Physical and chemical bases of the sulfur combustion process.

The combustion of S occurs with the release of a large amount of heat: 0.5S 2g + O 2g \u003d SO 2g, ΔH \u003d -362.43 kJ

Combustion is a complex of chemical and physical phenomena. In an incinerator, one has to deal with complex fields of velocities, concentrations, and temperatures that are difficult to describe mathematically.

The combustion of molten S depends on the conditions of interaction and combustion of individual droplets. The efficiency of the combustion process is determined by the time of complete combustion of each particle of sulfur. The combustion of sulfur, which occurs only in the gas phase, is preceded by the evaporation of S, the mixing of its vapors with air, and the heating of the mixture to t, which provides the necessary reaction rate. Since evaporation from the surface of the drop begins more intensively only at a certain t, each drop of liquid sulfur must be heated to this t. The higher t, the longer it takes to heat the drop. When a combustible mixture of vapors S and air of maximum concentration and t is formed above the surface of the drop, ignition occurs. The combustion process of a drop S depends on the combustion conditions: t and the relative velocity of the gas flow, and the physicochemical properties of liquid S (for example, the presence of solid ash impurities in S), and consists of the following stages: 1-mixing drops of liquid S with air; 2-heating of these drops and evaporation; 3-thermal vapor splitting S; 4-formation of the gas phase and its ignition; 5-combustion of the gas phase.

These stages occur almost simultaneously.

As a result of heating, a drop of liquid S begins to evaporate, vapors of S diffuse to the combustion zone, where at high t they begin to actively react with O 2 of the air, the process of diffusion combustion of S occurs with the formation of SO 2.

At high t, the rate of the oxidation reaction S is greater than the rate of physical processes, so the overall rate of the combustion process is determined by the processes of mass and heat transfer.

Molecular diffusion determines a calm, relatively slow combustion process, while turbulent diffusion accelerates it. As the droplet size decreases, the evaporation time decreases. Fine atomization of sulfur particles and their uniform distribution in the air flow increases the contact surface, facilitates heating and evaporation of the particles. During the combustion of each single drop S in the composition of the torch, 3 periods should be distinguished: I- incubation; II- intense burning; III- burnout period.

When a drop burns, flames erupt from its surface, resembling solar flares. In contrast to conventional diffusion combustion with the ejection of flames from the surface of a burning drop, it was called "explosive combustion".

The combustion of the S drop in the diffusion mode is carried out by the evaporation of molecules from the surface of the drop. The evaporation rate depends on the physical properties of the liquid and the t of the environment, and is determined by the characteristic of the evaporation rate. In differential mode, S lights up in periods I and III. Explosive combustion of a drop is observed only in the period of intense combustion in period II. The duration of the intense burning period is proportional to the cube of the initial droplet diameter. This is due to the fact that explosive combustion is a consequence of the processes occurring in the volume of the drop. Burning rate characteristic calc. by f-le: To= /τ sg;

d n is the initial droplet diameter, mm; τ is the time of complete combustion of the drop, s.

The characteristic of the burning rate of a drop is equal to the sum of the characteristics of diffusion and explosive combustion: To= K vz + K diff; kvz= 0.78∙exp(-(1.59∙p) 2.58); K diff= 1.21∙p +0.23; K T2\u003d K T1 ∙ exp (E a ​​/ R ∙ (1 / T 1 - 1 / T 2)); K T1 - burning rate constant at t 1 \u003d 1073 K. K T2 - const. heating rate at t different from t 1 . Еа is the activation energy (7850 kJ/mol).

THEN. The main conditions for efficient combustion of liquid S are: the supply of all the necessary amount of air to the mouth of the torch, fine and uniform atomization of liquid S, flow turbulence and high t.

The general dependence of the intensity of evaporation of liquid S on the gas velocity and t: K 1= a∙V/(b+V); a, b are constants depending on t. V - speed gas, m/s. At higher t, the dependence of the evaporation intensity S on the gas velocity is given by: K 1= K o ∙ V n ;

t, o C	lgK about	n
	4,975	0,58
	5,610	0,545
	6,332	0,8

With an increase in t from 120 to 180 o C, the intensity of evaporation of S increases by 5-10 times, and t 180 to 440 o C by 300-500 times.

