Energy companies Krasnoyarsk Territory and the Republic of Khakassia, which are part of the Siberian Generating Company group, in 2013 sold and brought into economic circulation 662,023 thousand tons of ash and slag waste (ASW).

During the year, the Krasnoyarsk branch of SGC increased the volume of involvement of ASW in the economic turnover by 4% - from 637,848 thousand tons in 2012 to 662,023 thousand tons in 2013.

The growth in the economic turnover of ash and slag waste (a by-product of coal combustion at thermal power plants) allows reduce the load on the environment in the cities where the company operates. It should be noted that the main volume of ash and slag waste (625.5 thousand tons) in last year was aimed at implementing a major environmental project for the reclamation of ash dump No. 2 at Nazarovskaya GRES. The reclamation of an exhausted ash dump with an area of ​​160 hectares, located in the area of ​​the Chulym River, will allow these lands to be returned to economic circulation. For example, after a few there may appear green spaces.

In addition, the Krasnoyarsk branch of SGC continues to sell ash and slag waste to construction industry enterprises. The company started selling dry ash and slag for the first time in 2007. Then only 7 thousand tons of waste were sold. In 2013, sales volumes amounted to 36,525 thousand tons of ash and slag waste. Thus, the average annual volumes of ash and slag waste sales have increased over the 6 years of operation in this market more than five times. T This increase in demand indicates that builders highly appreciated this type of raw material. At the same time, ash and slag waste is bought not only by enterprises from the Krasnoyarsk Territory, but also from other regions of Russia.

Thanks to the active work of SGC in this direction, last year the volume of ASW sold and involved in the economic turnover (662,023 thousand tons) turned out to be 34% higher than the amount of ash and slag waste generated by the energy enterprises of the branch (495 thousand tons).

In 2014, the Krasnoyarsk branch of SGC will continue to work on the involvement of ash and slag waste in the economic turnover, thereby reducing their accumulation and reducing the load on the environment. Work will continue on the reclamation of ash dump No. 2 at Nazarovskaya GRES. In addition, the company is considering the possibilities and expanding markets sale of dry ash and slag and for the needs of not only the construction industry, but also other industries.

The use of ash and slag waste from thermal power plants in construction

A lot of ash and slag waste is generated in the process of activity of electric power industry enterprises. The annual flow of ash to ash dumps in Primorsky Krai is from 2.5 to 3.0 million tons per year, Khabarovsk - up to 1.0 million tons (Fig. 1). Only within the city of Khabarovsk, more than 16 million tons of ash are stored in ash dumps.

Ash and slag waste (ASW) can be used in the production of various concretes, mortars, ceramics, thermal and waterproofing materials, road construction, where they can be used instead of sand and cement.
Dry fly ash from electrostatic precipitators of CHPP-3 finds greater application. But the use of such wastes for economic purposes is still limited, including due to their toxicity. They accumulate a significant amount of dangerous elements.
Dumps constantly generate dust, mobile forms of elements are actively washed out by precipitation, polluting the air, water and soil.
The use of such waste is one of the most actual problems. This is possible by removing or extracting harmful and valuable components from the ash and using the remaining mass of ash in the construction industry and the production of fertilizers.

Brief description of ash and slag waste

At the surveyed thermal power plants, coal is burned at a temperature of 1100-1600o C.
During the combustion of the organic part of coals, volatile compounds are formed in the form of smoke and steam, and the non-combustible mineral part of the fuel is released in the form of solid focal residues, forming a dusty mass (ash), as well as lumpy slags.
The amount of solid residues for hard and brown coal ranges from 15 to 40%.

Coal is crushed before burning and, for better combustion, fuel oil is often added in a small amount of 0.1-2%.
During the combustion of crushed fuel, small and light particles of ash are carried away by flue gases, and they are called fly ash. The particle size of fly ash ranges from 3-5 to 100-150 microns. The amount of larger particles usually does not exceed 10-15%.

Fly ash is captured by ash collectors.
At CHPP-1 of Khabarovsk and Birobidzhanskaya CHPP, ash collection is wet on scrubbers with Venturi pipes, at CHPP-3 and CHPP-2 of Vladivostok, dry ash collection is done on electrostatic precipitators.
Heavier ash particles settle on the fireboxes and are fused into lumpy slags, which are aggregated and fused ash particles ranging in size from 0.15 to 30 mm.
Slags are crushed and removed with water. Fly ash and crushed slag are first removed separately, then mixed, forming an ash and slag mixture.

