Construction lime production. Own lime production. Scope of application of lime and chalk
State of the art production of hydrated lime in Russia.
In Russia today, the production of hydrated lime is no more than 5% of the total volume of lime. According to various sources, it produces about 11 million tons of domestic lime per year. Of these, hydration accounts for a little more than 100 thousand tons.
No more than a dozen of its manufacturers are known:
1. "Ekstor", Vidnoe settlement, Moscow region. (15000 ... 18000t / year)
2. "Uglovsky lime plant", the village of Uglovka, Novgorod region. (20,000 ... 24,000 t / year)
3. "KOA-GAZ" settlement Kraskovo, Moscow region (10000 ... 12000 t / year)
4. "Uralizvest", Yekaterinburg (10000 ... 12000 t / year)
5. "Lime Production Plant", Melikhovo, Vladimir region (5000 ... 6000t / year)
6. "Yeletsizvest", Yelets, Lipetsk region (5000 ... 6000t / year)
7. "Oskol Metallurgical Plant", Art. Oskol, Belgorod region (5000 ... 6000 t / year)
8. "Kopanischensky combine building materials", Kopanische, Voronezh region. (2000 t / year)
Table # 1. Hydrated lime producers
Name | Packing | Shipment | Price | Month volume | ||||
| bags | MKR | in bulk | covered | gondola car | auto | |||
| "Eletsizvest" | b / m 20 kg | No | No | Bags with e / cart manually | No | Bags, in bulk | 4012,00 | 2nd grade ~ 500t |
| "KOA-GAZ" | b / m 20kg | No | auto | Railway container | auto | Bags, in bulk | 4500,00 4000,00 | 2nd grade ~ 1000 t |
| "Uralizvest" | p / p bags with incl. 20 Kg | MKP with incl. 500 kg | There are plans for a car and a railway carriage | Covered on pallets and without | FIBC without canopy | Bags, MKP | 5000,00 4800,00 | 1st grade ~ 1000 t |
| "Zabudovo" | b / m 20 kg | MKP with incl. 1000 kg | auto | Bags with e / cart manually | No | FIBC and b / m in bulk | $ 96.00 $ 65.00 | 2nd grade |
| "Uglovsky lime combine " | p / p bags 25 kg (Iran) | MKP with incl. 500 Kg | Auto, "hopper" | Bags from the conveyor in manual and e / car on pallets | MKR in 3 rows without canopy | Bags, in bulk, MKP | Single price 4366,00 | 1st grade |
| "Krasnoselskstroy-materials" | b / m 25 kg | MKP with incl. 500 kg | auto | Bags from the conveyor for manual and e / car for pallets | No | Bags, in bulk, MKP | 2nd grade | |
| Extra | b / m 20 kg | No | auto | Bags with e / cart manually | No | Bags, in bulk | 4602,00 4053,00 | 1st grade ~ 1500t |
| OskolskyElectrometal- lurgiccombine " | No | MKP with incl. 500 kg | auto | No | FIBC without canopy | MKR, in bulk | 4500,00 | 1 grade ~ 500t |
| "Lime production plant" (Melikhovo) | b / m 20kg | MKP with incl. 350 kg | auto | Bags from the conveyor in manual and e / car on pallets | MKR covering with a canopy | Bags, in bulk | 4345,00 3520,00 | 2nd grade |
| "Kopanischensky KSM" | p / p bags with incl. 35- 40 kg | No | No | Pusher bags e / cart | No | bags | 2500,00 | 2nd grade ~ 300t |
Perhaps there are still manufacturers, but most of them produce only for their own needs or not. a large number(as, for example, the Combine of Concrete Products in the Leningrad Region, 2-3 thousand tons / year).
In addition, a part of the product is imported to the Russian market by Belarusian producers:
1. "Krasnoselskstroymaterialy", Grodno region.
2. "Zabudovo", Minsk region.
The listed enterprises are currently the main producers of hydrated lime for the domestic domestic market.
In the summer of this year, the production of hydrated lime "Pridonkhimstroy Izvest" began in the city of Rossosh, Voronezh region. The production capacity of the line mounted on imported equipment from Pfeiffer AG (Germany) is at least 30 thousand tons / year of high-quality hydrated lime product.