The evaporation rate at a gas velocity of 0.104 m/s is determined by: = 8.745 - 2600/T (at 120-140 o C); = 7.346 -2025/T (at 140-200 o C); = 10.415 - 3480 / T (at 200-440 ° C).

To determine the evaporation rate S at any t from 140 to 440 ° C and a gas velocity in the range of 0.026-0.26 m / s, it is first found for a gas velocity of 0.104 m / s and recalculated to another speed: lg = lg + n ∙ lgV `` /V ` ; Comparison of the value of the evaporation rate of liquid sulfur and the combustion rate suggests that the combustion intensity cannot exceed the evaporation rate at the boiling point of sulfur. This confirms the correctness of the combustion mechanism, according to which sulfur burns only in the vapor state. The rate constant of sulfur vapor oxidation (the reaction proceeds according to the second-order equation) is determined by the kinetic equation: -dС S /d = К∙С S ∙С О2 ; C S is the vapor concentration S; C O2 - conc-I vapors O 2; K is the reaction rate constant. The total concentration of vapors S and O 2 op-yut: C S= a(1-x); With O2= b - 2ax; a is the initial vapor concentration S; b - initial concentration of O 2 vapors; х is the degree of vapor oxidation S. Then:

K∙τ= (2,3 /(b – 2a)) ∙ (lg(b – ax/b(1 - x)));

The rate constant of the oxidation reaction S to SO 2: lgK\u003d B - A / T;

about C	650 - 850	850 - 1100
AT	3,49	2,92
BUT

Drops of sulfur d< 100мкм сгорают в диффузионном режиме; d>100 µm in explosive, in the area of ​​100-160 µm, the burning time of drops does not increase.

That. to intensify the combustion process, it is advisable to spray sulfur into droplets d = 130-200 µm, which requires additional energy. When burning the same number of S received. SO 2 is the more concentrated, the smaller the volume of furnace gas and the higher its t.

1 - C O2; 2 - With SO2

The figure shows an approximate relationship between t and the SO 2 concentration in the furnace gas produced by the adiabatic combustion of sulfur in air. In practice, highly concentrated SO 2 is obtained, limited by the fact that at t > 1300, the lining of the furnace and gas ducts is quickly destroyed. In addition, under these conditions, side reactions between O 2 and N 2 of air can occur with the formation of nitrogen oxides, which is an undesirable impurity in SO 2, therefore, t = 1000-1200 is usually maintained in sulfur furnaces. And furnace gases contain 12-14 vol% SO 2 . From one volume of O 2 one volume of SO 2 is formed, therefore the maximum theoretical content of SO 2 in the combustion gas when burning S in air is 21%. When burning S in air, firing. O 2 The content of SO 2 in the gas mixture may increase depending on the concentration of O 2 . The theoretical content of SO 2 when burning S in pure O 2 can reach 100%. The possible composition of the roasting gas obtained by burning S in air and in various oxygen-nitrogen mixtures is shown in the figure:

Furnaces for burning sulfur.

Combustion of S in sulfuric acid production is carried out in furnaces in atomized or TV state. For burning the melted S, use nozzle, cyclone and vibration furnaces. The most widely used are cyclone and injector. These furnaces are classified according to the signs:- according to the type of installed nozzles (mechanical, pneumatic, hydraulic) and their location in the furnace (radial, tangential); - by the presence of screens inside the combustion chambers; - by execution (horizons, verticals); - according to the location of the inlet holes for air supply; - for devices for mixing air flows with S vapors; - for equipment for using the heat of combustion S; - by number of cameras.

Nozzle oven (rice)

1 - steel cylinder, 2 - lining. 3 - asbestos, 4 - partitions. 5 - nozzle for spraying fuel, 6 nozzles for spraying sulfur,

7 - a box for supplying air to the furnace.

It has a fairly simple design, easy to maintain, it has an image of gas, a constant concentration of SO 2. To serious shortcomings include: gradual destruction of partitions due to high t; low heat stress of the combustion chamber; difficulty in obtaining high concentration gas, tk. use a large excess of air; dependence of the percentage of combustion on the quality of spraying S; significant fuel consumption during start-up and heating of the furnace; comparatively large dimensions and weight, and as a result, significant capital investments, production areas, operating costs and large heat losses in the environment.

