Its application.

Slaked lime(formula – Ca(OH)2) is a strong base. May often be found in some sources under the name calcium hydroxide or "fluff".

Properties: It is presented as a white powder that is slightly soluble in water. The lower the temperature of the medium, the lower the solubility. The products of its reaction with acid are the corresponding calcium salts. For example, immersing slaked lime in sulfuric acid produces calcium sulfate and water. If you leave the fluff solution in the air, it will interact with one of the components of the latter - carbon dioxide. At this process the solution becomes cloudy. The products of this reaction are calcium carbonate and water. If you continue bubbling carbon dioxide, the reaction will end with the formation of calcium bicarbonate, which is destroyed as the temperature of the solution increases. Slaked lime and carbon monoxide will interact at a temperature of about 400°C, its products will be the already known carbonate and hydrogen. The substance can also react with salts, but only if the process ends with the formation of a precipitate, for example, if you mix “fluff” with sodium sulfite, the reaction products will be sodium hydroxide and calcium sulfite.

What is lime made from: The very name “quenched” already suggests that something was extinguished to obtain this substance. As everyone knows, any chemical compound(or anything at all) is usually extinguished with water. And she has something to react to. In chemistry, there is a substance called “quicklime.” So, by adding water to it, the desired compound is obtained.

Application: Slaked lime is used for whitewashing any room. It is also used to soften water: if you add fluff to calcium bicarbonate, hydrogen oxide and an insoluble precipitate are formed - the carbonate of the corresponding metal. Slaked lime is used in tanning leather, causticizing sodium and potassium carbonates, producing calcium compounds, various organic acids and many other substances.

Using a solution of "fluff" - the well-known lime water - you can detect the presence of carbon dioxide: when it reacts with it, it becomes cloudy (photo). Dentistry cannot do without the calcium hydroxide now being discussed, because thanks to it, in this branch of medicine it is possible to disinfect the root canals of teeth. Lime mortar is also made using slaked lime by mixing it with sand. A similar mixture was used in ancient times, then not a single building masonry could do without it. However, now, due to the unnecessary release of water during the reaction of the fluff with sand, this solution is successfully replaced with cement. Calcium hydroxide is used to produce lime fertilizers, it is also a food additive E526... And many other industries cannot do without its use.

Quicklime – Quicklime (unrefined calcium oxide) is produced by calcining limestone containing very little or no clay. It combines very quickly with water, releasing a significant amount of heat and forming slaked lime (calcium hydroxide).

Quicklime has many beneficial properties, due to this it finds wide application in construction, industry agriculture.

Properties: finely porous pieces of CaO 5…10 cm in size, obtained after firing the raw materials, average density 1600…1700 kg/m3.
Depending on the content of magnesium oxide, air lime is divided into calcium (70...90% CaO and up to 5% MO), magnesian (up to 20% Mg0) and high-magnesium or dolomite (Mg0 from 20 to 40%).
Quicklime is produced in three grades. Depending on the slaking time, all types of lime are distinguished: fast-slaking lime (slaking time up to 8 minutes); medium-extinguishing (up to 25 minutes), slow-extinguishing (over 25 minutes).

Construction aerial lime is divided into three grades.
The density of quicklime ranges from 3.1-3.3 g/cm3 and depends mainly on the firing temperature, the presence of impurities, underburning and overburning.
The density of hydrated lime depends on the degree of its crystallization and is equal to 2.23 for Ca(OH)2, crystallized in the form of hexagonal plates, and 2.08 g/cm3 for amorphous lime.
Volumetric mass of lump quicklime in
piece largely depends on the firing temperature and increases from 1.6 g/cm3 (lime fired at a temperature of 800 ° C) to 2.9 g/cm3 (long-term firing at a temperature of 1300 ° C).
The volumetric mass for other types of lime is as follows: for ground quicklime in a loosely poured state 900-1100, in a compacted state 1100-1300 kg/m3; for hydrated lime (fluff) in a loosely poured state - 400-500, in a compacted state 600-700 kg/m3; for lime dough - 1300-1400 kg/m3.
Plasticity, which determines the ability of the binder to impart workability to mortars and concrete, is the most important property of lime. The plasticity of lime is associated with its high water-holding capacity. Finely dispersed particles of calcium oxide hydrate, adsorption holding a significant amount of water on their surface, create a kind of lubricant for aggregate grains in a mortar or concrete mixture, reducing friction between them. As a result of this lime mortars They have high workability, are easily and evenly distributed in a thin layer on the surface of brick or concrete, adhere well to them, and are characterized by water-holding ability even when applied to brick and other porous substrates.