Table 2. Characteristics of hydrated lime produced by Pridonkhimstroy Izvest
Indicator name | Product indicators |
| Active CaO + MgO | 71,0 % |
| CO 2 | 3,0 % |
| Humidity | 0,5 % |
| Ca (OH) 2 | 94,0 % |
| Bulk bulk weight | 0,340 |
| Dispersion: sieve No. 0.2 | 100 % |
| Dispersion: sieve No. 0.08 | 99,6 % |
| Moisture retention capacity | High |
| Specific surface area | More than 30,000 cm 2 / g |
They plan to establish the production of hydrated lime:
1. "Soligalichsky lime plant", settlement Turovka, Kostroma region.
2. "Building materials", Belgorod, Belgorod region.
In addition, at the new lime production plants under construction, it is also planned to produce hydrated lime that meets the highest requirements. In particular:
1. "Eldako", settlement Selyavnoe, Voronezh region. (2008),
2. "Fels Lime", Tovarkovo settlement, Kaluga region. (2009),
3. "Lhoict Russia", Ryazan region. (2010).
It can be assumed that the plans of the Nord-Kalk Oy company, which acquired the Alekseevsky lime plant in the Leningrad region, also include the production of this product.
Thus, by 2010, its output can double, and the quality - significantly increase. The fact is that the production facilities being created use advanced imported technologies, equipment and the best raw materials.
Such a prospect cannot but rejoice the producers of dry building mixtures (CCM), since they consume more than 50% of the produced hydrated lime.
Diagram # 1
~ 17% purchase concrete plants,
~ 15% builders (for the preparation of various solutions),
~ 9% road builders,
The rest is chemists, agriculture, water treatment, etc.
Hydrated lime is one of the additional components for the production of some types of dry mixes, and the best known mineral component, which gives the mixtures high plasticity and high water-retaining properties. It provides high adhesion of mortars to mineral (concrete, brick) and some non-mineral substrates (metal, wood). In addition, it is an environmentally friendly, “living” product, which is important in the increasingly stringent environmental requirements for construction.
Consumer requirements
The bulk of consumers in their requirements does not go beyond compliance with the requirements of GOST. If we focus on the requirements of GOST, it turns out that almost all hydrated lime produced by the above manufacturers meets the requirements of grade 1, even if it is made from quicklime of the third grade. These are our standards!
It seems that consumers are not very interested in getting better quality lime.
Lime over High Quality can lead to a change in the recipe, and even the production technology of some dry mixes.
Of course, the proportion of hydrated lime in the dry mix is not large, but still do not forget that "a fly in the ointment spoils the barrel of honey." In the face of growing competition, any little thing can become a determining factor.
Table No. 3. Requirements for "air" lime.
Indicator name | Rate for lime,%, by weight | |||||||
| Quicklime | Hydrated | |||||||
| Calcium | Magnesian and dolomite | |||||||
| Variety | ||||||||
| 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | |
| Active | ||||||||
| CaO + MgO, not less: | ||||||||
| without additives | 90 | 80 | 70 | 85 | 75 | 65 | 67 | 60 |
| with additives | 65 | 55 | - | 60 | 50 | - | 50 | 40 |
| ActiveMgO, | 5 | 5 | 5 | 20 (40) | 20 (40) | 20 (40) | - | - |
| no more | ||||||||
| Co 2, no more: | ||||||||
| without additives | 3 | 5 | 7 | 5 | 8 | 11 | 3 | 5 |
| with additives | 4 | 6 | - | 6 | 9 | - | 2 | 4 |
| unredeemed | 7 | 11 | 14 | 10 | 15 | 20 | - | - |
| grain, no more | ||||||||
The main requirements for the quality of hydrated lime of the 1st grade in accordance with GOST 9179-77, introduced in 1979 (as amended in 1989):
- active CaO + MgO not less than 67%
- the content of active MgO is not more than 2..3%
- humidity no more than 5%
Naturally, for the producers of dry mixes, the compliance of the product with these indicators is not enough. The important characteristics are:
- dispersion;
- the content of non-extinguished grains of calcium and magnesium oxides;
Interesting is the experience of the Oskol Electrometallurgical Plant and Bashneftekhim JSC, which have developed, agreed and approved their Technical conditions for hydrated lime intended for use in the petrochemical industry in the manufacture of additives and lubricants.
