most sought after 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 operational characteristics. Further on how to properly quench and store lime, as well as for what purposes it can be used.

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

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

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

• lime water.
• Lime milk (suspension).
• Lime paste.
• Pushonka (calcium hydroxide in powder form).

Differences between hydrated and quicklime

The difference between slaked lime 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.

Distinguish slaked lime from the source material is possible not only visually, but also tactilely - it is not able to highlight thermal energy so it always stays 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 pure form. It is designed to prepare various mortars, mixtures and elements.

Lime slaking instructions

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

• Fast-extinguishing (cooks in 10 minutes).
• Medium extinguishing (extinguishes within 25 minutes).
• Slow-extinguishing (requires up to 1 hour to cook).

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

Preparatory stage

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

Lime in quicklime form, a deep wooden or metal container and a kneading device should be used as raw materials.

Also, to prepare a large volume of the mixture, you will need an earthen pit and a capacious box 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 material is poured into the prepared container.
2. Water is gradually added to the base in proportions of 1: 1 and slowly stirred to activate the quenching process. This proportion is suitable for the preparation of fluff - a powder 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 completed.
4. A freshly slaked solution in a container is infused for 40 hours until it thickens, and is used 30 days after preparation.

Extinguishing in a wooden box

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

After the expiration of the term, the lime is covered with a sandy layer 18 cm high and additionally 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 its beneficial features throughout the entire period of operation.

• After completion of dehydration, 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 heat-insulating pillow is equipped: from sand up to 20 cm and soil - 70 cm. 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, carbon dioxide fire extinguishers, fire hydrants with hydraulic hoses.
• Slaked lime should not be stored near explosive and combustible substances.

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

Application in construction

The 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 decay.
• 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 provide fast curing of ready mortars based on slaked lime. Therefore, they are often used in the construction of supporting elements of bridges and other structures of increased complexity.

Application in everyday life

Some ways of using the material in the domestic sphere:

• Preparation of safe fertilizers to reduce soil acidity and control various pests.
• Preparation of a prophylactic 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.
• Decrease in hardness drinking water from wells, wells and water pipes.
• Decontamination and disinfection various surfaces and wooden structures.
• Caustification of sodium or potassium carbonate.
• Neutralization of acidic compounds and acids on an organic basis.
• Tanning and processing of natural leather.
• Preparation of food additives. The most common of them is an emulsifier (E526).

A unique material that has the following advantages: availability of preparation, shelf life, excellent disinfectant characteristics, wide scope of use. And the process of slaking lime at home is quite simple to learn. Ready solutions successfully used for agricultural work, household repair, 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 "inextinguishable". This is one of those materials that have been around since time immemorial. It has long been used by humanity for its own purposes. Oddly enough, its properties were determined quite by accident. But they began to apply the material in many areas, through errors and trials, one might say, blindly. Lime - universal material which is still in use 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 mined, how slaked lime differs from quicklime, and in what areas it is used.

The 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? By "scientific poke" it was found that limestone has excellent properties, especially as a building material. In addition, if you burn some rocks, such as the same limestone, dolomite, chalk, etc., then you get a substance with binding properties.

If we remember the history ancient China, then with limestone cement, the workers stabilized the soil and made the masonry of their famous Great Chinese wall. Its length is 2500 km. It is amazing that she has survived to this day, and today we can see her greatness. Over time, lime has become a key ingredient in the preparation of fertilizers used in agriculture.

There are two types of material: slaked and quicklime. How is one form or another 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 rock product. It is mined by firing in special kilns from limestone, dolomite and chalk. The output is a material in the form of white lumps, or as it is also called, a lumpy "boiler". This is quicklime. The extraction process takes place in special factories, from where the lime is delivered further. "Kipelka" is the initial product from which other species will be produced further. 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. Nevertheless, boiling water is quite in demand in the construction industry, namely for the manufacture of cinder concrete, sand-lime bricks, colorants and mixtures for plaster.