More perfect cyclone ovens.

1 - prechamber, 2 - air box, 3, 5 - afterburning chambers, 4. 6 pinch rings, 7, 9 - nozzles for air supply, 8, 10 - nozzles for sulfur supply.

Delivery: tangential air input and S; ensures uniform combustion of S in the furnace due to better flow turbulence; the possibility of obtaining the final process gas up to 18% SO 2; high thermal stress of the furnace space (4.6 10 6 W / m 3); the volume of the apparatus is reduced by a factor of 30-40 compared to the volume of a nozzle furnace of the same capacity; permanent concentration SO 2; simple regulation of the combustion process S and its automation; low time and combustible material for heating and starting the furnace after a long stop; lower content of nitrogen oxides after the furnace. Basic weeks associated with high t in the combustion process; possible cracking of the lining and welds; Unsatisfactory spraying of S leads to a breakthrough of its vapors in the t / exchange equipment after the furnace, and consequently to corrosion of the equipment and inconstancy of t at the inlet to the t / exchange equipment.

Molten S can enter the furnace through tangential or axial nozzles. With the axial location of the nozzles, the combustion zone is closer to the periphery. At tangent - closer to the center, due to which the effect of high t on the lining is reduced. (rice) The gas flow rate is 100-120m / s - this creates a favorable condition for mass and heat transfer, and the burning rate increases S.

Vibrating oven (rice).

1 – burner furnace head; 2 - return valves; 3 - vibration channel.

During vibrating combustion, all the parameters of the process periodically change (pressure in the chamber, speed and composition of the gas mixture, t). Device for vibrats. combustion S is called a furnace-burner. Before the furnace, S and air are mixed, and they flow through check valves (2) into the head of the furnace-burner, where the mixture is burned. The supply of raw materials is carried out in portions (processes are cyclic). In this version of the furnace, the heat output and burning rate increase significantly, but before igniting the mixture, a good mixing of the atomized S with air is necessary so that the process goes instantly. In this case, the combustion products mix well, the SO 2 gas film surrounding the S particles is destroyed and facilitates the access of new portions of O 2 in the combustion zone. In such a furnace, the resulting SO 2 does not contain unburned particles, its concentration is high at the top.

For a cyclone furnace, in comparison with a nozzle furnace, it is characterized by 40-65 times greater thermal stress, the possibility of obtaining more concentrated gas and greater steam production.

The most important equipment for furnaces for burning liquid S is the nozzle, which must ensure a thin and uniform spray of liquid S, good mixing of it with air in the nozzle itself and behind it, quick adjustment of the flow rate of liquid S while maintaining the necessary its ratio with air, the stability of a certain shape, the length of the torch, and also have a solid design, reliable and easy to use. For the smooth operation of the nozzles, it is important that the S is well cleaned of ash and bitumen. Nozzles are mechanical (yield under its own pressure) and pneumatic (air is still involved in spraying) action.

Utilization of the heat of combustion of sulfur.

The reaction is highly exothermic, as a result, a large amount of heat is released and the gas temperature at the outlet of the furnaces is 1100-1300 0 C. For contact oxidation of SO 2, the gas temperature at the inlet to the 1st layer of the cat-ra should not exceed 420 - 450 0 C. Therefore, before the SO 2 oxidation stage, it is necessary to cool the gas flow and utilize excess heat. In sulfuric acid systems operating on sulfur for heat recovery, water-tube heat recovery boilers with natural heat circulation are most widely used. SETA - C (25 - 24); RKS 95 / 4.0 - 440.

Energy-technological boiler RKS 95/4.0 - 440 is a water-tube, natural circulation, gas-tight boiler, designed to work with pressurization. The boiler consists of 1st and 2nd stage evaporators, stage 1.2 remote economizers, stage 1.2 remote superheaters, drum, sulfur combustion furnaces. The furnace is designed for burning up to 650 tons of liquid. Sulfur per day. The furnace consists of two cyclones connected relative to each other at an angle of 110 0 and a transition chamber.