Application: This substance is widely used in different areas human activity. The largest consumers include: ferrous metallurgy, agriculture, sugar, chemical, pulp and paper industries. CaO is also used in the construction industry. Special significance connection has in the field of ecology. Lime is used to remove sulfur oxide from flue gases. The compound is also capable of softening water and precipitating organic products and substances present in it. In addition, the use of quicklime ensures the neutralization of natural acidic and waste water. In agriculture, upon contact with soils, the compound eliminates acidity that is harmful to cultivated plants. Quicklime enriches the soil with calcium. Due to this, the cultivability of the land increases and the rotting of humus accelerates. At the same time, the need to apply nitrogen fertilizers in large doses is reduced.

The hydrate mixture is used in poultry and livestock farming for feeding. This eliminates the lack of calcium in the diet. In addition, the compound is used to improve general sanitary conditions when keeping and breeding livestock. In the chemical industry, hydrated lime and sorbents are used to produce calcium fluoride and hydrochloride. In the petrochemical industry, the compound neutralizes acid tars and also acts as a reagent in basic inorganic and organic synthesis. Lime is widely used in construction. This is due to the high environmental friendliness of the material. The mixture is used in the preparation of binding materials, concrete and mortars, and the production of products for construction.

Corrosion of metals and methods of corrosion protection

Metal corrosion- the process of destruction of metals and alloys due to chemical or electrochemical interaction with the external environment, as a result of which the metals oxidize and lose their inherent properties. Corrosion is the enemy metal products. Every year in the world, 10...15% of smelted metal is lost as a result of corrosion, or 1...1.5% of all metal accumulated and exploited by humans.

Chemical corrosion- destruction of metals and alloys as a result of oxidation when interacting with dry gases at high temperatures or with organic liquids - petroleum products, alcohol, etc.

Electrochemical corrosion- destruction of metals and alloys in water and aqueous solutions. For corrosion to develop, it is enough that the metal is simply covered the thinnest layer adsorbed water (wet surface). Due to the heterogeneity of the metal structure during electrochemical corrosion, galvanic pairs (cathode - anode) are formed in it, for example, between metal grains (crystals) that differ from one another in chemical composition. Metal atoms from the anode enter the solution in the form of cations. These cations, combining with the anions contained in the solution, form a layer of rust on the metal surface. Metals are mainly destroyed by electrochemical corrosion.

Corrosion of metals causes great economic damage; as a result of corrosion, equipment, machines, mechanisms fail and are destroyed metal structures. Particularly susceptible to corrosion of equipment in contact with aggressive environment, for example, solutions of acids and salts.

At normal conditions metals can enter into chemical reactions with substances contained in the environment - oxygen and water. Spots appear on the surface of metals, the metal becomes brittle and cannot withstand loads. This leads to the destruction of metal products for the manufacture of which it was spent large number raw materials, energy and the amount of human effort.
Corrosion is the spontaneous destruction of metals and alloys under the influence of environment.
A striking example of corrosion is rust on the surface of steel and cast iron products. Every year, about a quarter of all iron produced in the world is lost due to corrosion. Costs for repair or replacement of ships, vehicles, instruments and communications, water pipes many times higher than the cost of the metal from which they are made. Corrosion products pollute the environment and negatively affect people's lives and health.
Chemical corrosion occurs in various chemical industries. In an atmosphere of active gases (hydrogen, hydrogen sulfide, chlorine), in an environment of acids, alkalis, salts, as well as in molten salts and other substances, specific reactions occur involving metal materials, from which the apparatus in which the chemical process is carried out is made. Gas corrosion occurs at elevated temperatures. Furnace fittings and parts of internal combustion engines fall under its influence. Electrochemical corrosion occurs when metal is contained in any aqueous solution.
Most active ingredients environmental agents that act on metals are oxygen O2, water vapor H2O, carbon (IV) oxide CO2, sulfur (IV) oxide SO2, nitrogen (IV) oxide NO2. The corrosion process is greatly accelerated when metals come into contact with salt water. For this reason, ships rust in sea ​​water faster than in fresh water.
The essence of corrosion is the oxidation of metals. Corrosion products can be oxides, hydroxides, salts, etc. For example, iron corrosion can be described schematically by the following equation:
4Fe + 6H2O + 3O2 → 4Fe (OH) 3.
It is impossible to stop corrosion, but it can be slowed down. There are many ways to protect metals from corrosion, but the main technique is to prevent the iron from coming into contact with air. To do this, metal products are painted, varnished or coated with a layer of lubricant. In most cases, this is enough to prevent the metal from deteriorating for several tens or even hundreds of years. Another way to protect metals from corrosion electrochemical coating metal or alloy surfaces with other metals that are resistant to corrosion (nickel plating, chrome plating, galvanization, silver plating and gold plating). In technology, special corrosion-resistant alloys are often used. To slow down the corrosion of metal products in an acidic environment, special substances are also used - inhibitors.

