic goiter; arsenic can accumulate in the thyroid gland.

The symptoms of arsenic poisoning are not difficult to recognize: a metallic taste appears in the mouth, vomiting begins, and severe abdominal pain. Then convulsions, paralysis appear, and death occurs. For arsenic poisoning, milk is the most widely available and well-known antidote; more precisely, casein is the protein in milk. It is casein, in combination with arsenic, that is capable of forming an insoluble compound that is not absorbed into the blood.

Arsenic poisoning can occur when drinking poisoned water and food, in industrial conditions - when inhaling various arsenic compounds, as well as when using certain medications. If there is an excess of arsenic in the body, then the bone marrow, digestive tract, kidneys, skin, and lungs become target organs. There is ample evidence that inorganic arsenic compounds are carcinogenic. Among workers who work in the production of pesticides, smelting alloys of this element with other metals, especially copper, gold mining is one of the most high levels mortality from lung cancer. Skin cancer (Bowen's cancer) can often occur with long-term consumption of water contaminated with arsenic, as well as with long-term use of medications. There is a version that hemangioendothelioma of the liver is also considered an arsene-dependent tumor. If acute arsenic poisoning occurs, the stomach must be rinsed; in case of kidney damage, hemodialysis is performed. Unithiol is used as an antidote. In addition, it is recommended to use the antagonistic properties of zinc, phosphorus, sulfur, and additionally inject vitamins A, C, E and various vitamins.

Use of arsenic.

Arsenic is widely used for the treatment of caries in dentistry. According to statistics, caries is one of the most common diseases in dentistry; it is almost impossible to find at least one person who has healthy teeth. Caries begins when the calcareous salts of the tooth enamel are destroyed, and then pathogenic microbes spread, penetrating through the weakened tooth into the inner soft part. This is how a “carious cavity” appears; if you visit a dentist in time, you can simply clean the carious cavity and fill it with filling material; in this case, the nerve will not have to be removed, which means the tooth will remain alive. If you do not consult a doctor in time, the carious cavity will reach the pulp - this is tissue containing nerves, lymphatic and blood vessels, it becomes inflamed and the nerve is removed. A grain of arsenic is placed on the exposed pulp. Inflammation begins, and then the doctors, in order to avoid the worst, decide to kill the nerve; its acid kills the pulp within two days, after which the tooth is dead.

Arsenic is a classic poison of medieval and modern poisoners
and medicine in modern sports and rehabilitation medicine
Toxic and poisonous stones and minerals

Arsenic(lat. Arsenicum), As, chemical element of group V of the periodic system of Mendeleev, atomic number 33, atomic mass 74.9216; steel-gray crystals. The element consists of one stable isotope 75 As. Poisonous in any form, medicine.

Historical reference.

Natural compounds of arsenic with sulfur (orpiment As 2 S 3, realgar As 4 S 4) were known to the people ancient world who used these minerals as medicines and paints. The product of burning arsenic sulfides was also known - arsenic (III) oxide As 2 O 3 (“white arsenic”).

The name arsenikon is found already at the beginning of our era; it is derived from the Greek arsen - strong, courageous and served to designate arsenic compounds (based on their effect on the body). The Russian name is believed to come from “mysh” (“death” - after the use of arsenic preparations to kill yaks, as well as exterminate mice and rats). Chemical preparation free arsenic is attributed to 1250 AD. In 1789, A. Lavoisier included arsenic in the list of chemical elements.

Arsenic. Belorechenskoye deposit, North. Caucasus, Russia. ~10x7 cm. Photo: A.A. Evseev.

Distribution of arsenic in nature.

The average arsenic content in the earth's crust (clarke) is 1.7 * 10 -4% (by mass), in such quantities it is present in most igneous rocks. Since arsenic compounds are volatile when high temperatures(dry volcanic sublimation on batholiths), the element sublimes into the atmosphere and air in the form of metal vapors (mirages - the air below ripples) does not accumulate during magmatic lava processes sublimating through cracks and tubes; it concentrates, precipitating from vapors and hot deep waters on crystal formation catalysts - metallic iron (together with S, Se, Sb, Fe, Co, Ni, Cu and other elements).