In the composition of the ash and slag mixture, in addition to ash and slag, particles of unburned fuel (underburnt) are constantly present, the amount of which is 10-25%. The amount of fly ash, depending on the type of boilers, type of fuel and the mode of its combustion, can be 70-85% by weight of the mixture, slag 10-20%.
Ash and slag pulp is removed to the ash dump through pipelines.
Ash and slag during hydrotransport and at the ash dump interact with water and carbon dioxide.
They undergo processes similar to diagenesis and lithification. They quickly succumb to weathering and when drained at a wind speed of 3 m / s, they begin to dust.
The color of the ASW is dark gray, layered in the section, due to the alternation of uneven-grained layers, as well as the deposition of a white foam consisting of aluminosilicate hollow microspheres.
Average chemical composition ASW of surveyed CHPPs is shown in Table 1 below.

Table 1. Limits of the average content of the main components of ASW

The content of Ni, Co, V, Cr, Cu, Zn is not more than 0.05% of each element.
Due to their regular spherical shape and low density, microspheres have the properties of an excellent filler in a wide variety of products. Promising directions The industrial use of aluminosilicate microspheres is the production of spheroplastics, road-marking thermoplastics, grouting and drilling slurries, heat-insulating radio-transparent and lightweight building ceramics, heat-insulating unfired materials and heat-resistant concretes.

Abroad, microspheres are widely used in various industries. In our country, the use of hollow microspheres is extremely limited and they, together with the ash, are dumped into ash dumps.
For thermal power plants, microspheres are a "harmful material" that clogs the pipes of circulating water supply. Because of this, it is necessary to completely replace pipes in 3-4 years or carry out complex and expensive work to clean them.

The inert mass of the aluminosilicate composition, which is 60-70% of the mass of ASW, is obtained after the removal (extraction) from the ash of all the above concentrates and useful components and heavy fraction. In composition, it is close to the general composition of ash, but it will contain an order of magnitude less glands, as well as harmful and toxic.
Its composition is mainly aluminosilicate. Unlike ash, it will have a finer uniform granulometric composition due to grinding when extracting the heavy fraction.
For environmental and physical and chemical properties can be widely used in the production of building materials, construction and as a fertilizer - a substitute for lime flour (ameliorant).

The coals burned at the thermal power plant, being natural sorbents, contain impurities of many valuable elements (Table 2), including rare earths and precious metals. When burned, their content in the ash increases by 5-6 times and may be of industrial interest.
The heavy fraction recovered by gravity using advanced concentration plants contains heavy metals, including precious metals. By fine-tuning, precious metals are extracted from the heavy fraction and, as they accumulate, other valuable components (Cu, rare, etc.).
The output of gold from individual studied ash dumps is 200-600 mg per ton of ASW.
Gold is thin, non-recoverable by conventional methods. Know-how technology is used to extract it.

Many people are involved in the disposal of ASW. More than 300 technologies for their processing and use are known, but they are mostly devoted to the use of ash in construction and the production of building materials, without affecting the extraction from them as toxic and harmful components as well as useful and valuable.

We have developed and tested in laboratory and semi-industrial conditions a basic scheme for the processing of ASW and their complete utilization.
When processing 100 thousand tons of ASW, you can get:
- secondary coal - 10-12 thousand tons;
- iron ore concentrate - 1.5-2 thousand tons;
- gold - 20-60 kg;
- building material (inert mass) - 60-80 thousand tons.

In Vladivostok and Novosibirsk, ASW processing technologies similar in type have been developed, possible costs have been calculated, and the necessary equipment has been provided.
Extraction of useful components and complete utilization of ash and slag waste through the use of their useful properties and the production of building materials will free up space and reduce the negative impact on the environment. Profit is desirable, but not the decisive factor.
The costs of processing technogenic raw materials with the production of products and simultaneous neutralization of waste may be higher than the cost of products, but the loss in this case should not exceed the costs of reducing the negative impact of waste on the environment. And for energy enterprises, the utilization of ash and slag waste is a reduction in technological costs for the main production.

