Quicklime, also known as calcium oxide (CaO), is a caustic alkaline substance. It has been used for centuries for many purposes: as a mortar, flux, for processing grain and to create a waterproof lubricant for boats. Quicklime was also used as fuel for cooking and heating water. Today, quicklime is used in many industrial processes. Thus, there are many reasons why you might need to obtain this substance. Fortunately, cheap and widespread materials are used to produce quicklime. With little effort, you can get quicklime at home.
How to extinguish lime?
Before starting construction work, lump lime must be properly extinguished. The end result of this reaction will be fluff lime of a certain consistency.
How to extinguish lime for whitewashing walls:
- Wear protective clothing, gloves, a respirator and goggles.
- Pour lumpy raw materials into a stainless steel container.
- Pour with cold water, a ratio of 1: 1. A chemical reaction will occur with a temperature spike of more than 100 degrees, boiling and spraying.
- In time, the reaction passes in half an hour. Then the solution is well mixed with a stick of wood - until a homogeneous mass. After 30 minutes, when the violent reaction was over and everything was stirred, the solution was left for a day to ripen, stirring occasionally.
- The whole process takes place in the fresh air or in a ventilated area.
The resulting composition is used for any purpose. If you add a little water to it, you get a lime dough, it looks like sour cream. Add even more water - milk of lime. The intensity of the applied whitewash layer depends on the consistency of lime.
How and in what proportions to extinguish lime?
There are several ways to extinguish lime. The main thing is to do it right, otherwise the quality of the final product will suffer.
Lime is divided into three groups:
- quickly extinguished - up to 10 min., fill half of the tank with lime, add water to the top. Gently mix, while adding water in small portions. At the end, pour into another container,
- medium quenching - up to 20 min., the whole process as in the first case. The proportion of lime to water is 1: 1, but no more water is added,
- it is slowly extinguished - more than 25 minutes, a little more than half of the capacity is filled with quicklime, water is poured into a thin stream. If the stones begin to crack, then quenching has begun. Water is added in small portions until a lime dough is obtained.
After a chemical reaction, not all pieces decompose, in which case they are discarded. There is another important point: after the lime is extinguished, it is necessary to mature in a cool and dark place for 3 weeks, then whitewashing will be ideal.
- It is customary to call lime materials after firing and a special technology for processing such natural materials as chalk, limestone, limestone and other carbonate rocks. Thermally processed in furnaces of various types at +1000 - 1200 degrees blocks of rock turn into pieces of various shapes.
- For further use, they undergo special processing without any chemical components and catalysts. Therefore, 100% natural material is obtained, in which a small content of mineral additives and clay impurities is allowed.
- More often lime is used in construction. And not only. Special brands of lime are widely used in the iron and steel industry, food, pulp and paper, leather, chemical, textile and sugar industries. Also, agricultural workers and environmentalists use lime to neutralize flue gases or water effluents.
The popularity of lime
The story did not preserve the name of the one who first thought of using the unique capabilities of lime. It is possible that this was one of the first finishing materials for decorating the homes of our ancestors. Obtaining patents and copyrights for innovations appeared at the time of modern history. Now he would be among the richest oligarchs in the world.
Indeed, according to experts, about 300 million tons of lime are produced annually in the world. Of these, 120 million tons are sold on the market. Russia is among the leaders in the production of this finishing material. About 10 million tons of lime are produced annually in the country. Of these, 4 million tons for construction.
- Longer than all decorative materials and more often lime is used for whitewashing. Using it does not require special skills and physical effort. It is reliable and not too burdensome for a family wallet.
- Whitewashing with a mortar of lime of wooden structures or walls of houses is a tool that has been used and tested for centuries. It was made not only for decorative purposes, but also to prevent rotting wood, fire protection.
- Today in megacities practically no one covers the walls of rooms with lime. However, in the rural outback they still prefer to use it to cover hidden beams, invisible rafters or internal runs.
Varieties of lime
Silicates give lime hydraulic properties. Depending on the degree of their content, lime is considered to be air or hydraulic. Hydraulic lime has the ability to enhance the solidification process and preserve the strength of solutions in air and in the aquatic environment. Depending on the content of clinker minerals, it can be weakly hydraulic or highly hydraulic.
Air lime is designed to ensure the hardening of mortars used in the construction and preservation of their strength at a normal level of humidity.