During volcanic eruptions (during dry sublimation of arsenic), arsenic in the form of its volatile compounds enters the atmosphere. Since arsenic is multivalent, its migration is influenced by the redox environment. Under oxidizing conditions earth's surface arsenates (As 5+) and arsenites (As 3+) are formed.

These are rare minerals found in areas of arsenic deposits. Native arsenic and As 2+ minerals are even less common. Of the minerals and arsenic compounds (about 180), arsenopyrite FeAsS is of industrial importance (the iron atom is the center of pyrite formation, the formula of the starting “single crystal” is Fe + (As + S)).

Arsenopyrite vein. Trifonovskaya mine, Kochkarskoye deposit (Au), Plast, South Ural, Russia. Arsenics. Photo: A.A. Evseev.

Small amounts of arsenic are essential for life. However, in areas of arsenic deposits and the activity of young volcanoes, soils in some places contain up to 1% arsenic, which is associated with livestock diseases and death of vegetation. The accumulation of arsenic is especially typical for landscapes of steppes and deserts, in the soils of which arsenic is inactive. In humid climates and when plants and soils are watered, arsenic is washed out of the soil.

In living matter there is an average of 3·10 -5% arsenic, in rivers 3·10 -7%. Arsenic carried by rivers into the ocean precipitates relatively quickly. In sea water there is 1 * 10 -7% arsenic (there is a lot of gold there, which displaces it), but in clays and shales there is arsenic (along the banks of rivers and reservoirs, in clayey black formations and along the edges of quarries) - 6.6 * 10 - 4 %. Sedimentary iron ores, ferromanganese and other iron nodules are often enriched in arsenic.

Physical properties of arsenic.

Arsenic has several allotropic modifications. Under normal conditions, the most stable is the so-called metallic, or gray, arsenic (α-As) - steel gray fragile crystalline mass (according to properties - like pyrite, gold blende, iron pyrite); when freshly fractured, it has a metallic luster; in air it quickly becomes dull, as it is covered with a thin film of As 2 O 3 .

Arsenic is rarely called silver blende - the case of the Tsar's Clerks A.M. Romanov in the middle of the 17th century, “silver”, not malleable, comes in powder, can be ground - poison for the Tsar of All Rus'. The most famous Spanish scandal in the poisoners' tavern near the Don Quixote mill on the road to Almaden, Spain, where European continent red cinnabar is mined (scandals about the sale of virgins Krasnodar Territory RF, pos. New, crystalline red cinnabar, do not want to work).

Arsenopyrite. Druze of prismatic crystals with calcite spherulites. Freiberg, Saxony, Germany. Photo: A.A. Evseev.

The crystal lattice of gray arsenic is rhombohedral (a = 4.123Å, angle α = 54 o 10", x = 0.226), layered. Density 5.72 g/cm 3 (at 20 o C), specific electrical resistance 35*10 -8 ohm*m, or 35*10 -6 ohm*cm, temperature coefficient of electrical resistance 3.9·10 -3 (0 o -100 o C), Brinell hardness 1470 MN/m 2, or 147 kgf /mm 2 (3-4 according to Moocy); Arsenic is diamagnetic.

Under atmospheric pressure arsenic sublimes at 615 o C without melting, since triple pointα-As lies at 816 o C and a pressure of 36 at.

Arsenic vapor consists of As 4 molecules up to 800 o C, above 1700 o C - only As 2. When arsenic vapor condenses on a surface cooled by liquid air, yellow arsenic is formed - transparent, wax-soft crystals with a density of 1.97 g/cm 3, similar in properties to white phosphorus.