Literature

1. Bakulin Yu.I., Cherepanov A.A. Gold and platinum in ash and slag waste from the CHPP of Khabarovsk // Ores and Metals, 2002, No. 3, pp. 60-67.
2. Borisenko L.F., Delitsyn L.M., Vlasov A.S. Prospects for the use of ash from coal-fired thermal power plants./JSC "Geoinformmark", M.: 2001, 68p.
3. Kizilshtein L.Ya., Dubov I.V., Spitsgauz A.P., Parada S.G. Components of ashes and slags from thermal power plants. Moscow: Energoatomizdat, 1995, 176 p.
4. Components of ashes and slags from thermal power plants. Moscow: Energoatomizdat, 1995, 249 p.
5. Composition and properties of ash and slag from thermal power plants. Reference manual, ed. Melentyeva V.A., L.: Energoatomizdat, 1985, 185 p.
6. Tselykovsky Yu.K. Some problems of using ash and slag waste from thermal power plants in Russia. Power engineer. 1998, No. 7, pp. 29-34.
7. Tselykovsky Yu.K. Experience in the industrial use of ash and slag waste from thermal power plants // New in the Russian energy sector. Energoizdat, 2000, No. 2, pp. 22-31.
8. Valuable and toxic elements in commercial coals of Russia: Handbook. M.: Ne-dra, 1996, 238 p.
9. Cherepanov A.A. Ash and slag materials// The main problems of studying and extracting mineral raw materials of the Far Eastern economic region. The mineral resource complex of the FER at the turn of the century. Section 2.4.5. Khabarovsk: Publishing House of DVIM-Sa, 1999, pp. 128-120.
10. Cherepanov A.A. Noble metals in ash and slag waste from Far Eastern thermal power plants // Pacific Geology, 2008. V. 27, No. 2, pp. 16-28.

V.V. Salomatov, Doctor of Technical Sciences Institute of Thermal Physics SB RAS, Novosibirsk

Ash and slag waste from thermal power plants on Kuznetsk coal and ways of their large-scale utilization

Processing scale solid waste coal-fired thermal power plants are extremely low today, which causes accumulation huge quantities ash and slag in ash dumps requiring significant areas to be withdrawn from circulation.

Meanwhile, Kuznetsk coal ash and slag contains valuable components such as Al, Fe, rare metals, which are raw materials for other industries. However, with traditional methods of burning these coals, it is not possible to use ash and slag on a large scale, since due to the formation of mullite, they have a high abrasiveness and are chemically inert to many reagents. Attempts to use ash and slag of such a mineralogical composition in the production of building materials lead to intensive wear technological equipment and decrease in productivity due to the slowdown of physical and chemical processes of interaction of ash components with reagents.

It is possible to avoid mullitation of Kuznetsk coal ash by changing the temperature conditions of their combustion. Thus, the use of a fluidized bed for burning coal at 800–900 °C makes it possible to obtain less abrasive ash, and its main mineralogical phases will be metakaolinite, ?Al2O3; quartz, glass phase.

Utilization of ash and slag wastes from CHP plants at low-temperature combustion of CHP

The amount of ash and slag waste from the most typical thermal power plant with an electric power of 1295/1540 MW and a thermal power of 3500 Gcal/h is about 1.6...1.7 million tons per year.

The chemical composition of Kuznetsk coal ash:

SiO2 = 59%; Al2O3 = 22%; Fe2O3 = 8%; CaO = 2.5%; MgO = 0.8%; K2O = 1.4%; Na2O = 1.0%; TiO2 = 0.8%; CaSO4 = 3.5%; C = 1.0%.

The use of Kuznetsk coal ash is most effective in the production of aluminum sulfate and alumina using the technologies of the Kazakh Polytechnic Institute. Based on the material composition of the KU ash and its quantity, the recycling scheme is shown in Figure 1.

In Russia, only 6 special types of alumina are produced, while only in Germany there are about 80. Their range of applications is very wide - from the defense industry to the production of catalysts for the chemical, tire, light and other industries. The needs for alumina in our country are not covered by our own resources, as a result of which part of the bauxite (raw material for the production of alumina) is imported from Jamaica, Guinea, Yugoslavia, Hungary and other countries.

The use of Kuznetsk coal ash will make it possible to somewhat rectify the situation with a deficiency of aluminum sulfate, which is a means for treating waste and drinking water, as well as those used in large quantities in the pulp and paper, woodworking, light, chemical and other sectors of industry. The deficit of aluminum sulfate only in the region of Western Siberia is 77...78 thousand tons.