Life and work of A.M.Butlerov

Alexander Butlerov was born in 1828 in Butlerovka, a small village near Kazan, where his father’s estate was located. Sasha did not remember his mother; she died 11 days after his birth. Raised by his father, an educated man, Sasha wanted to be like him in everything.

At first he went to a boarding school, and then entered the First Kazan Gymnasium, whose teachers were very experienced, well prepared, and they knew how to interest students. Sasha easily learned the material, since from early childhood he was taught to work systematically. He was especially attracted to the natural sciences.

After graduating from high school, against the wishes of his father, Sasha entered the natural science department of Kazan University, although for now only as a student, since he was still a minor. Only the next year, 1845, when the young man was 17 years old, his name appeared on the list of those admitted to the first year.

In 1846, Alexander fell ill with typhus and miraculously survived, but his father, who became infected from him, died. In the fall, together with their aunt, they moved to Kazan. Gradually, youth took its toll, and Sasha’s health and fun returned. Young Butlerov studied with exceptional diligence, but, to his surprise, he noticed that the greatest pleasure was given to him by lectures on chemistry. Professor Klaus's lectures did not satisfy him, and he began to regularly attend lectures by Nikolai Nikolaevich Zinin, which were given to students of the physics and mathematics department. Very soon Zinin, watching Alexander during laboratory work, noticed that this fair-haired student was unusually gifted and could become a good researcher.

Butlerov studied successfully, but increasingly thought about his future, not knowing what he should ultimately choose. Do you want to study biology? But, on the other hand, is the lack of a clear idea of organic reactions Doesn't it offer endless possibilities for exploration?

To receive a candidate's academic degree, Butlerov had to submit a dissertation upon graduation. By this time, Zinin had left Kazan for St. Petersburg and he had no choice but to study the natural sciences. For his PhD thesis, Butlerov prepared an article “Day butterflies of the Volga-Ural fauna.” However, circumstances were such that Alexander still had to return to chemistry.

After approval by the Council scientific degree Butlerov remained to work at the university. The only chemistry professor, Klaus, could not teach all the classes himself and needed an assistant. Butlerov became it. In the fall of 1850, Butlerov passed exams for a master's degree in chemistry and immediately began his doctoral dissertation “On essential oils", which he defended at the beginning next year. In parallel with preparing the lecture, Butlerov began a detailed study of the history of chemical science. The young scientist worked hard in his office, in the laboratory, and at home.

According to his aunts, they old apartment The ball was uncomfortable, so they rented another, more spacious one from Sofia Timofeevna Aksakova, an energetic and decisive woman. She accepted Butlerov with maternal care, seeing in him a suitable match for her daughter. Despite his constant employment at the university, Alexander Mikhailovich remained a cheerful and sociable person. He was by no means distinguished by the notorious “professorial absent-mindedness,” and his friendly smile and ease of manner made him a welcome guest everywhere. Sofya Timofeevna noted with satisfaction that the young scientist was clearly not indifferent to Nadenka. The girl was really pretty: a high, intelligent forehead, large sparkling eyes, strict, regular facial features and some kind of special charm. The young people became good friends, and over time they began to increasingly feel the need to be together, sharing their most secret thoughts. Soon Nadezhda Mikhailovna Glumilina, the niece of the writer S.T. Aksakova became the wife of Alexander Mikhailovich.