When exposed to light or low heat, it turns into gray arsenic. Glassy-amorphous modifications are known: black arsenic and brown arsenic, which, when heated above 270 o C, turn into gray arsenic

Chemical properties of arsenic.

Configuration outer electrons arsenic atom 3d 10 4s 2 4p 3 . In compounds, arsenic has oxidation states +5, +3 and -3. Gray arsenic is less chemically active than phosphorus. When heated in air above 400 o C, arsenic burns, forming As 2 O 3.

Arsenic combines directly with halogens; under normal conditions, AsF 5 is a gas; AsF 3 , AsCl 3 , AsBr 3 - colorless volatile liquids; AsI 3 and As 2 I 4 are red crystals. When arsenic is heated with sulfur, sulfides are obtained: orange-red As 4 S 4 and lemon-yellow As 2 S 3.

Pale yellow silver sulfide As 2 S 5 ( arsenopyrite) is deposited by passing H 2 S into an ice-cooled solution of arsenic acid (or its salts) in fuming hydrochloric acid: 2H 3 AsO 4 + 5H 2 S = As 2 S 5 + 8H 2 O; At about 500 o C it decomposes into As 2 S 3 and sulfur.

All arsenic sulfides are insoluble in water and dilute acids. Strong oxidizing agents (mixtures of HNO 3 + HCl, HCl + KClO 3) convert them into a mixture of H 3 AsO 4 and H 2 SO 4.

As 2 S 3 sulfide easily dissolves in ammonium sulfides and polysulfides and alkali metals, forming salts of acids - thioarsenic H 3 AsS 3 and thioarsenic H 3 AsS 4 .

With oxygen, arsenic produces oxides: arsenic oxide (III) As 2 O 3 - arsenous anhydride and arsenic oxide (V) As 2 O 5 - arsenic anhydride. The first of them is formed by the action of oxygen on arsenic or its sulfides, for example 2As 2 S 3 + 9O 2 = 2As 2 O 3 + 6SO 2.

As 2 O 3 vapors condense into a colorless glassy mass, which becomes opaque over time due to the formation of small cubic crystals, density 3.865 g/cm 3 . The vapor density corresponds to the formula As 4 O 6; above 1800 o C the steam consists of As 2 O 3.

2.1 g of As 2 O 3 dissolves in 100 g of water (at 25 o C). Arsenic (III) oxide is an amphoteric compound, with a predominance acidic properties. Salts (arsenites) corresponding to orthoarsenic acids H 3 AsO 3 and metaarsenic HAsO 2 are known; the acids themselves have not been obtained. Only alkali metal and ammonium arsenites are soluble in water.

As 2 O 3 and arsenites are usually reducing agents (for example, As 2 O 3 + 2I 2 + 5H 2 O = 4HI + 2H 3 AsO 4), but can also be oxidizing agents (for example, As 2 O 3 + 3C = 2As + 3SO ).

Arsenic (V) oxide is prepared by heating arsenic acid H 3 AsO 4 (about 200 o C). It is colorless, at about 500 o C it decomposes into As 2 O 3 and O 2. Arsenic acid is obtained by the action of concentrated HNO 3 on As or As 2 O 3.

Arsenic acid salts (arsenates) are insoluble in water, with the exception of alkali metal and ammonium salts. Salts are known that correspond to the acids orthoarsenic H 3 AsO 4 , metaarsenic HAsO 3 and pyroarsenic H 4 As 2 O 7 ; the last two acids were not obtained in a free state. When alloyed with metals, arsenic mostly forms compounds (arsenides).

Obtaining arsenic.

Arsenic is produced industrially by heating arsenic pyrites:

FeAsS = FeS + As

or (less often) reduction of As 2 O 3 with coal. Both processes are carried out in retorts made of refractory clay connected to a receiver for condensing arsenic vapor.

Arsenic anhydride is obtained by oxidative roasting of arsenic ores or as a by-product of roasting polymetallic ores, which almost always contain arsenic. During oxidative roasting, As 2 O 3 vapors are formed, which condense in the collection chambers.