In addition, the dispersed composition of alumina obtained after sulfuric acid processing makes it possible to obtain different kinds special alumina, the need for which will be satisfied to a certain extent by their production in the amount of 240 thousand tons.

Wastes from the production of aluminum sulfate and alumina are a raw material for the production of water glass, white cement, binders for backfilling mined-out mining areas, container and window glass.

The need for these materials is increasing, and the demand for them now significantly exceeds their production volumes. Approximate technical and economic indicators of these industries are presented in Table 1.

Table 1. Main technical and economic indicators for the processing of ash from Kuznetsk coals

Name
productions 		Power,
thousand tons 		Price
USD/t 		Self,
USD/t 		Cap.
attachments,
mln. 		Ek
Effect,
mln. 		Term
pay off
years
Specialty production
alumina		 240 33 16 20 4 5
Sulphate production
aluminum		 50 12 7 1 0,25 4
Production
ferroalloys		 100 27 16 5 1 5
Production of liquid
glass		 500 11 8 6 2 3
white production
cement		 1000 5 4 3 0.65 4,6
Binder production
materials		 600 3 2 3 0,6 5
Glass production 300 18 15 5 1 5
TOTAL 42 9 4,7

In addition, it is expedient to produce rare and dispersed metals from the ash of the KU, primarily gallium, germanium, vanadium and scandium.

Due to the fact that the CHPP, according to the conditions of its schedule, operates with a variable load throughout the year, the ash output is uneven. Ash processing plants should work rhythmically. Storage of dry ash presents certain difficulties. In this regard, it is proposed winter time send part of the ash for granulation using pelletizers manufactured by Uralmash. After pelletizing and drying, the granules are fired in the boiler furnace, and then they are sent by pneumatic transport for temporary storage in a dry warehouse. Ash pellets can later be used as a raw material base for the construction industry or used in road construction.

Storage of pellets in an open dry warehouse does not require special protective measures and does not create a dusting hazard. The capacity of such an ash dump is about 350...450 thousand tons, the area is about 300?300 m2. Therefore, it may be located in close proximity to the CHP site.

Ash and slag waste obtained after combustion of CFB in boiler units with a circulating fluidized bed (CFB), which Russia does not yet produce, will have the best utilization rates. CFB boilers provide not only a sharp decline emissions of nitrogen oxides and sulfur, but also produce ash and slag waste, which can be successfully used in industry to produce alumina and building materials. This makes it possible to reduce the cost of the power plant due to a sharp reduction in the areas required for ash storage, reduce pollution environment. Dust reduction at CHPPs with CFB boilers occurs, firstly, due to a decrease in the area of ​​the ash dump, and secondly, due to the fact that the ash obtained by burning Kuznetsk coal in the CFB contains gypsum and has astringent properties. With some wetting of such ash, it will harden, which will eliminate dusting even if the ash dump dries up.

As the ash is transported to industrial enterprises pneumatic transport, water consumption is also slightly reduced. In addition, there is no wastewater from the ash dump, which at CHPPs with traditional pulverized coal boilers contains salts of heavy metals and other harmful substances.

Production of aluminum sulfate and alumina

The technology for producing aluminum sulfate and alumina based on low-temperature combustion ash is shown in Figure 2.

The optimal conditions for the implementation of this technology are as follows:

  • coal burning ( temperature regime 800…900 °C);
  • grinding (grinding fineness - 0.4 mm (at least 90%);
  • sulfuric acid opening (temperature 95 ... 105 ° C, duration 1.5 ... 2 hours, sulfuric acid concentration 16 ... 20%);
  • separation of liquid and solid phases (filter fabric article L-136, rarefaction 400…450 mm Hg, suction filter 0.37…0.42 m3/m2?h);
  • two-stage sludge washing;
  • hydrolytic decomposition (temperature 230 °C, time 2 hours);
  • thermal decomposition (temperature 760…800 °C).

The resulting production aluminum sulfate (50 thousand tons per year) after granulation and packaging in plastic bags is sent to consumers. The performed feasibility study shows the feasibility of aluminum sulfate production based on low-temperature combustion ash.

Ash-derived aluminum sulfate is a good coagulant for industrial wastewater treatment.

Sishtof after sulfuric acid treatment due to the low content of iron oxides (less than 0.5 ... 0.7%) is a substitute for sand in the production of white cement, and the presence of 4 ... 6% gypsum in it will intensify the processes of cement production themselves.