Inner body with a diameter of 2.6 m, rests freely on supports. The outer casing is 3 m in diameter. The annular space formed by the inner and outer casings is filled with air, which then enters the combustion chamber through nozzles. Sulfur is supplied to the furnace by 8 sulfur nozzles, 4 on each cyclone. Sulfur combustion occurs in a swirling gas-air flow. The swirling of the flow is achieved by tangentially introducing air into the combustion cyclone through air nozzles, 3 in each cyclone. The amount of air is controlled by motorized flaps on each air nozzle. The transition chamber is designed to direct the gas flow from the horizontal cyclones to the vertical gas duct of the evaporator. The inner surface of the firebox is lined with mulite-corundum brick of the MKS-72 brand, 250 mm thick.

1 - cyclones

2 - transition chamber

3 - evaporation devices

When receiving roasting gas by burning sulfur, there is no need to clean it from impurities. The preparation stage will only include gas drying and acid disposal. When sulfur is burned, an irreversible exothermic reaction occurs:

S + O 2 = SO 2 (1)

with the release of a very large amount of heat: a change in H \u003d -362.4 kJ / mol, or in terms of a unit of mass 362.4 / 32 \u003d 11.325 kJ / t \u003d 11325 kJ / kg S.

Molten liquid sulfur supplied for combustion evaporates (boils) at a temperature of 444.6 *C; the heat of vaporization is 288 kJ/kg. As can be seen from the above data, the heat of the combustion reaction of sulfur is quite sufficient to evaporate the feedstock, so the interaction of sulfur and oxygen occurs in the gas phase (homogeneous reaction).

The combustion of sulfur in industry is carried out as follows. Sulfur is pre-melted (for this you can use water vapor obtained by utilizing the heat of the main combustion reaction of sulfur). Since the melting point of sulfur is relatively low, it is easy to separate mechanical impurities that have not passed into the liquid phase by settling and subsequent filtration from sulfur, and to obtain a feedstock of a sufficient degree of purity. Two types of furnaces are used to burn molten sulfur - nozzle and cyclone. It is necessary to provide for the spraying of liquid sulfur in them for its rapid evaporation and ensuring reliable contact with air in all parts of the apparatus.

From the kiln, the roasting gas enters the waste heat boiler and then to the subsequent apparatuses.

The concentration of sulfur dioxide in the roasting gas depends on the ratio of sulfur and air supplied for combustion. If air is taken in a stoichiometric amount, i.e. for every mole of sulfur 1 mole of oxygen, then with complete combustion of sulfur, the concentration will be equal to the volume fraction of oxygen in the air C so 2. max \u003d 21%. However, air is usually taken in excess, otherwise the furnace temperature will be too high.

With adiabatic combustion of sulfur, the firing temperature for the reaction mixture of stoichiometric composition will be ~ 1500*C. In practical terms, the possibility of increasing the temperature in the furnace is limited by the fact that above 1300*C the lining of the furnace and gas ducts is quickly destroyed. Usually, when burning sulfur, a roasting gas containing 13 - 14% SO 2 is obtained.

2. Contact oxidation of so2 to so3

Contact oxidation of sulfur dioxide is a typical example of heterogeneous oxidative exothermic catalysis.

This is one of the most studied catalytic syntheses. In the USSR, the most thorough work on the study of the oxidation of SO 2 to SO 3 and the development of catalysts was carried out by G.K. Boreskov. Sulfur dioxide oxidation reaction

SO 2 + 0,5 O 2 = SO 3 (2)

is characterized by a very high value of activation energy and therefore its practical implementation is possible only in the presence of a catalyst.

In industry, the main catalyst for the oxidation of SO 2 is a catalyst based on vanadium oxide V 2 O 5 (vanadium contact mass). Catalytic activity in this reaction is also shown by other compounds, primarily platinum. However, platinum catalysts are extremely sensitive even to traces of arsenic, selenium, chlorine and other impurities, and therefore were gradually replaced by vanadium catalysts.

The reaction rate increases with an increase in oxygen concentration, so the process in industry is carried out with an excess of it.