According to the level of oxide content, there are:
By type of processing, lime happens:
- lumpy, the so-called boil,
- ground in the form of a powder obtained by grinding burnt lumps,
- fluff, which is a slaked material obtained after quenching lumps of water,
- lime test - a product of quenching lumpy raw materials,
- milk of lime - white suspension.
In addition, lime is divided into:
- quickly extinguished in no more than 8 minutes,
- extinguishing medium - in no more than 25 minutes,
- extinguish slowly for at least 25 minutes.
Powdered lime is available with or without additives. The most famous species is quicklime. It is widely used in the manufacture of concrete, construction, finishing, binding and antiseptic solutions. With its help, an artificial stone is produced.
Using different technological parameters of rock firing, lumps of lime with different degrees of strength are obtained:
- firmly burned
- softly burned
- intermediate option.
As a material for construction work, softly burnt lime, in which:
- smallest grain size
- lower density
- minimum blanking time.
During the quenching process, heat is generated. If safety precautions are not followed, there is a risk of severe burns.
From the certificate of compliance with the quality of lime, you can learn about the grade and condition of lime, the percentage of impurities. This document is issued only to organizations that comply with GOST in the manufacture of the material.
What is lime made of?
The type and brand of lime determines the main scope of its use.
- Lime for construction work made from rocks containing a large percentage of calcium and magnesium. It is used as a plasticizer in concrete mixes and binding solutions. This brand is sold in lime test or in lumps and fluff.
- For the manufacture of hydraulic lime by firing limestones with 6-20% clay impurities are used. This brand is used to produce concrete of low types, because it has low ductility, in contrast to a high level of strength. Hydraulic lime is often used in the construction of structures that will be operated in conditions of high humidity.
- Lump lime used as a semi-finished product for the preparation of powders or solutions. Store it in closed warehouses to protect it from moisture. It is most often implemented for the preparation of whitewash solutions.
- Garden lime used to enrich calcium acidic soil. Without enough of it, plants grow and develop poorly. Slaked and quicklime are added to the soil in rainy spring or autumn weather. Precipitation contributes to a better dissolution of limestone.
- Porous white mass soda lime is caustic soda mixed with slaked lime. Another area of application is the production of gas masks and pressure chambers, equipment for divers.
- Composed of bleach free chlorine and calcium hydroxide. It has a powerful disinfecting power and whitening property.
- Low cost. In the rating of materials, lime in lumps is rated rather high. To find material for finishing work with the same combination of price - quality is almost impossible.
- Disinfection. Bacteria that get on the film formed by lime die.
- Moisture resistant.
- No bad smell.
- Versatility. Possibility of use, both on the old whitewash, and on new surfaces.
- UV resistance.
- Friendly to dyes.
Two main disadvantages of lime:
- Risk of occurrencestreaks and stripes, bubblesif the rules for the percentage of preparation of a solution for whitewashing or concrete are not observed. A very liquid consistency will not stain the surface to the required saturation, and a thick whitewash solution, when dried, will turn into bubbles and crumble.
- Caution is required during lime handling..
Lime for whitewashing is used on facades after plastering, the surfaces of walls and ceilings in basements and rooms with high humidity or dry, kitchens, toilets. The calcareous composition is persistently indifferent to the influence of water and temperature changes. For example, ceilings are bleached with milk of lime, and even walls after plastering are painted with lime-based paints.
- Lime is used for priming solutions and water-based paints for finishing surfaces inside and out, not only as a paint, but also as a bonding element. However, for tinting calcareous mixtures with an alkaline nature, only alkali-resistant pigments are used. For example, for 1 kg of lime no more than 100 g of carbon black or chromium oxide, mummy or umber is added. These colorants are diluted with water to a thick porridge. After 5 hours of exposure, stirring vigorously, color is added to the fluff, which is diluted to the consistency of milk.
- Buy rationally dry lime. It persists for a long time. Preparation for use does not take much time.
- Before breeding lime, large lumps need to be crushed and extinguished. Depending on how the solution will be used, a fluff (powder solution) or dough is prepared. To do this, you need to take a different amount of liquid.
- To prepare a fluff pad for whitewashing a surface with an area of 2.5 squares, you need to take a fairly deep container without necessarily rust. This is necessary, because during the extinguishing of lime with water, the volume increases by 2-3 times.
