Slaked lime: characteristics and scope of application

Slaked lime - a substance of chemical origin, which is used by man in many fields of activity. No exception is the scope of repair work. But for the work to be really productive, it is important to apply the composition correctly. In order to avoid mistakes, it is necessary to get acquainted in advance with the characteristics of the slaked substance, various classifications of compositions and recommendations for their proper use.

Slaked lime is a substance that is formed by mixing water and calcium oxide. In another, such lime is called fluff. Upon receipt of hydrated lime, such an amount of energy is released that would be enough to boil water or ignite a tree.An important role in the formation of the hydrated composition is played by the temperature of the water, with which quicklime reacts. Sometimes this substance is obtained by burning coal.

Slaked lime is a white powder. Sometimes it has the appearance of white crystals that withstand exposure to fairly high temperatures, up to 560 degrees. However, if the temperature exceeds this value, then the reverse process of decomposition into burnt lime and water occurs. The composition does not dissolve in alcohol. Its chemical formula is as follows: Ca (OH) 2.

The material has several valuable advantages:

• able to protect the surface from moisture;
• has a disinfecting effect;
• improves the quality of various concrete and cement solutions.

A slight drawback is the impossibility of using such a substance for finishing works. It is usually used as an intermediate layer.

Hydrated lime is different. It is the membership of a particular variety that determines the characteristics of its scope. There are several types of classifications for this substance.

The first sign is the time it takes to quench the calcium oxide. There are several types.

• Fast-drying composition is extinguished in no more than 10 minutes (regardless of the initial volume). Sometimes the process takes place even in less time.
• Quenched with medium speed lime usually changes its composition in a quarter of an hour.
• When the duration of the chemical process exceeds 30 minutes, lime is classified as slow-extinguishing.

The second sign of the classification of a slaked limestone mixture is the size of its fractions.

There are compositions of different grinding.

• Lump lime has the largest fraction, it is usually produced in tons.
• Composition with medium fractions - crushed lime. Such a product is usually stored in mounds and warehouses.
• In smaller batches sold powdered material. One pack usually weighs a few pounds.

The composition of the material may include various axidic inclusions.

According to this characteristic, substances are divided into:

• calcium (usually used for masonry);
• dolomitic (well deoxidize the soil);
• magnesia compositions (used for plastering surfaces).

An important characteristic is the feature of the hardening of the limestone composition.

This process can occur in two ways, which subsequently determine the scope of the composition.

• Hydraulic hardening forms substances used to impart additional strength. They are added to solutions used for work in direct contact with water. Such a product is used in the construction of port fortifications or bridges. It is characterized by a viscous composition and consistency similar to dough. There are also strongly hydraulic and weakly hydraulic varieties of such a substance.

• Air hardening provides a composition that is less viscous in consistency. This material is often used in the construction industry. Often it is used to make plaster, various coloring mixtures and mortar solutions. The main function of such a product is to strengthen the hardening of various solutions in conditions with low humidity levels. In combination with calcium carbonate, similar lime is used to make some building mixtures (Portland cement and others).

A special place in limestone hydrates is occupied by freshly calcined lime. It is the same calcium hydroxide. The difference is that no more than 6 hours should pass from the moment it is extinguished. This composition is usually suitable for making milk of lime.

Lime, being a viscous inorganic substance, in combination with asbestos fibers can also take on special forms and form derived materials. These products include asbestos cardboard and asbestos paper.

Hydrate lime, as well as any building material of chemical origin, has a number of technical parameters, officially fixed by GOST 9179-77.

There are several basic characteristics of this material.

• The composition of this building mixture may include the following components: mineral additives, such as electrothermophosphorus, granulated or blast furnace slags, quartz sand, active mineral additives, carbonate rocks. All substances must comply with the requirements of special regulatory documents.
• The type of hydraulic lime is characterized by such properties as compressive strength.