Since the SO 2 oxidation reaction belongs to the exothermic type, the temperature regime for its implementation should approach the line of optimal temperatures. The choice of temperature mode is additionally imposed by two restrictions associated with the properties of the catalyst. The lower temperature limit is the ignition temperature of vanadium catalysts, which, depending on the specific type of catalyst and gas composition, is 400 - 440 * C. the upper temperature limit is 600 - 650*C and is determined by the fact that above these temperatures the catalyst structure is rearranged and it loses its activity.

In the range of 400 - 600 * C, the process is sought to be carried out in such a way that as the degree of conversion increases, the temperature decreases.

Most often in industry, shelf contact devices with external heat exchange are used. The heat exchange scheme assumes the maximum use of the heat of reaction for heating the source gas and simultaneous cooling of the gas between the shelves.

One of the most important tasks facing the sulfuric acid industry is to increase the degree of conversion of sulfur dioxide and reduce its emissions into the atmosphere. This problem can be solved in several ways.

One of the most rational methods for solving this problem, which is widely used in the sulfuric acid industry, is the double contact and double absorption method (DKDA). To shift the equilibrium to the right and increase the yield of the process, as well as to increase the speed of the process, the process is carried out according to this method. Its essence lies in the fact that the reaction mixture, in which the degree of conversion of SO 2 is 90 - 95%, is cooled and sent to an intermediate absorber to separate SO 3 . In the remaining reaction gas, the ratio of O 2 :SO 2 increases significantly, which leads to a shift of the reaction equilibrium to the right. The newly heated reaction gas is again fed into the contact apparatus, where 95% of the conversion of the remaining SO 2 is reached on one or two catalyst layers. The total conversion of SO 2 in this process is 99.5% - 99.8%.

Sulfur is a chemical element that is in the sixth group and third period of the periodic table. In this article, we will take a detailed look at its chemical and production, use, and so on. The physical characteristic includes such features as color, electrical conductivity level, sulfur boiling point, etc. The chemical one describes its interaction with other substances.

Sulfur in terms of physics

This is a fragile substance. Under normal conditions, it is in a solid state of aggregation. Sulfur has a lemon yellow color.

And for the most part, all its compounds have yellow tints. Does not dissolve in water. It has low thermal and electrical conductivity. These features characterize it as a typical non-metal. Despite the fact that the chemical composition of sulfur is not at all complicated, this substance can have several variations. It all depends on the structure of the crystal lattice, with the help of which atoms are connected, but they do not form molecules.

So, the first option is rhombic sulfur. She is the most stable. The boiling point of this type of sulfur is four hundred and forty-five degrees Celsius. But in order for a given substance to pass into a gaseous state of aggregation, it must first pass through a liquid state. So, the melting of sulfur occurs at a temperature that is one hundred and thirteen degrees Celsius.

The second option is monoclinic sulfur. It is a needle-shaped crystals with a dark yellow color. The melting of sulfur of the first type, and then its slow cooling leads to the formation of this type. This variety has almost the same physical characteristics. For example, the boiling point of sulfur of this type is still the same four hundred and forty-five degrees. In addition, there is such a variety of this substance as plastic. It is obtained by pouring into cold water heated almost to a boil rhombic. The boiling point of sulfur of this type is the same. But the substance has the property of stretching like rubber.

Another component of the physical characteristic that I would like to talk about is the ignition temperature of sulfur.

This indicator may vary depending on the type of material and its origin. For example, the ignition temperature of technical sulfur is one hundred and ninety degrees. This is a rather low figure. In other cases, the flash point of sulfur can be two hundred and forty-eight degrees and even two hundred and fifty-six. It all depends on what material it was mined from, what density it has. But we can conclude that the combustion temperature of sulfur is quite low, compared with other chemical elements, it is a flammable substance. In addition, sometimes sulfur can combine into molecules consisting of eight, six, four or two atoms. Now, having considered sulfur from the point of view of physics, let's move on to the next section.

Chemical characterization of sulfur

This element has a relatively low atomic mass, it is equal to thirty-two grams per mole. The characteristic of the sulfur element includes such a feature of this substance as the ability to have different degrees of oxidation. In this it differs from, say, hydrogen or oxygen. Considering the question of what is the chemical characteristic of the sulfur element, it is impossible not to mention that, depending on the conditions, it exhibits both reducing and oxidizing properties. So, in order, consider the interaction of a given substance with various chemical compounds.