Table 5. (Extract from TU 2611-094-00187895-2000)
In terms of physical and chemical parameters, hydrated lime must comply with the standards specified in table No. 5:
Indicator name | Meaning |
| Mass fraction of active calcium oxide,%, not less | 70,0 |
| Decrease in mass during calcination at 1000 0 С (total mass fraction of hydration water and carbon dioxide),%, not more | 27,0 |
| Mass fraction of magnesium oxide,%, no more | 1,50 |
| Mass fraction of the residue insoluble in hydrochloric acid, %, no more | 0,70 |
| Total mass fraction of iron and aluminum sesquioxides,%, no more | 0,60 |
| Mass fraction of free moisture (105 0 С),%, no more | 0,50 |
| Mass fraction of the product passed ( wet method) through a sieve with a mesh:- No. 0315 K in accordance with GOST 6613,%, not less- No. 008 K in accordance with GOST 6613,%, not less | 95,0 92,0 |
Moreover, the technical specifications developed by them are even more stringent than the requirements of GOST 9179-77. The rules of acceptance, transportation and storage, packaging requirements are described in sufficient detail. Control methods, manufacturer's guarantees are prescribed.
The easiest way to solve this problem is to specify the requirements for the supplied products in the supply contracts.
Packaging and transportation problems
Getting high quality lime introduces another problem. It's a low problem bulk density
due to high dispersion and absence of impurities. The consequence of this will be an increase in transportation costs.
Equipment for obtaining such a level of product is quite expensive, as a rule, imported. Only fairly large enterprises that are firmly on their feet can afford it. Consequently, a limited number of enterprises will have the technology for the production of high-quality hydrated lime. Not everyone will be able to have such an enterprise close by. Therefore, the transport component will be quite high. Possible option The solution to this problem will be the installation of a technological line for hydration of quicklime, somewhere closer to large consumers, for example, in the Moscow region. Or, for example, the proposal of the director of "Spetspromtekh", Kotelnikov Yu.V., a rather authoritative specialist in matters of lime production. Mr. Kotelnikov proposes to compact lime or additionally mix it with fine weighting agents. On the one hand, of course, no one wants to pay for "ballast", on the other hand, one has to calculate. Perhaps the price of "ballast" will be less than the progressive scale of transport costs (I mean "overload-underload").
In addition, we encountered problems such as: packing
highly dispersed hydrated lime and quality
the packaging adapted for this.
When you look at how hydrated lime is packaged, the feeling that the best lime remains "overboard" does not leave. It seeps through any hole like air. She is air! That is, it is not enough to produce in accordance with the requirements that I mentioned above, you still need to pack, load and send. After all, in fact, you will have to load and carry air! Shipment by rail by her own a big problem... These are tariffs, underload (the volume is large, and the weight is small), various special conditions, monopoly, and finally, the elementary absence of enough normal, adapted wagons.
To solve all these problems, close interaction of science, design organizations, manufacturers and consumers, carrier companies, as well as industrial enterprises producing equipment is required. Naturally, close interaction with power structures, various industry associations and professional communities. The main thing is that the closest cooperation with the consumers of the manufactured product is necessary. We need the so-called Feedback... You need to know what the consumer needs today and what he will need tomorrow. And for this, I am sure, it is necessary to combine our efforts.