• Both air and hydraulic compositions are considered suitable for use if they remain uniform with volume changes.
• The quality of varieties of lime compounds is determined by the ratio of calcium and magnesium oxides with water. First-class product contains 90% of these substances in relation to the percentage of water content. The reduction in quality is directly proportional to the amount of magnesium and calcium.
• Fluff should have a specific weight in the range from 450 to 550 m3.
• Calcium hydroxide must comply with specific physical indicators, such as strength. It is checked 28 days after the substance has been manufactured when it is bent and compressed.
• The acidity of the composition should be 12.4 pKa.
• The density of a substance is 2, 211 g / cm3.

Slaked lime is used in various branches of human activity.

This substance has become indispensable in many types of work, as well as in everyday life.

• In the garden or vegetable garden hydrated lime is needed in order to lime the soil. This procedure significantly increases the fertility of the soil. Due to liming, the level of acidity of the earth is reduced, favorable conditions are created for growing various crops. Also, calcareous compounds save many plants from pests and parasitic larvae.

• Since the substance is capable of imparting strength to various materials, they are often covered with wooden structures (benches, hedges, gazebos and even pegs in the beds). Also, this coating protects various buildings from fire.
• In certain seasons whitewashing of garden trees is carried out with the help of quicklime. They are covered with a special solution based on hydrated lime, which saves the plants from the influence of temperature differences.
• To prevent the formation of mold on garden tools or in rooms such as cellars, calcium hydroxide is also used.

In addition to gardening pushonka actively used in many construction works and some other areas.

• Calcium hydroxide is used for brickwork. It creates high adhesion both with a brick surface, and with slag-block materials.
• In order to save on construction work, lime-mortar, well-known from antiquity, is sometimes made by mixing slaked lime with sand.
• On the basis of calcium hydroxide is made such a composition as bleach. It is an excellent disinfectant.

• The substance is used for the manufacture of a special type of concrete - silicate. It is characterized by faster hardening.
• With the help of this substance whitewashing is carried out not only the street structures and trees, but also the walls and ceilings in the room.
• Slaked lime is a part of calcium-based compounds, thanks to which water is purified.

• Fluff used for tanning leather.
• Calcium hydroxide is used for dental procedures such as cleaning the dental canals.
• Slaked lime is added even to food. Substance is applied as a part of the additive E526.

Pushonka is actively used in various industries:

• metallurgical;
• chemical;
• sugar;
• construction;
• pulp and paper.

Usually pushonu do in the factory. This product turns out better. Quenching is carried out with the help of a hydrator in a special container. The second third of the tank is filled with water, and the last empty part remains for lime, because the volume of the substance increases during the reaction.

Lime can be used directly at the construction site. However, the products made at the plant have a longer shelf life than the product produced in stationary conditions. After a time, the properties of such a mixture also improve.

There are 3 ways to create hydrated lime.

• In the first embodiment, lime lumps are used. They are laid out in layers with a thickness of 0, 25 m. From above these layers are watered with water. Also add wet sand. After a couple of days, the quenching process will be completed and the mixture will be ready for use.
• In the second variant, it is necessary to dig a hole and install a wooden box in it, at the bottom of which there should be a flap of fine mesh. Lumpy material is placed in a box, then it must be filled with water. Liquid is added as lumps break up into smaller fractions. As soon as the quenching process occurs, it will be necessary to drain the excess water through the damper, the mixture should be filled up with a 10-cm layer of sand. This technique protects the composition from drying.

• The third option involves slaking lime by mixing it with water. Prepare a solution of calcium hydroxide, using the third method, you can independently by analogy with the production process.

It is important to follow a specific algorithm of action.

• Take care of safety measures.To do this, be sure to wear heavy clothing, gloves and protect your eyes. Remember that if the composition gets on the eye mucosa, vision can suffer greatly.
• Use a plastic container for dilution. If you choose a metal container, check it for rust. Such entities should not be.