- Put in a bowl 1 kg of lime lumps. Pour 0.75 - 1 liter of cool water. Cover lightly so that steam remains open. If you take a little water to extinguish lime, it can “burn out”. If there is too much water, clumps of lime can “suffocate”.
- The procedure should be carried out with extreme caution, because the solution heats up to about 140-150 degrees. The boiling mixture hisses and splashes, so it is better to play it safe and put on safety glasses and gloves before extinguishing lime.
- Within 8-30 minutes of boiling should be thoroughly mixed seething mass with a wooden stick.
- When the extinguishing process is completed, you must close the container with a lid and put it in the cellar for 15-30 days. Only after such exposure does the material acquire the most effective, disinfecting and reliable properties.
- On the day of whitewashing, you need to dilute the fluff with water. Whitewashing of walls or ceilings is done with milk of lime obtained from thorough mixing of 3 parts of water with 1 part of freshly slaked lime. The liquid should be added so much so that on a stick that mixes the solution, lime remains perfectly white in the form of a dense and even film.
- For the preparation of lime test, the algorithm of work will be the same. In addition to the amount of fluid that will require significantly less.
Five tips from lime professionals
- To increase the strength of the coating and prevent swelling of the plaster layer, 10-15% of paint with a latex base or wallpaper glue is added to the milk of lime.
- For a more dense adherence of lime milk solution to ½ bucket of whitewash solution is added green soap (1 tablespoon).
- To give decorative whitewash additional durability, drying oil (1/3 of a full tablespoon) and table salt (about 5 g) are added to this volume. Everything is thoroughly mixed, and then filtered through a fine sieve to remove undissolved lumps and grains.
- A light bluish tint that favorably shades the surface of the ceiling in daylight can be obtained by adding blue (20 g).
- Painting with lime coloring compounds should be carried out on cold or wet days.
- Whitewashing the surface of walls, ceilings or other structures of a building is considered the most inexpensive finish. Consumption depends on the selected application technology and surface smoothness. Using a brush requires more whitewashing. On perfectly aligned walls, less milk of lime will be consumed than on painting brick surfaces. Approximate consumption per 1 m² of flat walls - 0.5 l of ready-made solution for whitewashing.
- Typically, professional masters whitewash 1 m2 of walls with one layer is estimated at 50 rubles and above. The price depends on the need for cleaning from dirt or paint, surface structure, number of layers.
Lime consumption during whitewashing
The cost of using lime is more profitable than painting walls with water-based paints or decorating with other materials. And in terms of quality characteristics and antiseptic properties, it surpasses many of them.
How to extinguish lime: a consistent process instruction. How to extinguish lime at home - recommendations from A to Z
How to extinguish lime
The principle of making slaked lime is quite simple, which explains the low cost of the final product. However, the process itself requires taking into account many specific nuances, the presence of experience and knowledge.
Key points to pay attention to:
- choice of extinguishing methods,
- quality, fraction and grade of raw materials,
- proportions of lime, additives and water,
- hydration site
- necessary inventory and equipment,
- safety precautions and protective measures,
- preparation of tanks for extinguishing,
- maintaining a stable temperature,
- procedure time
- type of packaging and method of storage of the product.
To the question of how to extinguish quicklime, experts give an unambiguous answer - in production, where there are all conditions necessary for hydration. However, lime can be extinguished at the construction site, in the garden or at home with proper preparation.
Why put out lime: general information, concepts and benefits
Slaked lime (fluff) is in demand in many areas and areas:
- construction and repair,
- livestock farming
- laboratory tests
- citywide needs
- pulp and paper, chemical and food industries,
- leather industry
- metallurgy, etc.
Hydrated lime is an excellent binder for masonry and plaster mortars. In quick condition, it does not provide the necessary plasticity of building materials. Having passed the quenching procedure, the substance gains water resistance, accelerates hardening and facilitates the application of building mixtures.
Quicklime and the process of extinguishing it pose a threat to human health. The interaction of calcium oxide and water is characterized by a violent reaction: a lot of heat is released, water boils, and the mixture begins to spray in all directions.
Before extinguishing lime, it is necessary to protect the skin, mucous membranes of the eyes and mouth, and protect the respiratory tract. To avoid burns, wear goggles, goggles, rubber gloves and long-sleeved clothing.
Do not carry out the procedure in a room with closed windows and a door. If it is not possible to check the room, it is worth using a respirator or gauze bandage. In order not to burn yourself with steam, it is best not to bend over the container.