Depending on the time during which it is possible to extinguish the lump "boiler", it is divided into 3 types. The first of these is quick-extinguishing lime. The time it takes to pay it off is up to 8 minutes. The second type is medium-extinguishing, which reaches in 25 minutes. Well, the last type is slow-extinguishing, which takes 25 minutes or more to reach the condition. This is how we smoothly moved on to another type of material - slaked lime.

Lime slaked

Differences between slaked and quicklime, what are they expressed in? 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 \u003d Ca (OH) 2. This is the extinction process. It is noteworthy that when raw materials are mixed with water, a violent reaction occurs, during which a huge amount of heat and smoke is released. The water literally boils. That is why lump lime is called "boiling". The output is a hydrate fluff.

From the lump "boiler" you can get different subspecies: 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 is required 3-4 times more than the material itself. And if you need to get limestone milk, then the amount of liquid increases by 8-10 times.

How to make slaked fluff

For the production of slaked lime, you need to follow some rules. Dehydration (quenching process) must be carried out outdoors. The raw material itself must be placed in a tank or container. Since the process will stand out quite a large number of couple, you need to protect yourself. The material itself can also harm a person and even burn the skin. That is why it is necessary to protect the skin of the hands and the whole body, the eyes and the respiratory tract. You can not 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 quality of quicklime can vary, one is extinguished quickly, the other for a long time. If you do not bring the whole thing to an end, then it is possible that the material will smoke in the ready-made plaster. When you use slow-extinguishing lime, it is not recommended to immediately fill it with water. It is better to do it in small portions. Medium and quick-extinguishing are poured until the steam completely disappears to prevent burnout.

Note! 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 material, you can get 2 or more. Lime slaked and quicklime difference is obvious. But where are these materials used?

Application in construction

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

Lime is a word of Greek origin and means "inextinguishable". Belongs to those materials that have accompanied mankind since time immemorial. Its properties were discovered, probably by accident, and it found application in different areas through trial and error, so to speak, blindly. Consider the difference between hydrated and quicklime.

People still did not know anything about calcium and its compounds with coal and oxygen, but they already realized that mountain limestone is good. building material, and that by burning some rocks: limestone, chalk, dolomites and others, a substance with binding properties can be obtained.

With lime cement, the ancient Chinese stabilized the soil and fastened the masonry of their Great Wall 2500 km long, subsequently, fertilizers used in agriculture began to be made on the basis of lime.

Quicklime

Currently, quicklime obtained as a result of roasting is not used as cement, due to its ability to absorb moisture and cause fungal mold on walls, but in the construction industry it is in demand for the production of cinder concrete, paints, silicate bricks and plaster materials.

Quicklime (or calcium oxide mixed with other oxides, primarily magnesium oxide) is used to neutralize wastewater and flue gases, and to paint buildings. It is included in many food products in the form of an emulsifier, binding substances that by their nature resist dissolution in each other, such as water and oil.

Slaked lime

Hydrated (or hydrated) lime is formed as a result of interaction with water. Calcium oxide, of which quicklime is composed, is converted into calcium hydroxide, releasing heat abundantly in the form of steam.

Depending on the quenching method, we can get:

• lime water;
• suspension (milk of lime);
• dry calcium hydroxide (fluff).

Extinguishing method

Quicklime may differ in its qualities, so you should not rush into the process, but perhaps increase the slaking time so that poorly slaked lime does not smoke in freshly laid plaster that has been exposed to water.

Slow-extinguishing lime is best poured in several stages. A substance with a fast or medium extinguishing term is poured before the steam stops to avoid burnout. You should be careful not to let the boiling lime get on your hands and face. To avoid burns, protect yourself with long gloves, a respirator and special goggles.

In general, the features of the dosage of water in the process directly depend on the purpose of the future substance. General meaning domestic use of lime is to prevent unwanted activity of microorganisms.