Production of ferroalloys and building materials

The production of ferroalloys based on the mineral part of coals has been thoroughly developed. Testing of industrial technologies for the production of ferrosilicoaluminum and ferrosilicon from ash and slag waste, similar in composition to Kuznetsk coal ash and its magnetic component, which can be isolated by magnetic separation methods, was carried out. The obtained alloys were tested on an industrial scale at the metallurgical plants of the country for steel deoxidation and gave positive results.

Obtaining building materials based on sishtof does not require changes in the existing technologies of these industries. Sishtof is used as a raw material and replaces quartz and other silicon-containing products used in the production of building materials. In addition, silicon oxide, the content of which in sistof is 75–85%, is presented mainly in the form of amorphous silica with high chemical activity, which makes it possible to predict an improvement in the performance and quality of cement and binders. Minimal amount ferruginous and other coloring compounds in sistof makes it possible to obtain white cement on its basis, the need for which is very high.

Technologies for producing cement, binders, and liquid glass have also been developed in industry.

Conclusion

Ash and slag wastes obtained by burning Kuznetsk coal in power steam generators using the circulating fluidized bed technology, which is new for Russia, are in demand for large-scale disposal. It is economically efficient to produce very scarce ferroalloys, aluminum sulfate, special types of alumina, liquid glass, white cement, and binders using technologies already mastered in the industry.

Bibliography Salomatov V.V. Environmental technologies based on thermal and nuclear power plants: monograph / V.V. Salomatov. - Novosibirsk: publishing house of NSTU, - 2006. - 853 p.

74rif.ru/zolo-kuznezk.html, energyland.info/117948

One of the main reasons for this is the heterogeneity and instability of the composition of the produced ash, which does not provide a reliable beneficial effect when it is disposed of in the construction industry - the main potential consumer. The processing of gigantic volumes of ash produced around metropolitan areas with the help of well-known equipment - classifiers and mills, given the low consumer cost and the strong discrepancy in terms of production and consumption, is guaranteed to be unprofitable production.

Ash is a scarce commodity

Incomplete consumption of the produced ash only causes problems for power engineers, since in this case it is necessary to maintain two ash removal systems. Ash removal and the maintenance of dumps used to be about 30% of the cost of energy and heat of CHP. However, if we take into account the market value of the lost land near megacities, the decrease in the cost of land and real estate at a considerable distance from stations and ash dumps, direct damage to human health and nature, in particular, dust pollution of the air basin and soluble salts and alkali of reservoirs and groundwater, then this share is realistic. should be significantly higher.

Fly ash in developed countries is the same commodity, and scarce, as heat and electricity. High-quality fly ash, which meets the standards and is suitable for use in concrete as an additive that binds excess lime and reduces water demand, costs, for example, in the USA on a par with Portland cement ~60$/t.

The idea of ​​exporting recycled coal ash to the US might make sense. Low-quality fly ash, such as from low-temperature "environmentally friendly" fluidized-bed boilers that burn low-quality coal with a high sulfur content (Zeranj station in Warsaw), is offered at a negative cost of the order of -5 $ / t, but on the condition that the consumer takes all of her. The situation is similar in Australia. Thus, the processing of ash can only be profitable if, thanks to technology, a number of better products will appear that will find consumers in full or almost full volume in a limited area near the place of production. With the standard use of fly ash as an additive in concrete or building ceramics, the problem cannot be solved in principle due to the limited capacity of the local market. In addition, the addition of ashes of an unstable composition to concrete is possible without loss of quality only in a very limited amount, which makes this whole undertaking meaningless.

Processing prospects

From a chemical point of view, not using fly ash is absurd. It is possible to distinguish at least 3 types of promising for the processing of evils:
1) high-calcium ash from the combustion of brown coal (BUZ), for example, from the Kansk-Achinsk coal basin, with a high content of calcium oxide and sulfate, i.e., similar in composition to Portland cement and with a high chemical potential - stored energy;
2) acid ash from the combustion of coal (HCC), consisting mainly of glass, including microspheres;
3) ash with a high content of rare earth elements.

It should be noted that in nature there are no two identical coals, therefore there are no identical evils. We should always talk about the local fly ash processing technology in a particular region, since the main consumers should be located near the ash source. Any most remarkable technology will take place only if the local market is able to “swallow” all or almost all of the mass of processed ash.

