Applications of ash аnd slag waste in agriculture

Environmental pollution creates problems for health of people living in residential areas near pollution sources. Studies aimed at developing methods for investigating the impact of industrial facilities on the air is of interest. The purpose of this work is to analyze the methodology for assessing the risk of exposure of a technosphere object to the atmosphere. It was assumed that the enterprise in emergency mode emits pollutants through the source of emissions at the maximum single concentration of the substance exceeding the maximum permissible concentration. To calculate the impact on a human, various scenarios of an emergency situation are taken into account. These are constructing failure trees and using well-known health risk assessment techniques. The calculation took into account the wind rose for a specific enterprise location and wind speed projections obeying the normal distribution law. These assumptions allowed us to develop a method for calculating the risk of exceeding the concentration of a pollutant at a given point (x, y) during the year. Isolines of surface concentrations were built. Three toxic substances were taken for analysis. The method for calculating the dispersion of emissions of harmful (polluting) substances in the atmospheric airwas used; maps of the dispersion of isolines of pollutants in residential areas were constructed. When solving the inverse problem, emergency emission intensities at which excess of permissible concentrations occurred were determined. In the range of multiplicities exceeding the maximum single maximum permissible concentration from 1 to 5, the dependence was well approximated by a straight line. This technique can be used to determine the risk of diseases caused by carcinogenic and noncarcinogenic substances and minimize the risk of exposure to harmful substances. Ash and slag wastes are the source of negative impact on the environment. This area is studied by a number of researchers. The article aims to systematize the data on possible applications, accumulated practical experience of using ash and slag waste in agriculture both in Russia and abroad. The analysis showed that waste from the fuel and energy industry can be widely used in various areas of agriculture. It can be used as ameliorants, zeolite-based mineral fertilizers, pesticides and insecticides for treating horticultural crops, microfertilizers, as well as for soil remediation and land reclamation. The use of ash and slag waste in agriculture and other sectors of the national economy can reduce the ecological load on the environment. The number of overfilled ash dumps can be reduced, and there will be no need to build new ones.

Analysis of the chemical composition and technological process of processing ash and slag waste from chpp

This article studies sorption method of extraction of rare earth elements (REEs) from ash and slag waste of Novo- Angren TPP. In this regard, the possibility of extracting REE from acidic solutions on the Purolite C100-H cation exchanger was investigated in the example of one of the REEs, lanthanum. Furthermore, dependence of the sorption of lanthanum on Purolite C-100N cation exchanger on pH of solution and dependence of the sorption of lanthanum on the Purolite C-100H cation exchanger on the concentration of the equilibrium solution were studied. In addition, lanthanum sorption was calculated from the difference in concentrations in the initial and equilibrium solutions.