Lime extinguishing instruction for construction work
For construction use fluff, lime dough or milk of lime. The result of the quenching depends on the ratio of lime and water, the grade of lime and the aging time of the finished mixture.
Step-by-step instructions for extinguishing lime at home:
- Take a clean plastic container or pan.
- The tank is filled with lime.
- In a ratio of 1: 1, clean tap water is taken.
- Water is poured into the container in small portions.
- Когда кипение приостанавливается раствор нужно размешать.
- По окончанию реакции смесь размешивается до однородного состояния.
Разводить известь следует при помощи деревянной лопатки. Hydration can take anywhere from 30 minutes to an hour. As soon as the little fluff is ready, it needs to be infused in a cool dark place. The mortar for plaster can withstand a month, for masonry - two to three weeks.
How to extinguish lime for whitewashing walls
It is recommended to whitewash the walls of garages, basements, chicken coops and other premises with solutions with the so-called lime test. The procedure for preparing the dough is similar to the recipe for traditional fluff. The only difference is the proportions - only 40% of water is required for one part of lump lime.
If hydration is carried out correctly, stains or bubbles will not appear on the treated surface, the mixture will go to bed much more evenly and will be resistant to moisture.
Tip : In order for the chemical quenching reaction to proceed evenly, water should be added in small trickles using a kettle or garden watering can. After an hour, the lime dough is also left for at least two weeks in a dark room.
How to put out lime for whitewashing trees and bushes
To prepare a 20% mortar, mix one bucket of slaked lime with two buckets of clean water. For a 10% solution, you will need four buckets. A small amount of white clay can enhance the protective properties of the mixture.
For coloring the tree trunks, the solution does not need to be insisted for weeks - they are extinguished a couple of hours before the start of work. If you plan to whitewash using a spray gun, first thoroughly strain the milk of lime through a fine sieve.
Lime extinguishing for soil
Liming soil with slaked lime allows to achieve the following results:
- the acid-base balance of the soil is restored,
- microorganisms useful for vegetation are activated,
- the soil is enriched with calcium,
- soil structure and water permeability improves,
- increases the effectiveness of other fertilizers.
To turn quicklime into fluff per 100 kg of substance, 3-4 liters of water will be required. Slaked lime powder will be ready for use after 10-20 minutes.
The powdery powder is best suited for liming and can be easily distributed in the desired proportions on the plot. Quicklime is unsafe for plants and harder to apply to the soil.
How long is lime extinguished
Conditionally, lime is divided into three groups, based on its class and rate of extinction:
- quick-extinguishing (5-10 min),
- medium quenching (15-20 min),
- slow extinguishing (more than 25 min).
Water is added to quick-acting lime immediately. It is necessary to maintain uniformity of the mixture throughout the procedure, adding a little more water if necessary. Stirring begins with the appearance of steam and the first cracks in the lump of lime.
Extinguishing lime is a simple process, quite affordable both at the construction site and at home. Depending on the starting product, lime may be:
- Quick blanking (the whole process takes no more than 8-10 minutes)
- Medium blanking (extinguished in 15-20 minutes)
- Slow blanking (full process takes more than half an hour)
The quenching time is calculated from the time the water was poured into the tank and until the temperature of the mixture stabilized. Regardless of the type of lime chosen, the entire quenching process continues for a couple of days after the active phase.
Preparation for slaking lime
Before you begin the process itself, you should prepare yourself and the source material. To protect the eyes, respiratory system and skin of the hands you will need protective glasses, a respirator and mittens. Thick clothes that protect the body from splashes will also be useful.
As the starting material, quicklime, water, a quench tank and a strong stick for mixing the mixture should be prepared. The container should be metal or wooden, and in no case plastic - it will not withstand heating to 150 degrees, and it is this temperature that the mixture reaches when extinguishing. If we are talking about a large amount of lime, then it is necessary to prepare a wooden box and a pit of the appropriate size to drain the mixture. The box should be equipped with a drain window with a mesh for filtering.
How to extinguish lime
To get a good quality calcareous material, you must do the following:
- First pour prepared lime into the container, which is usually sold in lumps or in powder.
- There, pour water in an amount of 1 liter per 1 kg of lime. With this proportion, it will be called so-called fluff lime - a fine white powder used in construction. Water should be poured a little, watching the quenching process. If you take 0.4 liters of water per kilogram of starting material, the slaked lime will be called dough and the consistency is like sour cream.