For complex processing fly ash, it is proposed to use the capabilities of a new class of technology - the so-called electro-mass classifiers (EMC). This technique is based on the recently discovered new phenomenon - education in rotating turbulent gas flows of dense charged aerosols (gas-dust plasma) and their separation in internal electric fields.

The phenomenon of tribocharging of particles during friction or impacts has been known to mankind since time immemorial, but until now science cannot even predict the sign of the charge.

Benefits of EMC

Despite the extreme complexity of the phenomenon, the EMC technique is outwardly very simple and has advantages in all respects relative to conventional air separators or jet mills, disintegrators.

One of the main advantages is complete environmental friendliness, since the processes are carried out in a closed volume, i.e. EMC does not need any additional devices such as compressors or dust collection systems - cyclones or filters, even when working with nanopowders. A fine fraction of an aerosol charged with one sign is removed from the aerosol by the Coulomb force through the center, against the action of the Stokes viscosity force and the centrifugal force. The particles are discharged on the walls in the capture chamber or through charged ions in the atmosphere, and the charge is returned to the aerosol generation chamber.

Thus, in the EMC technique, the process of separating powders into an unlimited number of fractions with a charge cycle is carried out. When separating heterogeneous systems, including ash, it is possible to separate not only by particle size, but also by other physical characteristics.

Another important advantage of EMC is the ability to simultaneously implement several different operations in one pass (for example, separation with mechanical activation or grinding), both in continuous and discrete versions. Huge masses of ash with a high content of fine particles cannot be separated using known technology, since it is inefficient dust collection of precisely fine particles that have the highest value and at the same time pose the greatest danger to people and the environment.

The separation of the fine fraction from the fly ash on the EMC makes it possible to effectively continuously separate the coarse fraction according to other parameters, for example, particle size, magnetic susceptibility, density, particle shape, electrical properties. The performance range of the EMC technique has no analogues: from a portion of 1 gram to 10 tons / hour in continuous mode with a rotor diameter of not more than 1.5 m. The dispersion range of the separated materials is also wide: from hundreds of microns to ~ 0.03 microns - far exceeds all famous species technique, approaching wet separation using centrifuges.

Ash processing technologies

The capabilities of EMC allow implementing a flexible "smart technology" for ash processing with a focus on the market potential of its individual components. Detailed study a number of fly ash, including CHPP-3 and CHPP-5 of Novosibirsk, made it possible to develop optimal schemes for their processing, as well as to propose technologies for the production of building materials with the utilization of the bulk of products from ash.

BUZ, obtained in particular at CHPP-3, consists mainly of glass spherical particles with a variation in the content of calcium and iron. These particles have astringent properties and, when reacting with water, are slower than Portland cement, but form a cement stone. However, along with them there are particles of unburned coal in the form of coke, the content of which can reach up to 7%, grains of calcium oxide CaO (5-30%) and calcium sulfate CaSO4 (5-15%), covered with glass, inactive minerals - quartz and magnetite. Coke has a uniquely negative effect on the strength of the stone, similar to macropores.

But the most negative role is played by CaO grains, especially large ones. These grains react with water with a significant increase in volume and noticeably slower than the bulk of the ash, including due to glass encapsulation.

The action of large CaO particles can be compared to a time bomb. The strength of ash-based stone is usually low and averages about 10 MPa (100 kg/cm2), but due to the unstable composition, it varies from 0 to 30 MPa. Consumer value is determined lower bound, i.e., equal to zero. For the selection of ash of a suitable composition, an express analysis is required, which requires an expensive spectrometer. The selection for disposal of only part of the ash is not of any interest.

The mechanical treatment of ash at the EMC in the mode of mechanical activation of the particle surface with the simultaneous separation of approximately 50% of the fine fraction less than 60 μm solves the above problems.

The optimal shelf life of the activated fine ash fraction with an additional increase in stone strength by ~5 MPa is 1 5 days, after which the cracks close with a decrease in activity below the initial one.

This feature of the ash binder requires the processing of ash mainly by the consumers themselves. The strength of the stone under optimal activation and storage conditions no longer drops below 10 MPa, and with small additions of cement of the order of 10%, and calcium chloride CaCl2 of approximately 1%, (the so-called winter additive that activates the reaction with small grains of sand), the ash binder becomes a full-fledged, but cheap material for the preparation of non-shrinking low-grade concrete M100-M300.