Sulfur and simple substances

Simple substances are substances that contain only one chemical element. Its atoms may combine into molecules, as, for example, in the case of oxygen, or they may not combine, as is the case with metals. So, sulfur can react with metals, other non-metals and halogens.

Interaction with metals

A high temperature is required to carry out this kind of process. Under these conditions, an addition reaction occurs. That is, metal atoms combine with sulfur atoms, thus forming complex substances sulfides. For example, if you heat two moles of potassium by mixing them with one mole of sulfur, you get one mole of the sulfide of this metal. The equation can be written in the following form: 2K + S = K 2 S.

Reaction with oxygen

This is sulfur burning. As a result of this process, its oxide is formed. The latter can be of two types. Therefore, the combustion of sulfur can occur in two stages. The first is when one mole of sulfur and one mole of oxygen form one mole of sulfur dioxide. You can write the equation for this chemical reaction as follows: S + O 2 \u003d SO 2. The second stage is the addition of one more oxygen atom to the dioxide. This happens if you add one mole of oxygen to two moles at high temperature. The result is two moles of sulfur trioxide. The equation for this chemical interaction looks like this: 2SO 2 + O 2 = 2SO 3. As a result of this reaction, sulfuric acid is formed. So, by carrying out the two processes described, it is possible to pass the resulting trioxide through a jet of water vapor. And we get The equation for such a reaction is written as follows: SO 3 + H 2 O \u003d H 2 SO 4.

Interaction with halogens

Chemical like other non-metals, allow it to react with this group of substances. It includes compounds such as fluorine, bromine, chlorine, iodine. Sulfur reacts with any of them, except for the last one. As an example, we can cite the process of fluorination of the element of the periodic table we are considering. By heating the mentioned non-metal with a halogen, two variations of fluoride can be obtained. The first case: if we take one mole of sulfur and three moles of fluorine, we get one mole of fluoride, the formula of which is SF 6. The equation looks like this: S + 3F 2 = SF 6. In addition, there is a second option: if we take one mole of sulfur and two moles of fluorine, we get one mole of fluoride with the chemical formula SF 4 . The equation is written in the following form: S + 2F 2 = SF 4 . As you can see, it all depends on the proportions in which the components are mixed. In exactly the same way, it is possible to carry out the process of chlorination of sulfur (two different substances can also be formed) or bromination.

Interaction with other simple substances

The characterization of the element sulfur does not end there. The substance can also enter into a chemical reaction with hydrogen, phosphorus and carbon. Due to the interaction with hydrogen, sulfide acid is formed. As a result of its reaction with metals, their sulfides can be obtained, which, in turn, are also obtained by direct reaction of sulfur with the same metal. The addition of hydrogen atoms to sulfur atoms occurs only under conditions of very high temperature. When sulfur reacts with phosphorus, its phosphide is formed. It has the following formula: P 2 S 3. In order to get one mole of this substance, you need to take two moles of phosphorus and three moles of sulfur. When sulfur interacts with carbon, the carbide of the considered non-metal is formed. Its chemical formula looks like this: CS 2. In order to get one mole of this substance, you need to take one mole of carbon and two moles of sulfur. All the addition reactions described above occur only when the reactants are heated to high temperatures. We have considered the interaction of sulfur with simple substances, now let's move on to the next point.

Sulfur and complex compounds

Compounds are those substances whose molecules consist of two (or more) different elements. The chemical properties of sulfur allow it to react with compounds such as alkalis, as well as concentrated sulphate acid. Its reactions with these substances are rather peculiar. First, consider what happens when the non-metal in question is mixed with alkali. For example, if we take six moles and add three moles of sulfur to them, we get two moles of potassium sulfide, one mole of this metal sulfite and three moles of water. This kind of reaction can be expressed by the following equation: 6KOH + 3S \u003d 2K 2 S + K2SO 3 + 3H 2 O. The interaction occurs according to the same principle if you add Next, consider the behavior of sulfur when a concentrated solution of sulfate acid is added to it. If we take one mole of the first and two moles of the second substance, we get the following products: sulfur trioxide in the amount of three moles, and also water - two moles. This chemical reaction can only take place when the reactants are heated to a high temperature.