It is difficult to count on success without joining efforts. Therefore, in August last year, the Union of Lime Producers was created, of which I am the Executive Director, which united the main lime producers for the “open” market of the European part of Russia into a non-profit partnership. In the regions of the European part of Russia, and these are Central, North-West, Volga, Ural and South regions, there are more than 160 factories where lime is produced. Most of them produce lime for their own needs (metallurgists, sugar makers, chemists, some of the building materials factories). Only no more than three dozen enterprises operate on the "open" lime market, with a total production volume of more than 1.5 million tons per year. And the enterprises whose main activity is lime production is even less, a little more than two dozen. These are such as "Soligalichesky lime plant", "Lime production plant" in the Vladimirovsk region, Uglovsky lime plant "," Pridonkhimstroy Izvest "," Yeletsizvest "," Uralizvest "," Kopanischensky plant of building materials ", etc.
Today in the "Union":
1. "Uglovsky lime plant" Uglovka, Novgorod region;
2. "Building materials", Belgorod;
3. "Soligalichsky lime plant" Turovka, Kostroma region;
4. "Plant for the production of lime" Melekhovo, Vladimir region.
5. "Klintsovsky silicate plant" Chemernya, Bryansk region;
6. "Kopanischensky Combine of Building Materials"
Voronezh region;
7. "Eldako" Selyavnoe, Voronezh region. (plant under construction)
8. "Kovrovsky plant" Kovrov, Vladimir region.
9. "Lipetskstalproekt" Lipetsk ( project organization specializing in projects of furnaces and equipment for the production of lime)
10. "Pridonhistroi Lime" Rossosh, Voronezh region.
The members of the "Union of Lime Producers" account for a little more than 1.1 million tons, i.e. about 75%.
The purpose of creating our "Union" is clearly spelled out in clause 5.1 of the "Charter of a non-commercial partnership of lime producers" - "implementation of activities aimed at the formation of a civilized market of building materials and chemical products in Russia, its development and protection of the interests of suppliers and manufacturers, coordination of mutual efforts members of the Partnership to protect their rights and interests ... ".
R.F. Galiakhmetov, Director of the Union of Lime Producers,
Director of Pridonkhimstroyizvest LLC
Based on the materials of the conference report Baltimix-2007
Lime (giraldite, fluff, slaked lime) is obtained by firing limestone or chalk. It is made in rotary or shaft kilns. Depending on the composition of the raw material, it is calcium, magnesian and dolomite. The products are classified into three grades.
Firing takes place at a temperature of 1100-1200 ° C. The result of this procedure is complete removal carbon dioxide and the formation of calcium oxide, which is present in the composition of the product in the form of lumps different sizes... This type of lime is called quicklime. It is most often used in construction.
Lump lime is:
- fast-extinguishing (up to 8 minutes),
- medium damping (up to 25 minutes),
- slow-extinguishing (more than 25 minutes).
Klintsovskiy silicate plant produces quick-extinguishing lime.
Scope of application of lime and chalk
JSC "KSZ" produces quicklime lump and ground lime and dolomite flour (limestone). Due to its astringent property, the material is widely used in industry and the national economy. Quicklime is in demand in the following areas.
- production of building materials. In this area, lime is known as "fluff". It gives strength to silicate bricks, aerated concrete (gas silicate), dry building mixtures. Fluff is also used for facades,
- road construction. Giraldite (quicklime) is used to stabilize and improve the soil. The basis of the composition - calcium oxide removes water from the soil. This increases the stability and frost resistance of the soil. Giraldite is also used for the construction of all layers of the roadway,
- metallurgy. In this area, quicklime lump is used as a cleaning component, participates in the process of slagging and desulfation. It binds such impurities undesirable for steel as sulfur and phosphorus,
- chemical industry. In this industry, calcium carbide is obtained from lump lime, which is used for the synthesis of acetylene. Lump lime is also used for the production of soda. Lump type lime is also used for the synthesis of basic substances in organic chemistry,
- glass industry. Thanks to giraldite, in the process of melting the glass acquires hardness and density,
- pulp and paper industry. Giraldite is used in the production of wood fiber pulp,
- sugar industry. In this agricultural industry, quicklime is necessary to clarify and remove non-sugar from diffusion juice. Only a high quality product is used in the production of sugar,
- agriculture and forestry. V agriculture the product is used for liming acidic soils. Lime neutralizes harmful acids, helps to restore humus and healthy development plants,
- environmental protection. Lime production is also necessary for its use in air purification from industrial gases, neutralization of waste water and reduction of soil acidity.