The brand of concrete is determined by its strength after 28 days of exposure, but concrete with an ash binder gains strength further, increasing it by 2-3 times (in ordinary concrete - only by 30%). The coarse fraction can be easily recycled: separation by particle size or on a triboelectric separator gives a coarse fraction of coke, which can be returned to the boiler, a fraction of spherical magnetite particles is separated on a magnetic separator, which can be used, for example, as a special pigment. The residue after mixing with water for 1-2 weeks is a plaster or mortar.

Ash Bion

The figure shows the strength of the stone at different ratios of cement and ash binder. Three areas can be distinguished: low-grade concrete based on ash binder with small additions of cement, ordinary concrete with small additions of 10-20% ash binder, and concrete of maximum strength with the addition of ash binder 25-50%. If ash binder is used as an additive, then the entire market in the metropolis will be able to consume only a small part of the ash produced.

The production of concrete with a large addition of ash binder up to 50%, despite the attractiveness, is a high-risk area. This is due to the fact that the proportion of calcium sulfate CaSO4 in the ash varies within 5, and its high content can lead to the formation of ettringite when reacting with the aluminous component of cement with a large increase in volume already after the formation of a strong stone. In this regard, the formation of ettringite is called the plague for concrete.

It is relatively easier to find a use for low-grade concrete. In this case, the maximum volume of ash binder, for example, from CHPP-3 ash, will be 60 thousand tons per year, from which 200 thousand cubic meters can be prepared. m of concrete. It will be enough to build 3,000 low-rise individual houses or to cover 200 km of local roads with a width of 8 m. Ash can be stored in dry conditions for an arbitrarily long time, so the mismatch in terms of production and consumption will not affect the quality of ash processing at the construction site.

The processing of acid HSCs, which are mainly glass spherical particles, including hollow microspheres, and unburned coal residues in the form of coke up to 5%, is also easily implemented using the EMC technique. Microspheres, which make up about 5% of ash, have many special applications, up to medicine.

The main consumers of KUZ, in addition to concrete producers, are brick factories. Unfortunately, clays in Russia tend to be lean and ash additions are not necessary. The potential capacity of the regional market for HPU products is still several times lower than the volume of ash produced. Export option to the developed countries ash products must be calculated.

In the UK, low-quality waste is laid in the foundations of roads. Up to 10-20% of the produced HPU can be utilized usefully as a flocculant in the production of soil blocks during organized construction in semi-autonomous eco-villages of individual low-rise housing. The holistic concept of building affordable comfortable housing based on local resources and waste is set out in the New Low-rise Russia project and is available on the Internet. In general, for HPUs, the market needs to be formed within a few years if there is investment.

Why is recycling needed?

Unfortunately, both road construction and individual construction through land relations is completely dependent on officials. These areas are traditionally the least transparent, allowing corruption to flourish. Innovation in these areas is really impossible without the political will of the authorities.

Waste-free use of fossil coals is especially beneficial for the state from a strategic point of view, since the volume of production of binders will double without additional costs, and in addition, due to coal, gas consumption within the country will significantly decrease, which will increase its sales abroad. The production of an alternative binder based on ash will provide competition in the sector of low-grade concrete to regional cement monopolists.

Zyryanov Vladimir Vasilievich,

Energy and industry of Russia

As it often happens, it was not we who came up with the idea of ​​using ash to produce building materials, but the practical West - ash and slag materials have long been widely used there in construction and housing and communal services. Main value new method of manufacturing building materials from ash - nature conservation.

Rejoice, environmentalists and Greenpeace: the danger of environmental disasters associated with the danger of erosion of ash dumps and pollution of the environment by ash is reduced to a minimum. There is a huge cost savings - after all, a lot of money is spent on the maintenance of ash storage facilities. Other benefits of ash recycling are economic benefit use of this resource.

A brick created from ash is suitable for building a residential building, a production facility, and a fence. It can even be used as a facing. The recipe for making such a brick is extremely simple: 5% water, 10% lime, the rest is ash (salt and pepper to taste).

The modern price of such a brick, produced, for example, at the Omsk plant (SibEK LLC - Siberian efficient brick) is 5–6 rubles, which makes this “product” very competitive.

Brick tests prove it high quality and wide application possibilities. Strength, water absorption, frost resistance are not inferior to silicate brick. The thermal conductivity index is close to that of wood. Yes, and the appearance pleases with its almost perfect shape - the dimensional tolerances of such a brick are not more than 0.5 millimeters, and this, if you think about it, is again savings - this time on the amount of setting solution. In addition, ash brick is lighter, more convenient in masonry, and allows you to make it flawlessly even. For improvement appearance bricks, dyes can be added to its composition.