- It is important to stir the mixture with a stick every time the steam ceases to stand out, and until the reaction stops completely.
For slowly extinguishing lime, water must be added little by little and completely poured out when the clods completely disintegrate.
For quick and medium quenching lime, it is important to give water until the formation of steam stops. At the end of the reaction, the container with milk of lime should be set aside for 36 hours to insist and thicken. You can use cooked lime only after a month.
Box blanking features
If the lime was extinguished in a wooden box, then at the end of the reaction and steam evolution it was poured through a window into a prepared hole, which was then closed with planks for a couple of days for infusion. After a two-day period, lime is covered with a layer of sand in 20 centimeters for another two weeks-a month. It is better to start making lime with this method in the fall and, having covered it for the winter from frost, use it in the spring. You need to know that it can never be old - with time, the properties of lime only improve.
Buying a finished garden whitewash for trees is expensive, we have learned this from our own experience. In addition, it contains the same lime plus a small amount of binder components. Garden whitewash and lime-fluff have a big minus in that solutions based on them are quickly washed off from trees. Experienced gardeners and authors of gardening reference books recommend using quicklime. Solutions based on it are more dense and stable.
Also, to increase the viscosity of the solution, casein or wood glue, clay is added to it. And as fungicide - copper sulfate. This was discussed in a previous article:
Many do not know how to extinguish lime for whitewashing trees in what proportions to breed in water ... Honestly, we did not know either and did not try to extinguish ourselves. Therefore, they turned to reference books, videos and read the instructions for use on the packaging. Next autumn or next spring, we’ll definitely prepare a solution for whitewashing trees already from quicklime and lay out a photo report on what happened (this year everyone has whitewashed garden whitewash). In the meantime, share information:
Source of information: youtube video
- Pour a bag of lime weighing 3 kg into a bucket (metal or enameled), pour 8-10 liters of water, mix. Lime begins to “boil”, so the bucket heats up. You need to wait 40-60 minutes for the heating and quenching process to stop. Once the bucket has cooled, you can use lime to whitewash, and also add various additives to it: vitriol, mullein, clay or glue.
Source: instructions for quicklime packaging
- Pour lime into a clean enameled container and add the required amount of water. Wait until the lime is completely extinguished (2-3 hours). It is important to observe safety precautions and work while observing personal protective equipment.
- According to another instruction, pour 3 kg of quicklime into a 10-liter metal bucket and pour 4 liters of water. Extinguishing time: 24 hours. Then the prepared lime dough is diluted with water to obtain the desired consistency.
The last instruction seems more sensible to us, because as a result of quenching, a very concentrated and thick solution is obtained. It will be difficult to whiten trees with such a composition, so it is best to dilute it with water to the desired consistency.
To know what you’re going to, here’s a video that shows how the process of extinguishing lime occurs. Lime boils, boils, therefore use protective equipment (gloves, masks) is a must.
It is also used in quicklime, for example, as a reinforcing and astringent material. If you extinguish it, then the plaster will be much more durable on the base, and the solution becomes more plastic when it is added.
Slaking lime It is produced very often, since it is in this state that the material is used in most cases. For example, it is used for whitewashing rooms, as well as wooden fences and rafters. This procedure protects the wood from rotting and burning.
You can also use the material for construction masonry, silicate concrete. Also, this material is taken in the manufacture of bleach, softening water, in the production of fertilizers. You can also use lime in the process of tanning the skin, in the food industry, in dentistry.
Extinguishing lime - principle of operation and safety
It should be noted that the extinguishing of lime at home is not a difficult process, especially since it does not need a lot of time or materials, and there is no need for any special equipment.
At construction enterprises, a pit for extinguishing lime is often found. Quicklime powder is poured into this pit and poured with water in a certain proportion. It all depends on how thick the mass should be (thick material or in the form of milk).
Before extinguishing lime, you need to know that the extinguishing period is 24 hours. However, for greater efficiency, it is recommended to withstand the process up to 36 hours. To dilute the mixture, it is necessary to prepare a capacity for extinguishing, lime, water and a stick for stirring.
Naturally, you need to work with gloves, glasses, a respirator, a tarpaulin suit and make sure that the mixture does not fall on exposed skin, as it can corrode the skin and cause irreparable harm.