The main areas of application of limestone flour:
- leaching of soils,
- fertilization of soils for growing many agricultural crops: carrots, beets, buckwheat, flax, potatoes, etc.,
enrichment of the soil with magnesium and calcium.
Technical characteristics of the materials produced
|
Qualitative indicators |
||||
| Content of active CaO + MgO | ||||
| MgO content | ||||
| CO 2 content | ||||
| Quenching time and temperature |
Lime is the generic name for products made from limestone. Technological and construction lime is isolated according to its intended purpose. The first is used for different types production: in metallurgy, chemical and Food Industry(added to sugar, disinfectants, paper, cellulose). Construction lime is used for whitewashing buildings, making lime mortars, etc.
By the amount of silicates and calcium aluminoferrites contained in lime, the following are distinguished:
- hydraulic lime. It contains clay and hardens from exposure to water. It is used for the preparation of cement mortars used for brickwork, etc.
- air lime - a product consisting mainly of limestone. It hardens in an air-dry environment.
According to its fractional composition, lime is divided into lumpy and powdery.
According to the method of further processing of raw materials, air lime is divided into freshly burnt quicklime and slaked lime. The latter happens different types, depending on the amount of added water:
- hydrated lime - fine powder with a low water content;
- lime milk (30-40% free water);
- lime dough (80% water).
Various types of slaked lime are used for the preparation of fertilizers, bleach, leather processing. Flour and lime powder are added to mixes for asphalt concrete, mixed feed, fertilizers.
We propose to open a business for the production of air lime of various types.
The technological process of lime production is not considered difficult, and the demand for it will not stop until they stop building and repairing buildings and roads.
Lime production technology
Various sedimentary rocks are used for raw materials: limestones (marble, dense fine-grained, oolitic), chalk, dolomites. Most often, dense limestones are used.
Lime production takes place in several stages. First, the raw material (fractions 0-300 mm) enters the receiving hopper of the apron feeder, which directs it to the crusher. After primary crushing, a belt conveyor transfers the raw materials to a vibrating screen, where limestone is sorted into fractions: 5-20 mm, 20-40 mm, and less than 5 mm. Raw materials of fine fraction (less than 5 mm) are sent for processing into lime flour. Lime of a coarse fraction enters the hopper, where the raw material is weighed. Next, the mixture of lime and fuel is heated and fed to the kiln. Usually, rotary or shaft kilns equipped with refrigerators are used.
The parameters of such a furnace are diameter - 2-3 m, length - 5 m, productivity depends on fuel: coal - 30, 50, 100 and 200 tons per day, natural gas - 200 tons per day, fuel oil - 150 tons per day. For the rotary kiln, fuel oil and gas are used as fuel. Parameters - length - 30-100 m, diameter 1.8-3 m, productivity - from 15 to 40 tons per hour. On the this moment Due to a number of advantages, shaft furnaces that run on gas or coal are most often used (easy to use, consumes little fuel and energy, and has the lowest cost).
After firing in a kiln, lime is cooled in refrigeration equipment from 1000 to 100-130 ° C. As a result, a well-known lumpy boil is obtained, which is further processed in two ways: it is ground in mills - as a result, ground quicklime is obtained, quenched in water - slaked lime comes out lime.
Extinguish lime different ways... For extinguishing in fluff, a hydrator of periodic or continuous action is used. Lime crushed to 3-5 mm is placed in a drum and quenched with steam. The blanking and unloading process takes 30-40 minutes. Lime is placed in a curing bin, where it continues to be slaked, which increases the quality of the product.
The quenching method in dough is rarely used due to its complexity. The boiling pot is crushed to 5 cm and quenched in the hopper for about 2 hours. In a quencher, lime is finally slaked with water heated to 40-50 C. On a vibrating screen, lime milk is sorted: large parts are separated. Then the milk goes into vats, where it settles. Excess water leaves through filters, resulting in a creamy product.