Life pushes to search for new ideas and solutions. The use of ash as a raw material for bricks and other building materials is a truly successful and very timely discovery. The number of “killed hares” in this case is much more than the notorious two. And once again the proverb is confirmed that everything of value is under our feet.

Everyone knows that one of the most versatile and ancient fertilizers is wood ash. It not only fertilizes and alkalizes the soil, but creates favorable conditions for the vital activity of soil microorganisms, especially nitrogen-fixing bacteria. It also increases the vitality of plants. It has the most favorable effect on the crop and its quality than industrial potash fertilizers, since it contains almost no chlorine.

The Technoservice company was able to organize the production of deep utilization of bark and wood waste, and, as a result, received an environmentally friendly complex fertilizer of prolonged action - granulated wood ash (DZG).

The main advantages of DZG:

  • An attractive feature of this product is its new granular format. The size of the granules is from 2 to 4 mm, it is convenient for packaging and transportation, it is easy to transport it by any means of transport in containers or bags, it is convenient to apply it to the soil by any type of equipment. The granular format contributes to more favorable working conditions for the staff.
  • Processing and application of dusty ash is a very complex process. To reduce the level of dusting when applying agricultural fertilizers, it is more efficient to use granular ash. Granulation facilitates the process of applying ash, and also slows down the process of ash dissolution in the soil. Slow solubility is an advantage, as agricultural land is not subjected to shocks associated with changes in acidity and nutrient medium.
  • The introduction of granulated wood ash is the most effective way to combat the process of soil acidification. In addition, the soil structure is restored - it becomes loose.
  • Wood ash granulated contains everything, with the exception of nitrogen, the nutrients necessary for plants. DZG practically does not contain chlorine, so it is good to use it for plants that react negatively to this chemical element.
  • Wood ash granulated is stored and indefinitely stored in standard dry warehouses for storage of mineral fertilizers at natural humidity and air ventilation.

Land investment

Ash fertilizers from Technoservice are the best investment in your land. Wood ash granulated is an efficient, environmentally friendly and income-generating element of a responsible farmer.

By introducing DZG, you guarantee an increase in the value of your lands and their safety for future generations. Thus, you can profitably use your soil as an object of long-term investment. Thanks to a good choice of object, even non-profitable land will turn into a fully cropped part of the farm property. natural proportions nutrients, long duration of exposure, slow solubility and uniform distribution make DZG Technoservice LLC an excellent solution for both Agriculture as well as from an environmental point of view!

DZG - to increase productivity!

During field research, in accordance with the Leningrad region program conducted in 2008-2011. on acid soddy-podzolic soil, withdrawn from agricultural use about 5 years earlier, it was possible to draw the following conclusions:

  • Wood ash from boiler houses is suitable for increasing fertility and eliminating hyperacidity soddy-podzolic soils.
  • A total increase in crop yields of 25-64% over 3 years of crop rotation was obtained due to only one measure: liming of slightly acidic soddy-podzolic soil with wood ash from boiler houses.
  • During complex tillage together with mineral and organic fertilizers significantly higher yields can be achieved.
  • It is recommended to use wood ash from boiler houses as a chemical ameliorant during periodic and maintenance liming of acidic soddy-podzolic soils.

According to the All-Russian Research Institute of Agrochemistry D.N. Pryanishnikov DZG can be used as mineral fertilizer with the properties of an ameliorant for the main application for agricultural crops and ornamental plantings on acidic and slightly acidic soils in open and protected ground.

Approximate norms and terms of application in agricultural production:

  • all crops - the main or pre-sowing application at the rate of 1.0-2.0 t/ha;
  • all crops - the main application (as an ameliorant to reduce soil acidity) at the rate of 7.0-15.0 t/ha with a frequency of 1 time in 5 years.

Approximate doses, terms and methods of applying an agrochemical in personal subsidiary plots:

  • vegetable, flower-decorative, fruit and berry crops - application during tillage in autumn or spring or during sowing (planting) at the rate of 100-200 g/m2;
  • vegetable, flower-decorative, fruit and berry crops - application during tillage in autumn or spring (as an ameliorant to reduce soil acidity) at the rate of 0.7-1.5 kg/m2 with a frequency of 1 time in 5 years.