Butlerov was known not only as an outstanding chemist, but also as a talented botanist. He conducted various experiments in his greenhouses in Kazan and Butlerovka, wrote articles on the problems of gardening, floriculture and agriculture. With rare patience and love, he watched the development of delicate camellias and lush roses, and developed new varieties of flowers.

On June 4, 1854, Butlerov received confirmation that he had been awarded the academic degree of Doctor of Chemistry and Physics. Events unfolded with incredible speed. Immediately after receiving his doctorate, Butlerov was appointed acting professor of chemistry at Kazan University. At the beginning of 1857, he already became a professor, and in the summer of that year he received permission to travel abroad.

Butlerov arrived in Berlin at the end of summer. He then continued to tour Germany, Switzerland, Italy and France. The final destination of his trip was Paris, the world center of chemical science at that time. He was attracted, first of all, by his meeting with Adolf Wurtz. Butlerov worked in Wurtz's laboratory for two months. It was here that he began his experimental research, which over the next twenty years culminated in the discovery of dozens of new substances and reactions. Butlerov's numerous exemplary syntheses of ethanol and ethylene, tertiary alcohols, and the polymerization of ethylene hydrocarbons lie at the origins of a number of industries and, thus, had a very direct stimulating effect on it.

While studying hydrocarbons, Butlerov realized that they represent a completely special class chemicals. Analyzing their structure and properties, the scientist noticed that there is a strict pattern here. It formed the basis of the theory of chemical structure he created.

His report at the Paris Academy of Sciences aroused general interest and lively debate. Butlerov said: “Perhaps the time has come when our research should become the basis new theory chemical structure of substances. This theory will be distinguished by the accuracy of mathematical laws and will allow one to predict the properties organic compounds" No one has expressed such thoughts until now.

A few years later, during his second trip abroad, Butlerov presented the theory he had created for discussion. He made a report at the 36th Congress of German Naturalists and Doctors in Speyer. The congress took place in September 1861.

He made a presentation to the chemical section. The topic had a more than modest title: “Something about the chemical structure of bodies.”

Butlerov spoke simply and clearly. Without going into unnecessary details, he introduced the audience to a new theory of the chemical structure of organic substances: his report aroused unprecedented interest.

The term “chemical structure” had been used before Butlerov, but he rethought it and used it to define a new concept about the order of interatomic bonds in molecules. The theory of chemical structure now serves as the basis for all modern branches of synthetic chemistry without exception.

So, the theory declared its right to exist. She demanded further development, and where else, if not in Kazan, should this be done, because a new theory was born there, its creator worked there. For Butlerov, rector's duties turned out to be a heavy and unbearable burden. He asked several times to be relieved of this position, but all his requests remained unsatisfied. His worries did not leave him at home either. Only in the garden, tending to his favorite flowers, did he forget the worries and troubles of the past day. His son Misha often worked with him in the garden; Alexander Mikhailovich asked the boy about the events at school and told interesting details about the flowers.

The year 1863 came - the happiest year in the life of the great scientist. Butlerov was on the right track. For the first time in the history of chemistry, he managed to obtain the simplest tertiary alcohol - tertiary butyl alcohol, or trimethylcarbinol. Soon after this, reports appeared in the literature about the successful synthesis of primary and secondary butyl alcohols.

Scientists have known isobutyl alcohol since 1852, when it was first isolated from natural vegetable oil. Now there could be no question of any dispute, since there were four different butyl alcohols, and all of them were isomers.

In 1862 - 1865, Butlerov expressed the main position of the theory of reversible isomerization of tautomerism, the mechanism of which, according to Butlerov, consisted in the splitting of molecules of one structure and the combination of their residues to form molecules of a different structure. It was a brilliant idea. The great scientist argued for the need for a dynamic approach to chemical processes, that is, to consider them as equilibrium.

Success brought confidence to the scientist, but at the same time presented him with a new, more difficult task. It was necessary to apply the structural theory to all reactions and compounds organic chemistry, and most importantly, write a new textbook on organic chemistry, where all phenomena would be considered from the point of view of a new theory of structure.

