scholarly journals Fly ash and slag utilization for the Serbian railway substructure

Transport ◽  
2016 ◽  
Vol 33 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Mirjana Vukićević ◽  
Zdenka Popović ◽  
Jovan Despotović ◽  
Luka Lazarević

Approximately 7 million tons of fly ash and slag are produced in thermal power plants in Serbia every year, only 3% of which is used in the cement industry. About 300 million tons of the ash-slag mixture are disposed in landfills, occupying an area of approximately 1600 hectares and generating environmental issues. Fly ash from Serbian power plants has pozzolanic properties and due to low concentration of calcium compounds (less than 10% CaO), they do not have self-cementing properties. According to the ASTM C618-15, this ash is from class F. According to the European Standard EN 197-1:2011, this ash is siliceous (type V) ash. From April 2014 to May 2015, an investigation of engineering properties of fly ash and mixtures of fly ash and slag from landfill (without or with binders of cement/lime) was conducted at the Laboratory of Soil Mechanics at the Faculty of Civil Engineering of the University of Belgrade (Serbia) and at the Institute for Testing of Materials – IMS Institute in Belgrade. The laboratory test results were showed in the study ‘Utilization of fly ash and slag produced in the TPP JP EPS thermal power plants for construction of railways’. Four kinds of waste materials from Serbian power plants were laboratory tested: (a) an ash-slag mixture from landfills at the ‘Nikola Tesla A’ thermal power plant; (b) fly ash from silos in the ‘Nikola Tesla B’ thermal power plant; (c) an ash-slag mixture from landfills at the ‘Kostolac A’ and ‘Kostolac B’ thermal power plants and ‘Srednje kostolačko ostrvo’ landfill; (d) fly ash from the ‘Kostolac’ thermal power plant. The following physical and mechanical properties of ash and mixtures were investigated: grain size distribution, Atterberg limits, specific gravity, moisture-density relationship, shear strength parameters in terms of effective stresses, California Bearing Ratio (CBR), and deformation parameters. The paper presents the results of laboratory tests of the materials with and without binders, and based on the laboratory results and previous research, the paper presents possibilities of using fly ash and slag for the construction of railway substructure in the planned construction and reconstruction of railway network in Serbia. The obtained results indicate that tested fly ash and ash-slag mixture have met the technical requirements and that they have the potential to be used in railway substructure.

Author(s):  
Milica Vlahović ◽  
◽  
Aleksandar Savić ◽  
Sanja Martinović ◽  
Nataša Đorđević ◽  
...  

Electric power in Serbia is predominantly provided by thermal power plants. All of eleven existing thermal power plants in Serbia use coal, mainly lignite in the electricity production process thus generating about 6 million tons of fly ash per year. The estimated amount of fly ash from thermal power plants accumulated in Serbian landfills exceeds 200 million tons. On the other hand, during the last decades, respecting the principles of ecologically sustainable development has been imposed on industries, and one of them is the construction industry. Due to the presence of amorphous SiO2 and Al2O3, fly ash as pozzolanic material is convenient for the production of concrete and mortar. Consequently, multiple positive effects can be expected by the proper consumption of fly ash- reducing landfills and improving concrete properties. The idea of ​​this study is to analyze the possibility of recycling fly ash from a thermal power plant by replacing a part of common mineral filler- limestone in the production of self-compacting concrete (SCC). Properties of conventional SCC with limestone and compositions with different fly ash content were compared. Considering that requirements for SCC should be satisfied and all properties remain or enhance in the case of fly ash addition, this study proved that all designed concretes can be used for structural applications.


Author(s):  
Ye. G. Polenok ◽  
S. A. Mun ◽  
L. A. Gordeeva ◽  
A. A. Glushkov ◽  
M. V. Kostyanko ◽  
...  