Crude As 2 O 3 is purified by sublimation at 500-600 o C. Purified As 2 O 3 is used for the production of arsenic and its preparations.

Use of arsenic.

Small additions of arsenic (0.2-1.0% by weight) are added to lead used for the production of gun shot (arsenic increases surface tension molten lead, due to which the shot takes on a shape close to spherical; arsenic slightly increases the hardness of lead). As a partial substitute for antimony, arsenic is included in some babbitt and printing alloys.

Pure arsenic is not poisonous, but all its compounds that are soluble in water or can go into solution under the influence of gastric juice, extremely poisonous; Arsenic hydrogen is especially dangerous. Of the arsenic compounds used in production, arsenic anhydride is the most toxic.

Almost all sulfide ores of non-ferrous metals, as well as iron (sulfur) pyrite, contain an admixture of arsenic. Therefore, during their oxidative roasting, along with sulfur dioxide SO 2, As 2 O 3 is always formed; most of it condenses in the smoke channels, but with no or low efficiency treatment facilities the exhaust gases of ore roasting furnaces carry away noticeable amounts of As 2 O 3 .

Pure arsenic, although not poisonous, is always covered with a coating of toxic As 2 O 3 when stored in air. In the absence of properly performed ventilation, etching of metals (iron, zinc) with industrial sulfuric or hydrochloric acids containing arsenic is extremely dangerous, since this produces arsenous hydrogen.

Arsenic in the body.

As a trace element, arsenic is ubiquitous in living nature. The average arsenic content in soils is 4*10 -4%, in plant ash - 3*10 -5%. The arsenic content in marine organisms is higher than in terrestrial organisms (in fish 0.6-4.7 mg per 1 kg of raw material, accumulates in the liver).

The largest amount of it (per 1 g of tissue) is found in the kidneys and liver (when eaten, it does not accumulate in the brain). A lot of arsenic is found in the lungs and spleen, skin and hair; relatively little - in the cerebrospinal fluid, brain (mainly in the pituitary gland), gonads and others.

In tissues, arsenic is found mainly protein fraction(“the stone of bodybuilders and athletes”), much less - in the acid-soluble and only a small part of it is found in the lipid fraction. It is used to treat progressive muscular dystrophy - it does not accumulate in the brain and bones (sports doping, treated for hostages and prisoners of concentration camps such as "Auschwitz" in Poland, EU, 1941-1944).

Arsenic is involved in redox reactions: oxidative breakdown of complex biological carbohydrates and sugars, fermentation, glycolysis, etc. Improves mental abilities (promotes the process of breaking down sugars in the brain). Arsenic compounds are used in biochemistry as specific enzyme inhibitors to study metabolic reactions. Promotes the breakdown of biological tissues (accelerates). It is actively used in dentistry and oncology - to eliminate rapidly growing and early aging cancer cells and tumors.

Mixture (hard sulfide alloy) of thallium, arsenic and lead: Hutchinsonite (Hutchinsonite)

The mineral formula is (Pb, Tl)S` Ag2S * 5 As2 S5 - complex sulfide and adsenide carbide salt. Rhombus. The crystals are prismatic to needle-shaped. Cleavage perfect according to (010). The aggregates are radial-needle-shaped, granular. Hardness 1.5-2. Specific gravity 4.6. Red. Diamond shine. In hydrothermal deposits with dolomite, with sulfides and arsenides of Zn, Fe, As and sulfoarsenides. The result of dry sulfuric and arsenic sublimation of magma through calderas and open volcanic vents, as well as dry sublimation through cracks in deep magmatic plutonites from the hot magma of the Earth. Contains silver. It is one of the ten very dangerous to human and animal health and carcinogenic stones and minerals that crystallize in modern conditions among the others rocks in the form of harmful, hazardous to health (if handled without permission) and deceptive ore beauty. In the photo - Hutchinsonite with orpiment.