Butlerov worked on the textbook for almost two years without a break. The book “Introduction to a Complete Study of Organic Chemistry” was published in three editions between 1864 and 1866. It could not be compared in any way with any of the textbooks known at that time. This inspired work was a revelation of Butlerov, a chemist, experimenter and philosopher, who reconstructed all the material accumulated by science according to a new principle, according to the principle of chemical structure.

The book caused a real revolution in chemical science. Already in 1867, work began on its translation and publication in German. Soon after this, publications were published on almost all major European languages. According to German researcher Victor Meyer, it became " guiding star"in the vast majority of research in the field of organic chemistry.

Since Alexander Mikhailovich finished working on the textbook, he increasingly spent time in Butlerovka. Even during academic year the family went to the village several times a week. Butlerov felt free from worries here and devoted himself entirely to his favorite hobbies: flowers and insect collections.

Now Butlerov worked less in the laboratory, but closely followed new discoveries. In the spring of 1868, on the initiative of the famous chemist Mendeleev, Alexander Mikhailovich was invited to St. Petersburg University, where he began to lecture and was given the opportunity to organize his own chemical laboratory. Butlerov developed new technique training of students, offering the now universally accepted laboratory workshop, in which students were taught how to work with a variety of chemical equipment.

Along with his scientific activities, Butlerov is actively involved in social life St. Petersburg. At that time, the progressive public was especially concerned about the issue of women's education. Women should have free access to higher education! Higher Women's Courses were organized at the Medical-Surgical Academy, and classes began at the Bestuzhev Women's Courses, where Butlerov lectured on chemistry.

Multilateral scientific activity Butlerova found recognition from the Academy of Sciences. In 1871 he was elected extraordinary academician, and three years later - ordinary academician, which gave him the right to receive an apartment in the Academy building. Nikolai Nikolaevich Zinin also lived there. The close proximity further strengthened the long-standing friendship.

The years passed inexorably. Working with students became too difficult for him, and Butlerov decided to leave the university. He gave a farewell lecture on April 4, 1880 to second-year students. They greeted the news of the departure of their beloved professor with deep sadness. The Academic Council decided to ask Butlerov to stay and elected him for another five years.

The scientist decided to limit his activities at the university to only reading the main course. And yet he appeared in the laboratory several times a week and supervised the work.

Throughout his life, Butlerov carried another passion - beekeeping. On his estate he organized an exemplary apiary, and in recent years life is a real school for peasant beekeepers. Butlerov was almost more proud of his book “The Bee, Its Life and the Rules of Intelligent Beekeeping” than his scientific works.

Butlerov believed that a real scientist should also be a popularizer of his science. In parallel with scientific articles, he published publicly available brochures in which he spoke brightly and colorfully about his discoveries. He completed the last of them six months before his death.

Achieving any goal is daily work. If your goal is to receive good harvest, then you will need not only to invest your labor, but also to provide your garden and vegetable garden with proper care, attention and care. Definitely an experience many years He taught everyone that when growing anything in the garden, you cannot do without chemicals.

Most likely, everyone has heard about slaked lime in one area of ​​conversation or another. Slaked lime (or, as it is also called, fluff) has a chemical name - calcium hydroxide. It is interesting that such lime is used in various fields: construction, water softening, leather tanning, dentistry, chemical industry. It has also been used in gardening.

The composition of slaked lime is quite simple; calcium oxides predominate in it. The process of obtaining (quenching) is also not complicated, and consists of adding water and thoroughly mixing.

Preparing slaked lime (fluff) is not difficult; to do this, you need to quench it (mix it) with water, which takes about 10-20 minutes. During the extinguishing process, a safe, healthy fertilizing is performed.

The main rule is that the slaking water must be cold so that the lime does not lose its beneficial substances.

The use of slaked lime is quite widespread in gardening. A simple, unpretentious method has long become one of the main tools for experienced gardeners. Some of the application methods:

• Weed control: Some types of weeds can be completely removed from the garden by autumn period liming the soil. Application rate - 300-400 g per sq.m. After the procedure, you will not be afraid of weeds: horsetail, wheatgrass, wood lice, horse sorrel.
• Slaked lime can also be added to compost pit- this way you will speed up the process of decomposition of its contents.
• Deoxidation of soil using liming requires compliance with norms and doses: heavy and clay soils - 600-900 g. per sq.m., light, loamy - 400-500 gr. per sq. m, light, sandy - 300-400 gr. per sq.m. Liming of the soil is carried out once every 3-4 years.
• The process of whitewashing trees is very simple. It is recommended to use premium or first grade lime. Dilute the lime to obtain a rich white color, the approximate proportion is 1:1.