Application

• lime fertilizers Since ancient times, they have been used in agriculture to increase soil fertility and for liming, that is, to reduce acidity. Solid calcareous fertilizers, such as chalk, limestone, dolomite, are ground or burned before being applied to the soil. Soft lime fertilizers act more efficiently and are applied to the soil without pre-treatment - natural dolomite flour, lake lime (garbage), calcareous tufa, marl. Lime fertilizers include rock processing products: quickburned lime (ground or lump) and fluff (slaked lime), as well as industrial waste, such as cement dust, belite flour, blast furnace slag, shale and peat ash, defecation mud, etc.
• Tree painting. Dilute 1 kg of lime in 4 liters of water. After a couple of days, the solution is ready for use.
• Spraying plants. Add to lime water blue vitriol and two hours after preparation, they begin to spray.
• Whitewashing of ceilings and walls. Here the proportion will be different: 1 kg of lime per 2 liters of water. Then add water until you get the desired consistency. Let the solution stand for a couple of days and strain it.
• Pushonka(or dry calcium hydroxide) perfectly copes with the functions of protecting against moisture, disinfecting and improving the binding qualities of cement and concrete mortars.

Enough already long time lime is used by many people in the field of construction and repair work. As a result of firing and special processing, this material is obtained.

To begin with, it is worth saying that there is slaked "fluff" and quicklime "boiling" lime. The first type is formed as a result of interaction with water.

It is worth noting that slaked lime has excellent astringent properties. Such material can be purchased at the store, or you can easily cook it yourself.

Slaked lime

To create the material, the same quicklime is used, or, as it is often called, calcium oxide. During contact with water, heat is released in the form of steam.

It should be noted that for quenching, different methods. Depending on the method chosen, completely different compositions can be obtained.

It must be said that quicklime may differ in some qualities. For example, if the composition is slow-extinguishing, then it is best to fill it several times.

If the substance is distinguished by a rapid quenching term, then the liquid is introduced until the vapor stops.

The resulting slaked composition is used in various fields. Most often, lime is used for the following purposes:

• creation of lime fertilizers (material is used in the form of chalk);
• spraying plants;
• disinfection of building materials.

Quite often slaked lime is used for painting trees. Diluted material is used for whitewashing ceilings and walls in the room.

Differences

Asking the question of how slaked lime differs from quicklime, it is necessary to pay attention to the following points:

• material properties;
• compound;
• application area.

It should be understood that the procedure for quenching the material completely changes the characteristics of lime. From the quicklime species, substances of different composition can be obtained.

In addition, it is necessary to pay attention to the scope of the material. Hydrated lime is widely used in construction and repair work, unlike the original version.

The material is used to make plaster mortar and silicate concrete. It should be noted that with the use of slaked lime, building compositions acquire higher performance characteristics.

Quite often, quicklime is used in Food Industry- it helps to mix substances that by their nature do not mix.

In construction, they were used only in slaked form. IV Smirnov in the thirties proposed to use the substance in a different way. He, and subsequently Osip B.V., showed that under certain conditions, hydrated hardening of the material can occur. This process is similar to the hardening of Portland cement or gypsum.

general information

Lime is a concept generally accepted throughout the world, which conditionally combines the products of roasting (and subsequently processing) of chalk, limestone and others. Classification is carried out in accordance with chemical composition. As a rule, the word "lime" refers to quicklime and the product of its interaction with water. This material may be in powdered, ground or dough form. The formula for quicklime is CaO. This compound is a product of roasting rocks, in which it acts as the main chemical component. It actively interacts with water. As a result of hydration, slaked lime is formed - Ca (OH) 2.

Classification

In accordance with the chemical composition, an air mixture (consisting mainly of magnesium and calcium oxides) and a hydrate mixture (containing a large amount of iron, aluminum and silicon oxides) are separated. In industry, quicklime construction lump and powder is used. The latter is also divided into two types. The first is ground quicklime. The second type is obtained by applying special technology. Slaked lime (fluff) is obtained by slaking magnesian, calcium and dolomitic lime using a limited amount of water. There are other types. These include, in particular, bleach and soda lime.