• An ordinary wooden stick or even a cutting from a garden device will be suitable as a tool for mixing the composition.
• Before preparing the mixture, measure the required amount of dry lime and calculate its proportions with water. Remember that the substance consumption per 1 square. m. will depend on its consistency and the number of layers that you plan to apply to the surface.
• First add lime to the container and then add water in portions. At the same time be sure to stir the composition throughout the time. Water should be cold. If you add high or even room temperature water, the quality of the final composition will deteriorate significantly.

• The readiness of the solution can be determined by the trace on the stick. If it has a pronounced white shade, then the composition has reached readiness.
• For the solution to infuse, after mixing, it should be left for some time. If possible, wait a few days, but if there is no such possibility, insist hydrated lime for several hours.

A separate process is the cultivation of fluff to the consistency of milk of lime. After receiving calcium hydroxide by mixing an equal amount of lime and water, the substance is left for a while to dry. Then the resulting composition must be diluted with 9 liters of water. Ready milk of lime is a 10% lime mixture.

If you decide to whitewash the walls with quicklime at home, consider the method of obtaining the composition. If you made the mixture not using a special hydrator-separator, but manually, then you must thoroughly mix the solution immediately before the whitewash. Applying the composition to the ceiling and walls by using a large brush. The procedure starts from the left corner of the window. It is important to try to apply the solution without gaps, but in any case it is better to apply several layers of the substance.

If lime composition is used for whitewashing trees, you need to follow a certain sequence of actions.

• A bucket of about 10 liters should be filled with water.
• A couple of kilograms of fur must be diluted with 1.5 kilograms of clay and 300 grams of copper sulphate are added to the solution.
• Then it is necessary to thoroughly mix all the components in water to obtain the finished composition with the consistency of sour cream.
• The resulting solution is applied to a tree trunk. Do not scoop too much to avoid smudges. The finished layer should not exceed a thickness of 4 millimeters.

Inexperienced builders do not always use the composition of hydrated lime correctly. To learn how to apply calcium hydroxide, protect your health and get an effective result, need to listen to certain recommendations.

• If you decide to treat the country greenhouse with quicklime, apply the substance both inside and outside the building to provide reliable protection against pests.
• Do not add a ready-made mortar to a fresh mix, for example, concrete. It must take some time for all the powder particles to acquire a uniform consistency.If you add the finished solution ahead of time, the quality and consistency of the final mixture will significantly deteriorate.

• When using hydrated lime to rid the soil of acidity, you need to correctly calculate the amount of the composition. It is determined by the level of acidity. Only by measuring this level with the help of special pH instruments, you can understand how much calcium hydroxide you need.
• For processing of country tools, only freshly calcareous limestone is suitable.
• If the hydrated solution gets on the skin, it is necessary to remove the composition with a cotton pad soaked in vegetable oil. After that, make a gauze compress, which must be moistened in a five percent acetic essence.

• If you are going to make a solution based on lime, you can gradually add pre-sifted sand to the paste composition. After kneading, strain the prepared solution through a special sieve, thereby improving its uniformity.
• To speed up the setting of the composition, add a plaster to it. Thanks to this material, the lime mortar will set in less than 5 minutes.

• Slaked lime can be stored for various periods of time. The specific period determines the solution in which it is included. Storing the plaster with the addition of sodium hydroxide is about a month, while the mortar can be stored for no more than two weeks. If lime is planned to be stored in the winter period, it is necessary to protect it from freezing. You can even bury the containers with the composition in the ground, but the depth of the pit should be at least 70 centimeters. If you have materials for thermal insulation, they will also be useful for the storage of hydrated lime.
• If you plant lime yourself, it is important that the process takes place outdoors. Remember that lime fumes are quite toxic and can be dangerous to your health.

• When you first use a solution of slaked lime, which you have made yourself, most likely you will have small calcareous lumps. Do not immediately get rid of them, you can find them re-use, soak them with water.
• Pay attention to the consistency of the lime mortar immediately before application. Sometimes this composition needs to be diluted.

Hydrated lime is a truly necessary and useful material.

See the following video for the production of slaked lime.