Difference between slaked and quicklime

It would be logical to think that if slaked lime exists, then there must be quicklime. How does it differ from slaked, and where is it used? No matter how contradictory it may sound, the word “lime” is of Greek origin and means “unquenchable.”

Quicklime has a granular appearance. Previously, quicklime could be used for construction work as cement, however, as a result of this application, it was noticed that it was not best properties, namely, the absorption of moisture and the proliferation of fungal mold. Despite this, quicklime is widely used in construction for the production of slag concrete, paints, sand-lime bricks, and plastering materials. In the food industry, quicklime acts as an emulsifier, helping to bind substances whose properties do not allow them to dissolve in each other. Quicklime is also used in the process of neutralizing wastewater and flue gases.

The main difference between slaked and quicklime is the chemical formula. Slaked lime is calcium hydroxide, quicklime is calcium oxide. Unlike slaked lime, which is most often found in powder form, quicklime is granular.

Lime slaking rules and safety precautions

Dehydration is the process of slaking lime. Before you start working with lime, be sure to take all safety precautions:

• your clothes should be tight, work in gloves, a respirator, and safety glasses;
• Extinguishing must be done exclusively in a metal container;
• if extinguishing is carried out indoors, ensure good ventilation;
• If lime gets into your eyes or skin, you should rinse the affected area with a weak vinegar solution or plenty of water, and then consult a doctor.

Dehydration is carried out in an open space. According to the speed of extinction they are distinguished:

• quick-quenching lime - up to 8 minutes;
• medium-slaking lime - up to 25 minutes;
• slow slaking lime - more than 25 minutes.

The slaking process is the addition of water to quicklime. Adding water should be done slowly so as not to reduce the temperature, because Heat is released during the extinguishing process.

Lime must be stored under certain conditions. Prepare a pit for storage, sprinkle the solution on top with a 20 cm layer of sand (if storage is expected in frost, then a 50-70 cm layer of earth can be added on top of the sand). Fence the pit for the safety of people and animals.

Features of using fluff in the garden

Slaked lime is an organic substance. The main elements of fluff are calcite and dolomite. As already mentioned, slaked lime can be used as fertilizer and as protective agent in the garden and vegetable garden.

Rich in potassium, magnesium and calcium, fluff has quickly gained popularity in gardening. Moreover, the potassium included in the composition has a form that is quickly absorbed by plants. Calcium should be part of the soil, it is responsible for plant immunity, protection against diseases, therefore slaked lime is economical and effective option to replenish the soil with calcium. In addition to its direct effect, calcium activates the activity of microorganisms, and they begin to release nitrogen. The use of fluff promotes change chemical composition soil, its normalization and acquisition necessary functions and components.

The most popular and practical material, which has found its wide application in construction, repair, agriculture and everyday life, is slaked lime.

It is the main component of modern coatings, mixtures and solutions with high performance characteristics. Read more about how to properly slak and store lime, as well as for what purposes it can be used.

Slaked lime is a chemical powdery compound of inorganic form (Ca(OH) 2), which can be obtained by the interaction of calcium oxide ( quicklime) and water.

When producing hydrated lime it is important to maintain the correct temperature regime heating water, which should not exceed 500 degrees. The higher the water temperature, the lower the quality of the finished product.

Depending on the extinguishing method, the following types of compositions can be formed:

• Lime water.
• Lime milk (suspension).
• Lime dough.
• Fluff (calcium hydroxide in powder form).

Differences between slaked and quicklime

The difference between slaked and quicklime lies in the chemical formula and properties of the substance.

The distinctive characteristics of the two substances are clearly presented in the table.

You can distinguish slaked lime from the source material not only visually, but also tactilely - it is not capable of releasing thermal energy, so it always remains cold.

Quicklime is a rock that is obtained by burning chalk or limestone rocks at temperatures above 1000 degrees. As a result of its high hygroscopicity, the material is rarely used in its pure form. It is designed for preparing various mortars, mixtures and elements.