INFORMATION CONTENT OF MODELS FOR DETERMINING THE ENVIRONMENTAL CHARACTERISTICS OF THE ENERGY FACILITIES FUNCTIONING

В статье сформирована последовательность выполнения действий по определению экологических характеристик функционирования объектов энергетики. Приведены показатели энергообъектов и справочные данные, необходимые для получения промежуточных показателей этапов исследований. Дано описание расчетных моделей определения массы выбросов в атмосферу загрязняющих веществ и парниковых газов и массы образующихся золошлаковых отходов. Модели разработаны на основе утвержденных методик для тепловых электростанций, котельных и дизельных электростанций. Показано, что технологии расчетов экологических характеристик для каждой категории энергообъектов зависят от вида сжигаемого топлива и типа используемого оборудования. Выполнена систематизация информации для моделей определения экологических характеристик функционирования энергетических объектов. Вся необходимая информация представлена в виде трех крупных блоков: характеристика населенных пунктов; показатели энергообъектов; справочные данные по видам топлива, энергетическому и улавливающему оборудованию. Приведено подробное описание показателей каждого блока информации. Показана зависимость перечня определяемых экологических характеристик энергообъектов от вида сжигаемого топлива. Обозначены источники информации и доступность получения показателей каждого блока. The article forms a sequence of actions to determine the environmental characteristics of the functioning of energy facilities. The indicators of energy facilities and reference data required to obtain intermediate indicators of research stages are presented. A description of the models for determining the mass of emissions of pollutants and greenhouse gases into the atmosphere and the mass of ash and slag waste are described. The models are developed on the basis of approved methodologies for thermal power plants, boiler houses and diesel power plants. It is shown that technologies for calculating environmental characteristics for each category of energy facilities depend on the type of fuel burned and the type of equipment used. The systematization of information for models to determining the environmental characteristics of the functioning of energy facilities has been carried out. All the necessary information is presented in the form of three large blocks: characteristics of settlements; indicators of energy facilities; reference data on types of fuel, energy and capture equipment. A detailed description of the indicators of each block of information is given. The dependence of the list of determined environmental characteristics of energy facilities on the type of burned fuel is shown. The sources of information and the availability of obtaining indicators for each block are indicated.

Modern trends in the development of the construction industry in the production of building materials

The paper describes the technology of manufacturing a construction product by vibrocompression using ash and slag waste from thermal power plants in the Pavlodar region. The task of the experimental research was to obtain a hollow wall stone based on ash and slag waste with a strength grade that is not inferior to products made according to the traditional recipe. The obtained samples with different ratios of components in the mixture were investigated for compressive strength, moisture absorption, frost resistance. It has been established that when ash and slag waste are added to the composition of the concrete mixture in an amount of up to 35 % of the mass of dry components, the strength characteristics of the hollow wall stone correspond to the selected brand

A Promising Method of Utilization of Ash and Slag Waste of Variable Composition at Coal-fired Power Plants

A comparative analysis of ash and slag waste (ASW) of six deposits, differing in quantitative chemical and phase composition, granulometry, melting temperature and other properties, is presented, and the production of a material promising for the construction industry is proposed – aggloporite, the production technology of which practically does not depend on the composition and properties of TPP ash. Aggloporite can also be used in road construction to form side slopes. The proposed method of recovery of large volumes of ash and slag waste accumulated at a number of power plants opens up opportunities to improve the environmental situation in the areas located in the vicinity of coal power plants, free up significant land areas occupied by ash and slag waste storage facilities, and reduce the harmful effect of waste on soil, water and air.

Composite Сarbonaceous Сoal-Water Suspensions

In Ukraine, up to 75% of all electricity is supplied by thermal power plants, the main type of fuel for which is coal, which leads to the release of ash and slag waste at power plants in huge quantities. Every 10 years (according to statistical data) the amount of ash and slag produced at thermal power plants doubles. The use and creation of new modified consumers of coal-water fuel (CWF) and coal-water suspensions (CWS) occurs periodically. The ease of handling suspensions is captivating: in the energy sector, they can serve as the basis for the effective disposal of numerous accumulated wastes from coal preparation and oil refining, a significant reduction in the consumption of minerals for generating heat and electric energy, and minimizing the effect of heat power engineering on public health and the state of nature.

Innovational Construction Materials of LLP “EcostroyNII-PV” Production

The article discusses the experience of recycling industrial waste from the electric power industry and metallurgy. Based on the experience of Ecostroy NII-PV LLP. The proposed technology for manufacturing building products from ash and slag waste provides innovative compositions of raw mixtures. What provides an increase in operational characteristics and labor productivity in construction. The applied technology, in comparison with the existing analogues, provides for the use of local waste (ash and slag waste from the combustion of Ekibastuz coal, bauxite sludge from the Pavlodar aluminum plant, steel-making slags), differing in chemical and granulometric composition. as well as binding properties from other analogs and prototypes. In the manufacture of building products introduced mixture, including, wt %: slag Portland cement - 14.32-17.00; sand - 18.74-25.52, crushed stone - 46.50-49.71, sludge from alumina production obtained during the recycling of bauxite from Kazakhstan - 5-7; self-disintegrating steelmaking slag - 5-7; ash and slag waste from thermal power plants from burning Ekibastuz coals - 5-7. According to the test results, the average tensile strength of building products (paving slabs, curbs, hollow bricks) is 3.2 - 3.8 MPa (strength class V2.5).