Equipment and raw materials (prices)
A lime production line looks something like this:
1. Preparatory department.
Vibrating feeder (10 thousand)
Jaw crusher (800 thousand-3 million)
Belt conveyor (about 200 thousand)
Sleeve filter (200-500 thousand)
Airlock (about 40 thousand)
Screw conveyor (about 70 thousand)
Chain elevator (180 thousand)
Sorting plant (about 800 thousand)
Silo (120-700 thousand)
Apron feeder (from 26 thousand to 1.2 million)
Dispenser (100-150 thousand)
Intermediate bunker (50-100 thousand)
Pressure filter (about 11 thousand rubles)
2. Firing department:
Chalk heater with chain drum drives
Shaft furnace (from 100 to 2 million)
Cyclone (10-100 thousand)
Smoke exhauster (40 thousand)
Gas burner (from 30 to 70 thousand)
Drum refrigerator (about 1 million)
Smoke exhauster
Screw conveyor
3. Warehouse for finished products:
Belt conveyor
Chain elevator
Silo of finished products
The total cost is 4.5-5 million rubles.
Limestone - about 250 rubles / ton (raw material costs - about 2 tons per ton of product; for a production of 50 tons per day, 2000 tons of raw materials will be required per month).
Coal - 1150-1500 rubles / ton (consumption - 150 kg per ton of raw materials).
Premises and staff
The limestone plant can be divided into the following parts:
- crushing section;
- raw mill section;
- mixing and storage section;
- section of a vertical shaft furnace;
- mill section;
- storage and packaging section.
The area of the premises is about 2000 sq. m. (rent - about 300 thousand rubles per month)
Energy consumption per ton of product is about 115-125 kW / h.
To organize the work of a plant with a capacity of 50 tons of quicklime per day, you will need next lineup workers:
Crushing department:
Crusher operator;
Transporter mechanic;
Elevator motorist;
Sorting department
Rumbling motorist;
Minder's assistant;
Transporter mechanic;
Elevator motorist;
Firing and cooling compartment
Shaft kiln roaster;
Conveyor mechanic;
Shaft furnace mechanic assistant;
Elevator motorist;
Pump operator;
Aspirator;
Conveyor driver;
Operator;
Locksmith on duty;
Electrician on duty;
Laboratory assistant;
Cleaners;
Taking into account the administration of the plant (managers, accountant), the total number of employees will be about 24 people. Fund wages a month - about 600 thousand rubles.
Storage and transportation requirements
According to GOST 9179-77, lump lime is shipped in bulk, powdery - in bulk or in paper bags in accordance with GOST 2226. It is allowed, with the consent of the consumer, to use four-layer paper bags. Lime is transported in any kind of covered transport. It should be stored and transported separately by type, avoiding exposure to moisture and contamination with foreign impurities. Guarantee period storage of lime - 30 days from the date of its shipment to the consumer. Quicklime with proper storage retains its properties for 15-18 days.
Safety requirements
Lime production is hazardous, therefore a number of rules must be followed. First, handle with care the kiln, which may cause industrial fire or burns. Avoid bringing your face close to the viewing window of the oven. Carbon monoxide, carbon dioxide can cause poisoning, therefore, raw materials are loaded only on special containers, the penetration of these substances into domestic premises should be prevented. Lime dust is harmful to mucous membranes and wet skin... To eliminate dust emissions, transport and bunkers should be closed with casings, covers, dust-removing devices should be installed, and dust hydraulic suppression should be applied. Conveyor belts should have shelters along their entire length and move at a speed not exceeding 1 m / s. Workers must wear respirators and special clothing.
Investment and return on investment
When producing 50 tons of lime per day, the initial investment will amount to about 6-7 million rubles. Monthly costs will be about 1.8 million. Product price: quicklime - 2,029 rubles / ton, slaked - 3,237 rubles / ton. The monthly profit is about 600-800 thousand rubles. The business will pay off in 8-12 months.
Demand and main consumers
When selling a product, it is important to know the main consumers. V in this case they are: construction companies (manufacturers of sand-lime bricks and aerated concrete, dry building mixtures), communal services and waste processing (in particular, gas treatment and water treatment).