Poisonous minerals. Hutchinsonite - named after the mineralogist Hutchinson from Cambridge University and resembles lead in appearance (it can be used for protection against radiation). Opened in 1861. A deadly mixture (hard alloy) of thallium, arsenic and lead. Contact with this mineral can lead to hair loss (alopecia, baldness, baldness), complex skin diseases and fatal outcome(of death). All of its main components are poisonous. Very similar to lead, native silver, pyrite ("dry pyrite") and arsenopyrite. It is also similar to stibnite (an antimony compound, also very poisonous). Also similar to zeolites. Hutchinsonite is a dangerous and striking carbide mixture of thallium, lead and arsenic. Three rare, very expensive and valuable ore metals form a toxic, lethal cocktail of minerals that must be handled with the utmost care. Affects the brain, heart and liver simultaneously.

Thallium is lead's dark counterpart. This dense, fatty metal is similar in atomic mass to lead, but is even more deadly. Thallium is a rare metal that appears in highly toxic compounds consisting of strange combinations of elements ( hard alloys). The effects of thallium exposure are more dangerous than lead, and include hair loss (alopecia, baldness), serious illness from skin contact, and in many cases death. Hutchinsonite was named after John Hutchinson, a famous mineralogist at the University of Cambridge. This mineral can be found in mountainous regions of Europe, most often in ore deposits. A mineral popular in medical dentistry, etc. Alcoholics are afraid of the mineral.

Hutchinsonite (Hutchinsonite) is sometimes jokingly called “dry” or “solid alcohol”, “solid alcohol” (and not only for the harmful effects of intoxicating poisoning on the body and human health). Chemical formula food grade alcohol(alcohol) - C2 H5 (OH). Hutchinsonite (Hutchinsonite) has a chemical formula - 5 As2 S5 * (Pb, Tl) S` Ag2 S or 5 As2 S5 * (Pb, Tl) S` Ag Ag S. The formula of Hutchinsonite (Hutchinsonite) is sometimes rewritten differently - As2 S5 * ( Pb) + As2 S5 * (Tl) + As2 S5 * S + As2 S5 * Ag + As2 S5 * AgS. Chemical separation of components in production is also carried out according to the type of different alcohols (layers of mechanical enrichment, different in mass and weight, which are crushed by ultrasound and separated in a centrifuge or on a vibration platform - the horror movie "Aliens"). Other similar options are possible chemical formula(composition varies).

ADR 6.1
Toxic substances (poison)
Risk of poisoning through inhalation, skin contact or ingestion. Hazardous to aquatic life environment or sewer system
Use a mask for emergency abandonment vehicle

ADR 3
Flammable liquids
Fire risk. Risk of explosion. Containers can explode when heated (extremely dangerous - burn easily)

ADR 2.1
Flammable gases
Fire risk. Risk of explosion. May be under pressure. Risk of suffocation. May cause burns and/or frostbite. Containers can explode when heated (extremely dangerous - practically do not burn)
Use cover. Avoid low surface areas (holes, lowlands, trenches)
Red diamond, ADR number, black or white flame

ADR 2.2
Gas cylinder Non-flammable, non-toxic gases.
Risk of suffocation. May be under pressure. They can cause frostbite (similar to a burn - pallor, blisters, black gas gangrene - creaking). Containers can explode when heated (extremely dangerous - explosion from a spark, flame, match, practically do not burn)
Use cover. Avoid low surface areas (holes, lowlands, trenches)
Green diamond, ADR number, black or white gas cylinder (cylinder, thermos type)

ADR 2.3
Toxic gases. Skull and crossbones
Danger of poisoning. May be under pressure. May cause burns and/or frostbite. Containers can explode when heated (extremely dangerous - instantaneous spread of gases throughout the surrounding area)
Use a mask when leaving a vehicle in an emergency. Use cover. Avoid low surface areas (holes, lowlands, trenches)
White diamond, ADR number, black skull and crossbones