Production

Construction quicklime is produced using natural calcium-magnesium rocks. They mainly include and magnesium. They also include impurities of clay and sand. During heat treatment(when heated) in a furnace to a temperature of 800 to 1200 degrees, calcium-magnesium rocks begin to decompose. As a result of this process, (MgO) and calcium (CaO) are formed, as well as carbon dioxide.

Technology for obtaining a mixture of fine grinding

Ground quicklime is obtained by grinding the mixture in conventional ball mills. Their work is carried out in a closed cycle with a separator separating particles of the required size. In some cases, two separators are placed in series in the unit. This greatly increases productivity. To date, issues on fine grinding of lime have not been sufficiently developed. In the process of selecting mills and grinding schemes, it is necessary to take into account, first of all, the degree of firing of the material (heavy, medium or soft fired product). Be sure to take into account the presence of overburning, underburning, the presence of solid inclusions. It is more expedient to crush strongly and medium burnt lime, acting on its particles by abrasion and impact. This is what happens in ball mills. It should be noted that the tendency of solid particles to aggregate requires short mills and rapid removal of fine fractions from the total mass of the milled mixture, as well as the use of methods that reduce aggregation.

The use of quicklime and its products

This substance is widely used in various fields. human activity. The largest consumers include: agriculture, sugar, chemical, pulp and paper industries. CaO is also used in the construction industry. The connection is of particular importance in the field of ecology. Lime is used to remove sulfur oxide from flue gases. The compound is also able to soften water and precipitate organic products and substances present in it. In addition, the use of quicklime ensures the neutralization of natural acidic and waste water. In agriculture, in contact with soils, the compound eliminates acidity that is harmful to cultivated plants. Quicklime enriches the soil with calcium. Due to this, the workability of the land increases, and the decay of humus accelerates. At the same time, the need to apply nitrogen fertilizers in large doses is reduced.

The hydrated mixture is used in poultry and livestock for feeding. So eliminated in the diet. In addition, the compound is used to improve general sanitary conditions in the maintenance and breeding of livestock. AT 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 the main 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 binders, concretes and solutions, production of products for construction.

Lime quicklime finely ground. Advantages

Quicklime, as mentioned above, is used in the manufacture of concrete and mortar. This connection has a number of advantages. In particular, compared to hydrated lime in dough or powder form, the finely ground mixture does not leave any waste. At the same time, all its components are used most rationally during hardening. Ground quicklime is characterized by lower water demand. In addition, its specific surface area is also much smaller. In this regard, the "workability" of concrete or solution based on CaO is obtained with a reduced volume of water. Reducing the water demand of concrete and mortar mixtures helps to increase their strength during hardening. When hydrated in already prepared mixtures, lime binds more water (up to 32% upon transition to hydrate). This contributes to the production of products, concretes and solutions of increased density and strength. In the process of hydrated hardening of quicklime, a significant amount of heat is released. In this regard, products based on this compound at low (below zero) temperatures harden more calmly and have best performance strength, since the surrounding conditions provide rapid heat removal and reduction of thermal stresses. It is these advantages that determine the widespread use of CaO in the construction industry.

How are high-quality concrete and mortar mixtures obtained?

During hydrated hardening of quicklime nice results possible under certain conditions. First, the mixture must be finely ground. It is also necessary to maintain a certain ratio of lime and water. During the hardening process, optimal heat removal is necessary or other methods should be used that do not allow heating of hardening concretes or solutions to temperatures that can cause intense evaporation of moisture (especially during boiling). It is also important to stop mixing the mixture at a certain stage of the lime hydration process.

Storage and cost

The price of quicklime depends on the grade, type and quantity in which the material is needed. So, for example, the cost of a bag is from 300-400 rubles, and a ton - from 8-10 thousand rubles. The product is stored in warehouses with mechanized unloading and loading. The duration of the content of the compound should not be more than five to ten days (to avoid carbonization and hydration of calcium oxide). Quicklime lump or ground lime is sent to the consumer in containers, bituminized bags or in wagons equipped for its transportation, or in cement trucks. Packaging in bags is carried out using modern units with shaking devices. In bags, the product should be stored for no longer than fifteen days.