Basically, factories that need technological lime produce it themselves. Therefore, it makes no sense to organize production with a large share of this type of lime, although it occupies about 85% of the market. According to research data, the share of quicklime in the structure of construction lime production in the Russian Federation in December 2011 amounted to 93.1%, which indicates a high demand for this product.
Cherukhina Christinaa
- portal of business plans and guides
Natalia Skorokhodova, Deputy General Director of the Company "Construction Information"
Slaked and quicklime (calcium hydroxide and oxide) is widely used in various industries. This article will focus on consumption of lime by the construction industry... Note that the bulk of this material is used by other industries.
Currently, Russia produces about 10 million tons of lime per year. Almost all of this is used in the form of quicklime (CaO). Hydrated, i.e. slaked lime (Ca (OH) 2), in 2004 no more than 100 thousand tons were produced. More accurate estimates can be made for the Central region of Russia, where the lime market was studied in detail by "Construction Information" in the fall of 2005. So, the total consumption of lime (quicklime and hydrated) in the region in 2004 amounted to 2600 thousand tons, the volume of use of hydrated lime - no more than 25-30 thousand tons.
The main consumers of quicklime are metallurgical plants and sugar factories. These enterprises, as a rule, provide themselves with lime on their own due to the peculiarities of the technological process. In metallurgy, very high demands are made on the quality of lime. Several days of storage of the calcined product can reduce the lime activity below the level required for steelmaking. That is why large metallurgical plants themselves are engaged in the production of lime. Only small-scale enterprises or producers of ferroalloys buy lime on the side, where lime is used in small volumes. In the production of sugar, not only lime itself is used, but also saturation gas (contains CO2), which is obtained in a lime-gas kiln during limestone roasting, which makes it necessary to install a kiln at the plant itself.
Figure 1 shows the share of various industries in the consumption of lime in the Central Region. In Russia as a whole, the share of lime consumption by metallurgical plants is noticeably higher, since the main steel production facilities are concentrated in the Urals, while only one of the largest enterprises, the Novolipetsk Metallurgical Plant, is located in the Central Region.
Manufacturers of building materials - silicate bricks and aerated concrete - make a significant contribution to the consumption of quicklime. Many sand-lime brick factories have their own lime production. As a rule, these are enterprises with a large Soviet past working for more than a dozen years. On the contrary, large recently established enterprises for the production of aerated concrete (aerated concrete / gas silicate) mainly buy lime. Immediately, we note active growth market of aerated concrete in the country. In the last two years, powerful plants have been built, such as LSR-Aerated Concrete in St. Petersburg, Teplit (Sverdlovsk Region), Aerobeton and XELLA (Moscow Region). The capacity of these enterprises is 300-600 thousand m3 of aerated concrete per year. According to our estimates, the potential of the aerated concrete market is much higher than the existing capacities (even taking into account the plants under construction). There are plans to build other new factories as well. This sub-industry will continue to develop intensively, therefore, the demand for lime will only grow. According to forecasts, by 2010 the consumption of lime by aerated concrete producers will double in comparison with 2005.
As for hydrated lime (fluff), the main consumers here are enterprises producing dry construction mixtures. Hydrated lime is the best known mineral component of dry building mixtures, which gives the mixtures high plasticity (workability, workability), high water-holding properties and also ensures high adhesion of solutions to mineral (concrete, brick) and some non-mineral substrates (metal, wood). However, lime is only one of the many components in mixtures. Figure 2 shows the structure of consumption of hydrated lime in Moscow. In Russia as a whole, the share of lime consumption by dry-mortar producers will be approximately the same 50%.
The segment of dry mortar producers demonstrates a steady growth in the production of mixtures, and, consequently, in the consumption of lime. Although the peak of the growth rates of dry mixes production is already behind, in 2005 the growth will amount to 20-25%, in the future - 10-15% per year. Accordingly, the consumption of lime by dry mixes producers will grow at a similar rate.
Hydrated lime is used as a mineral plasticizer and additive to reduce shrinkage (cracking) in cement mortars, as well as as the main binder in lime-sand plaster mortars. Plaster and masonry mortars can be prepared directly at the construction site or delivered from the mortar unit.