Complex Technology of Ash and Slag Waste from Power Plants

The development of a comprehensive technology for the processing of ash waste (ASW), which is based on the extraction of carbon from the CSO by flotation method and iron-containing minerals by means of magnetic separation, is presented. The proposed approach is based on the extraction of carbon from ash and slag by flotation and iron-containing minerals by magnetic separation. In this work, the optimal size of the ash fraction supplied for flotation was established. It is shown that when the technological process is carried out according to the stadium scheme when flotation reagents are fed in fractions, it allows their consumption to be reduced and the recovery of carbon concentrate from underburning to be significantly increased. The developed technology was tested on a pilot plant. High-quality carbon, iron-containing and aluminosilicate products were obtained. Auxiliary enrichment processes such as classification, thickening and filtration were tested.

The geoecological analysis performed for the geochemical composition of ash and slag waste obtained at Zmiiv thermal power plant

The objective of the study was the composition of ash and slag waste from the Zmiiv TPP (thermal power plant) and the peculiarities of migration of heavy metals (HM) from the place of storage of ash and slag waste into the ecosystem. To achieve this goal, the following tasks were solved: chemical analysis of ash and slag waste of the Zmiiv TPP; identification of the probability of HM migration into the soil environment in the places of ash and slag waste storage. Ash and slag of the Zmiiv TPP contain Cu, Cr, As, Cd, Ni, Pb in quantities several times higher than the threshold limit value (TLV). For ash and slag wastes, the total pollution rate was Zc = 43, which corresponds to a high level. That is, this artificial horizon is dangerous. HMs migrate to groundwater and soils near the ash stockpiles as a result of infiltration of precipitation waters, leaks from water-bearing communications, water filtration through the base of the ash stockpiles of the Zmiiv TPP. To determine soil contamination near the ash stockpiles, we analyzed soil at the distances of 0, 5, 10, 50 and 100 meters. The contents of the HM decreased further away from the stockpiles. At the distance of up to 100 meters from the dump, there were excesses of the threshold limit values for Ni, Cu, As, Cr in the soil. The concentration factor exceeded one for Cr, As, Cu, Cd, Ni. Only at the distance of 100 meters did the contents of Pb and Zn reached the background values. The calculation of the total rate of soil contamination allowed us to classify these soils as moderately dangerous and acceptable. However, the Zn indicator has several significant disadvantages, particularly it does not take into account the differences in the potential hazards of the elements, as well as, most importantly, the synergistic effects of polymetallic pollution. The coefficient of synergistic effect of heavy metals was 26.64 (in the soil of the ash stockpiles), then decreased, but even at the distance of 100 meters it equaled 11.23, i.e. at the distance of 0... 100 m from the ash stockpiles, the overall actions exceed the norm. The study revealed that Cu, Ni, Zn and Cr had low mobility in the soil near the ash stockpiles and therefore accumulated near the stockpiles, which may be explained by neutral and slightly alkaline soil pH values. The ratio of mineral phases and glass varied, but we should note the predominance of aluminosilicates, calcium silicates and glass in the ash and slag wastes. Heavy metal compounds are confined mainly to amorphized clay aggregates and soot-coal ash formation, to a lesser extent to slag glass and even less to grains of quartz sand. Since ash contains such fractions that can be easily carried by the wind, it should be assumed that ingress of HM into the ecosystem occurs by air, which also contributes to air pollution. The solution to the problem of ash and slag waste disposal can be found in their utilization in the production of construction materials, in road construction, but it is necessary to study the composition of ash and slag and the probability of migration of HM depending on the conditions of use.