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.

On possibility of using silicomanganese slag and ladle electric steelmaking slag in manufacture of welding fluxes

Analysis of the existing trends in development of technologies for production of welding and surfacing fluxes showed that one of the actively developing areas is the production of fluxes using man-made waste (including metallurgical one) as components of the initial charge. This is due to the fact that the slag waste of metallurgical production contains a large amount of manganese and silicon, which in turn are the basis in welding fluxes. Within the framework of this direction development, the article describes principal possibility and efficiency of using materials based on ladle electric steelmaking slag from JSC “EVRAZ United West Siberian Metallurgical Combine” and slag produced by silicomanganese from LLC “West Siberian Electrometallurgical Plant” in the charge for production of fluxes used in the surfacing of rolling rolls. All the laboratory tests were made using the equipment of the scientific and production center “Welding Processes and Technologies”. For surfacing steel samples, the authors used a flux additive obtained by mixing ladle electric steelmaking slag of a fraction less than 0.2 mm with liquid sodium glass in a ratio of 62 and 38 %. The resulting flux additive was mixed with slag from the production of silicomanganese of a fraction of 0.45 - 2.50 mm in various ratios. Studies of the chemical composition (by the spectral method) and metallographic studies of the deposited layer revealed a tendency to an increase in sulfur content and in contamination with non-metallic inclusions in it with an increase in content of the flux additive in the charge of more than 20 %. According to the results of visual quality control of the deposited layer macrostructure, the absence of defects was established with a flux additive content of up to 30 %.

The use of aluminum slag waste in the preparation of roof tiles

Aluminum slag waste generated from the smelting process of bauxite was used to prepare roof tiles samples. Clay was substituted by slag waste in percentages reaching 40% in the basic mix and the plasticity of the obtained mud was determined. This was followed by pressing the mud in steel molds and drying. The effect of waste addition on drying shrinkage was subsequently assessed. Firing of the green bodies was carried out at three temperatures (900, 1000 and 1100oC) and hour soaking at each temperature. Fired roof tile properties improved on increasing the percentage of alumina sludge and firing temperature possibly because of the presence of high amounts of fluxing oxides in aluminum slag. This caused a drop in porosity that increased the mechanical strength of tiles. The results showed that the substitution of clay by 40% waste and firing at 1100oC resulted in products conforming to ASTM C-1167 for clay type roof tiles. Cold water absorption dropped to 12%, below the maximum permissible limit of 15%, the value of Saturation Coefficient was 0.83, below the 0.86 limit and the obtained breaking strength of 3370N significantly exceeded the minimum requirement of 890N.

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.