Not all concrete plants prepare masonry and plaster mortars with the addition of lime. these solutions are not in great demand. For example, in St. Petersburg, lime mortars are not produced by any concrete-mixing plant, and in Moscow such solutions are offered quite often, although they note a sharp decline in the production of these products.
Now let's see who supplies lime to the "open" market. Here we will not consider enterprises that produce lime only for their own use. Most large factories offering lime for sale in the European part of Russia - "Uglovsky lime plant" (Novgorod region), "Pridonkhimstroy Izvest" (Rossosh, Voronezh region), "Kopanischensky plant of building materials" (Voronezh region), "Soligalichsky lime plant" ... Lime (mainly hydrated) is exported to Russia by the Belarusian company Zabudova. Others import supplies no lime was noted.
The most popular among buyers are the corner and Rossosh lime. Moscow producers of dry mixes especially note the products of the Ekstor plant (Moscow), and in St. Petersburg hydrated lime is represented by the products of only two manufacturers - Uglovsky Klombinat and Zabudovy.
The lime market is growing slowly but steadily. Analysis of all consumer segments allows us to predict market growth by 3-5% annually. In particular, in the Central region, the expected increase in demand is not fully covered by the capabilities of existing and under construction enterprises, and in a few years a certain deficit in the supply of lime may form.
Lime is obtained by roasting calcium-magnesium rocks
(thermal removal of carbon dioxide) from chalk, dolomite, limestone, marl. When calcining limestone, the rock is decarbonized, that is, carbon dioxide is removed, while leaving significant pores and providing a weight loss of about 40% and a volume loss of up to 10%.
Lime production can be carried out in lime kilns in factories or in small quantities at home.
Lime production process in kilns
To obtain lime, there are several types of furnaces: floor, shaft, ring, rotating.
Gas-fired shaft furnaces are especially common in this industry due to the low cost of fuel and the small amount of fuel consumption.
The breeds from which the finished product are mined in quarries. Their dimensions are approximately 50-60 mm. For firing in shaft furnaces, smaller fractions are required, for which, before filling into the furnace, pieces of rock are crushed to required sizes... Then they are screened out on screens to ensure a uniform particle size distribution. After that, the prepared material is fired in furnaces at temperatures of 1050–1200 0 С, cooled. Thus, quicklime is obtained, which is a semi-finished product. In the future, it must either be ground or extinguished to obtain the final product (ground or slaked lime, respectively).
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For grinding lime, ball or vibration mills are mainly used. The finished product looks like a fine flour-like powder.
For extinguishing, drum hydrators are used, in which the extinguishing process takes place with the help of water or steam. V finished form slaked lime resembles dough.
The final product differs in the following ways:
- magnesian, gray with a magnesium oxide content of 5 to 20%;
- oily, perfect white, with a magnesium oxide content of 4%, sand and clay up to 5%;
- skinny yellow color, with a magnesium oxide content of 20 to 35%
Home production process
A much cheaper way is to produce lime at home. Considering this factor, this method can be put on a commercial basis and develop your own profitable business.
Lime is always in demand in construction, during repairs, for whitewashing ceilings and walls. The lime making process is not complicated.
This requires a room and a furnace in which the firing will be carried out. 
It is especially convenient to engage in the production of lime for those who live near the location of quarries and places of limestone deposits. The mined stones must be crushed to a size of no more than 2 cm in diameter. Large fractions split easily enough.
The furnace must be fired with coal, since only coal can give enough high fever for decarbonization. When firing with wood, it will be impossible to dial this temperature. 
With sufficient heating of the coals, spread on top of an even and not thick layer limestone, on top of which there should be another layer of hot coals. It is good to start such a process in the evening, then the lime will be ready by morning. Lime stones from the oven it is worth extinguishing in a bucket of water, lowering them for 10 minutes. Settled to the bottom white sediment- this is the finished product. It only remains to strain it through cheesecloth and then dry it. Having carried out several such cycles, it is possible to experimentally establish production and obtain a sufficiently high-quality product.
Thus, you can get lime, both for your own use, and for more mass production.
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