Instructions for slaking lime

The lime slaking process can be organized at a construction site or at home. Depending on the type of raw material, the finished solution is:

• Quick-extinguishing (cooks in 10 minutes).
• Medium-extinguishing (extinguishing within 25 minutes).
• Slow-cooking (takes up to 1 hour to cook).

The duration of quenching is determined by the time from the beginning of adding water to the feedstock until the chemical composition of the finished product is completely stabilized.

Preparatory stage

For work it is necessary to prepare raw materials and means personal protection from negative impact thermal steam – gloves, goggles, mask, clothing made of thick fabric.

The raw material should be lime in quicklime form, deep wooden or metal container and a kneading device.

Also, to prepare a large volume of the mixture you will need an earthen pit and a spacious box made of wooden base, equipped with a drain window with a mesh filter.

Quenching process

To obtain high-quality hydrated lime, the following steps are performed:

1. The raw materials are poured into the prepared container.
2. Water is gradually added to the base in a 1:1 ratio and slowly stirred to activate the quenching process. This proportion is suitable for preparing fluff - a powdery mixture. To obtain lime dough or milk, 400 g of water must be added to 1 kg of raw materials.
3. Stirring of the substance is carried out until the quenching reaction is completely completed.
4. The freshly slaked solution is infused in a container for 40 hours until thickened, and used 30 days after preparation.

Cancellation in a wooden box

If a wooden box was used to prepare the lime, ready mix it is drained through a filter window into an earthen pit, covered with boards and infused for several days.

After the end of the period, the lime is covered with a sand layer 18 cm high and further infused for 2–3 weeks.

Lime storage rules

Hydrated lime is a long-term storage product that does not change its chemical structure and does not lose beneficial properties throughout the entire service life.

• After dehydration is completed, the duration of exposure of the material is: for the preparation of mortars and elements - 2 weeks, for plastering - 30 days.
• At winter storage material in the pit, an additional thermal insulation cushion is installed: up to 20 cm of sand and 70 cm of soil. You can also use solid insulation.
• Storage of material in packages is allowed in well-ventilated warehouses with concrete, asphalt and brick floors. Warehouses must have the necessary fire safety equipment: wooden boxes with sand, fire extinguishers with carbon dioxide, fire hydrants with hydraulic hoses.
• Slaked lime should not be stored near explosive or flammable substances.

Due to its unique characteristics, slaked lime has long been used in modern construction, medicine, gardening and everyday life.

Application in construction

Widespread use of lime in construction to solve the following problems:

• Internal whitewashing of indoor surfaces.
• Preparation of mortars, binding mixtures and coloring compositions.
• Protection wooden structures from fire and rotting.
• Production of wood concrete, cinder blocks, silicate brick blocks and heavy concrete.
• Preparation of masonry composition for the construction of furnace structures.
• Production of lime cement mortar.
• Preparation of lime water for the determination of carbon dioxide compounds.

Hydraulic characteristics ensure rapid hardening of ready-made mortars based on slaked lime. Therefore, they are often used in the construction of supporting elements of bridges and other structures of increased complexity.

Use in everyday life

Some ways to use the material in the household:

• Preparation of safe fertilizers to reduce soil acidity and control various pests.
• Preparation of a preventive solution for whitewashing the trunks of garden and ornamental trees.
• Preparation of mixtures to protect plants from fungal diseases, insects and small rodents.
• Preparation of an active additive for feeding birds and animals.
• Reduced hardness drinking water from wells, wells and water supply.
• Disinfection and disinfection various surfaces and wooden structures.
• Causticization of sodium or potassium carbonate.
• Neutralization of acidic compounds and organic-based acids.
• Tanning and processing of natural leather.
• Preparation of food supplements. The most common of them is an emulsifier (E526).

A unique material that has the following advantages: easy preparation, shelf life, excellent disinfection characteristics, wide range of uses. And the process of slaking lime at home is quite easy to learn. Ready-made solutions are successfully used for agricultural work, household repairs, construction of residential and commercial buildings, which is primarily due to the low cost of consumable raw materials.

Lime is a Greek word that has its own meaning. Literally translated, it means “unquenchable.” This is one of those materials that have been around since time immemorial. Humanity has been using it for its own purposes for a long time. Oddly enough, its properties were determined completely by accident. But they began to apply the material in many areas, through errors and trials, one might say, blindly. Lime is a versatile material that is still used today.

