Lime is widely used in construction, including for the production of building materials. The raw materials for the manufacture of lime are sedimentary rocks: dolomite, chalk, limestone. After calcining these rocks over a fire, the calcium carbonate contained in them transforms into calcium oxide. When combined with water, a violent reaction occurs.
- - water,
- - sand,
- - lime,
- - shovel,
- - a wooden box with a fine mesh (cell 2x2 or 3x3 mm) with an opening with a shutter.
According to the slaking rate, lime is divided into three categories:
1. fast-extinguishing - extinguishing speed up to 10 minutes;
2. medium damping - damping speed from 10 to 30 minutes;
3. slow damping - damping speed over 30 minutes.
Lump lime slaked with a small amount of water (60-100% by weight) forms a dry fine powder - fluff. Lump lime, slaked with excess water, or fluff with the addition of water (1-1.5 parts per 1 part of lime) forms a lime dough - this is a mass of creamy consistency. Lime milk can be obtained by diluting the lime dough with water at the rate of 1 part fluff 3 parts water.
Lump lime can be extinguished dry. To do this, you need to lay lumps of lime in layers 20-25 cm high and sprinkle with water. There should not be little water, otherwise the lime will burn out, but it should not be too much, otherwise extinguishing will be disturbed. When the lime is mostly extinguished, it must be carefully collected in a heap and covered with a compacted layer of wet sand 5-10 cm thick, under which the lime is finally extinguished.
After 2-3 days, sand with lime is sieved through a fine sieve. If a large amount of lime is needed, then lump lime must be folded into a layer 20-25 cm high, poured with water and continue to fold and water until the pile reaches 1 m. Everything is covered with compacted wet sand. After a week, the lime will be extinguished and will be ready for use. Lime slaked in this way can only be used for mortar during masonry.
A creative pit is needed for slaking lime with a wet method. Having dug a hole, put a mortar trough near it - this is a wooden box with dimensions of about 1.5 by 2 m, in the lower part of which there is a hole closed with a fine mesh with a shutter.
Lump lime is put into the box at a height of ¼ of the side It needs to be poured with water, when it starts to fall apart into small pieces, add water and stir. After the lime has been slaked, stir it until thick milk of lime, remove the damper and drain the milk through a sieve into the pit. If a little water is added during slaking, then lime can burn, if there is too much water, it will "sink". In both the first and second cases, lime can no longer be used.
To avoid drying and coking, cover the lime porridge in the pit with a layer of clean sand about 10 cm thick.
To get 1 m³ of lime slurry, you need 3 m³ (30 hectoliters) of water and 400-440 kg of lump lime. For masonry, slaked lime is applied fresh (several days), and lime is added to the plaster mortar not earlier than 4 weeks, this is necessary so that the remaining sub-slaked particles do not begin to be extinguished in the plaster.
When laying, add 1 m³ of sand to 167 liters of lime slurry. When plastering, 200 liters of porridge are added to the lime mortar per 1 m³ of sand. To create 1 hectoliter of milk of lime required for whitewashing, you need 90-92 liters of water and 9-10 kg of lime.