Obtaining the considered non-metal

There are several main methods by which sulfur can be extracted from a variety of substances. The first method is to isolate it from pyrite. The chemical formula of the latter is FeS 2 . When this substance is heated to a high temperature without access to oxygen, another iron sulfide - FeS - and sulfur can be obtained. The reaction equation is written as follows: FeS 2 \u003d FeS + S. The second method of obtaining sulfur, which is often used in industry, is the combustion of sulfur sulfide under the condition of a small amount of oxygen. In this case, you can get the considered non-metal and water. To carry out the reaction, you need to take the components in a molar ratio of two to one. As a result, we get the final products in proportions of two to two. The equation for this chemical reaction can be written as follows: 2H 2 S + O 2 \u003d 2S + 2H 2 O. In addition, sulfur can be obtained during various metallurgical processes, for example, in the production of metals such as nickel, copper and others.

Industrial use

The non-metal we are considering has found its widest application in the chemical industry. As mentioned above, here it is used to obtain sulfate acid from it. In addition, sulfur is used as a component for the manufacture of matches, due to the fact that it is a flammable material. It is also indispensable in the production of explosives, gunpowder, sparklers, etc. In addition, sulfur is used as one of the ingredients in pest control products. In medicine, it is used as a component in the manufacture of drugs for skin diseases. Also, the substance in question is used in the production of various dyes. In addition, it is used in the manufacture of phosphors.

Electronic structure of sulfur

As you know, all atoms consist of a nucleus, in which there are protons - positively charged particles - and neutrons, i.e. particles that have a zero charge. Electrons revolve around the nucleus with a negative charge. For an atom to be neutral, it must have the same number of protons and electrons in its structure. If there are more of the latter, this is already a negative ion - an anion. If, on the contrary, the number of protons is greater than the number of electrons, this is a positive ion, or cation. The sulfur anion can act as an acid residue. It is part of the molecules of substances such as sulfide acid (hydrogen sulfide) and metal sulfides. An anion is formed during electrolytic dissociation, which occurs when a substance is dissolved in water. In this case, the molecule decomposes into a cation, which can be represented as a metal or hydrogen ion, as well as a cation - an ion of an acid residue or a hydroxyl group (OH-).

Since the serial number of sulfur in the periodic table is sixteen, we can conclude that exactly this number of protons is in its nucleus. Based on this, we can say that there are also sixteen electrons rotating around. The number of neutrons can be found by subtracting the serial number of the chemical element from the molar mass: 32 - 16 \u003d 16. Each electron does not rotate randomly, but along a certain orbit. Since sulfur is a chemical element that belongs to the third period of the periodic table, there are three orbits around the nucleus. The first one has two electrons, the second has eight, and the third has six. The electronic formula of the sulfur atom is written as follows: 1s2 2s2 2p6 3s2 3p4.

Prevalence in nature

Basically, the considered chemical element is found in the composition of minerals, which are sulfides of various metals. First of all, it is pyrite - iron salt; it is also lead, silver, copper luster, zinc blende, cinnabar - mercury sulfide. In addition, sulfur can also be included in the composition of minerals, the structure of which is represented by three or more chemical elements.

For example, chalcopyrite, mirabilite, kieserite, gypsum. You can consider each of them in more detail. Pyrite is a ferrum sulfide, or FeS 2 . It has a light yellow color with a golden sheen. This mineral can often be found as an impurity in lapis lazuli, which is widely used to make jewelry. This is due to the fact that these two minerals often have a common deposit. Copper shine - chalcocite, or chalcosine - is a bluish-gray substance, similar to metal. and silver luster (argentite) have similar properties: they both look like metals, have a gray color. Cinnabar is a brownish-red dull mineral with gray patches. Chalcopyrite, whose chemical formula is CuFeS 2 , is golden yellow, it is also called golden blende. Zinc blende (sphalerite) can have a color from amber to fiery orange. Mirabilite - Na 2 SO 4 x10H 2 O - transparent or white crystals. It is also called used in medicine. The chemical formula of kieserite is MgSO 4 xH 2 O. It looks like a white or colorless powder. The chemical formula of gypsum is CaSO 4 x2H 2 O. In addition, this chemical element is part of the cells of living organisms and is an important trace element.