Due to its properties, the material is used in different industries, which differ from each other. In this article we will look at how the material is extracted, how slaked lime differs from quicklime and in what areas it is used.

History of the material

In ancient times, when people still did not understand anything about calcium and its compounds with oxygen and coal, they realized something. What exactly? Through “scientific poking” it was found that limestone has excellent properties, especially as building material. In addition, if you burn some rocks, such as limestone, dolomite, chalk, etc., you will get a substance that has binding properties.

If you remember the story ancient China, then workers stabilized the soil with limestone cement and laid the masonry of their famous Great Chinese wall. Its length is 2500 km. The amazing thing is that it has survived to this day, and today we can contemplate its greatness. Over time, lime has become a key component in the preparation of fertilizers used in agriculture.

There are two types of material: slaked and quicklime. How is this or that type obtained? What is the difference between them? Let's find out the answers to these questions.

Production of raw materials

We already know that lime is a product of rock. It is mined by firing in special kilns made of limestone, dolomite and chalk. The output is material in the form of white lumps, or as it is also called - lump “boil”. This is quicklime. The extraction process takes place in special factories, from where the lime is transported further. “Kipelka” is the initial product from which other types will be produced. Chemical formula material - CaO (calcium oxide).

The raw material, ready after firing, is not used for mortars and cement, as it has the ability to absorb moisture very strongly, and also contributes to the formation of fungal mold on the walls. Still, boiling water is quite in demand in construction industry, namely for the production of slag concrete, sand-lime brick, dyes and mixtures for plaster.

Depending on the time it takes to extinguish the lump “boil”, it is divided into 3 types. The first of them is quick-slaking lime. The time required to repay it is up to 8 minutes. The second type is medium-extinguishing, which reaches in 25 minutes. Well, the last type is slow-extinguishing, which needs 25 minutes or more to reach condition. So we smoothly moved on to another type of material - slaked lime.

Slaked lime

The differences between slaked and quicklime, how are they expressed? The name itself already shows what the difference between the materials is. If the usual raw material has the formula CaO, then the slaked material is obtained by adding water: CaO + H 2 O = Ca(OH) 2. This is the process of extinction. It is noteworthy that when the raw material is mixed with water, a violent reaction occurs, which releases a huge amount of heat and smoke. The water is literally boiling. That is why lump lime is called “boiling lime”. The output is hydrated fluff.

From the lump “boiler” you can get different subtypes: ground quicklime, hydrated fluff, limestone dough or milk. Depending on the amount of water added for quenching, dough or milk is obtained. For example, to obtain limestone dough, the reaction liquid requires 3-4 times more than the material itself. And if you need to get limestone milk, then the amount of liquid increases 8-10 times.

How to produce slaked fluff

To produce slaked lime, you need to follow some rules. Dehydration (quenching process) must be carried out in the open air. The raw materials themselves must be placed in a tank or container. Since quite a large amount of steam will be released during the process, you need to protect yourself. The material itself can also cause harm to humans and even burn the skin. That is why it is necessary to protect the skin of the hands and the entire body, eyes and respiratory tract. You cannot do without a suit or special clothing, gloves, goggles and a respirator. Then everything will be safe for your health.

It is important to remember that there is no need to rush in this matter. The qualities of quicklime can vary, some slak quickly, others take a long time. If you do not complete the whole thing, it is possible that the material will smoke in the finished plaster. When you use slow-slaking lime, it is not recommended to immediately fill it with water. It's better to do this in small portions. Medium and fast-extinguishing are poured until the steam completely disappears to prevent burnout.

Pay attention! Freshly slaked lime may have residues of the original material. They are extinguished again and then removed.

After dehydration, the amount of lime will be greater. From 1 kg of quicklime you can get 2 or more. Slaked lime and outstanding difference is obvious. But where are these materials used?

Application in construction

The main area in which slaked and quicklime is used is construction. Lime is wonderful binder material. One of its advantages is environmental friendliness and naturalness. It is completely harmless to humans. We have already spoken a little about the use of quicklime raw materials, but these are not all aspects. It is necessary for the production of dry construction mixture, mortar and plaster composition. In addition, by adding lime to concrete products, they become much stronger, more moisture resistant and denser.