Introduction.Coal dust and coal fi ring products contain large amounts of carcinogenic chemicals (specifically benz[a]pyrene) that are different in influence on workers of coal mines and thermal power plants. Specific immune reactions to benz[a]pyrene therefore in these categories of workers can have specific features.Objective.To reveal features of antibodies specifi c to benz[a]pyrene formation in workers of coal mines and thermal power plants.Materials and methods.The study covered A and G class antibodies against benz[a]pyrene (IgA-Bp and IgG-Bp) in serum of 705 males: 213 donors of Kemerovo blood transfusion center (group 1, reference); 293 miners(group 2) and 199 thermal power plant workers (group 3). Benz[a]pyrene conjugate with bovine serum albumin as an adsorbed antigen was subjected to immune-enzyme assay.Results.IgA-Bp levels in the miners (Me = 2.7) did not differ from those in the reference group (Me = 2.9), but in the thermal power plant workers (Me = 3.7) were reliably higher than those in healthy men and in the miners (p<0.0001). Levels of IgG-Bp in the miners (Me = 5.0) appeared to be lower than those in the reference group (Me = 6.4; (p = 0.05). IgG-Bb level in the thermal power plantworkers (Me = 7.4) exceeded the parameters in the healthy donors and the miners (p<0.0001). Non-industrial factors (age and smoking) appeared tohave no influence on specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers.Conclusions.Specific immune reactions against benz[a]pyrene in the miners and the thermal power plant workers are characterized by peculiarities: the miners demonstrate lower levels of class A serum antibodies to benz[a]pyrene; the thermal power plant workers present increased serum levels of class G antibodies to benz[a]pyrene. These peculiarities result from only the occupational features, but do not depend on such factors as age, smoking and length of service at hazardous production. It is expedient to study specific immune reactions to benz[a]pyrene in workers of coal mines and thermal power plants, to evaluate individual oncologic risk and if malignancies occur.


Akustika ◽  
2021 ◽  
pp. 133-137
Author(s):  
Vladimir Tupov ◽  
Vitaliy Skvortsov

The power equipment of thermal power plants is a source of noise to the surrounding area. One of the sources of noise for the surrounding area are gas distribution points (GDP) of thermal power plants (TPP) and district thermal power plants (RTS). Noise from gas distribution points may exceed sanitary standards at the border of the sanitary protection zone. The article shows that the radiated noise from gas distribution points depends on the power of the thermal power plant (natural gas consumption) and the type of valves. Three types of valves used in gas distribution points are considered. Formulas are obtained for calculating the width of the sanitary protection zone for gas distribution points for thermal stations, depending on the consumption of natural gas (electric power of the thermal power plant) and the type of valve. It is shown that, depending on the valve used, the noise level at the border of the sanitary protection zone can either meet sanitary standards or exceed them. This allows at the design stage to select the required type of valve or to determine mitigation measures from hydraulic fracturing.


Author(s):  
Suchismita Satapathy

All companies are dependent on their raw material providers. The same applies in the case of thermal power plants. The major raw material for a thermal power plant is the coal. There are a lot of companies which in turn provide this coal to the thermal power plant. Some of these companies are international; some are local, whereas the others are localized. The thermal power plants look into all the aspects of the coal providing company, before settling down for a deal. Some people are specifically assigned to the task of managing the supply chain. The main motive is to optimize the whole process and achieve higher efficiency. There are a lot of things which a thermal power plant looks into before finalizing a deal, such as the price, quality of goods, etc. Thus, it is very important for the raw material providers to understand each and every aspect of the demands of the thermal power plant. A combination of three methods—Delphi, SWARA, and modified SWARA—has been applied to a list of factors, which has later been ranked according to the weight and other relevant calculations.


2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Jong-Hwan Park ◽  
Se-Wook Hwang ◽  
Su-Lim Lee ◽  
Jae-Hoon Lee ◽  
Dong-Cheol Seo

AbstractThis study evaluated the characteristics and mechanism of phosphate adsorption by fly ash discharged from a biomass thermal power plant (BTP-FA) under various environmental conditions in order to increase the recyclability of BTP-FA. The phosphate adsorption properties of BTP-FA and fly ash derived from coal thermal power plant (CTP-FA) were better matched by those predicted by the Langmuir isothermal model and the pseudo-second-order model, and their maximum adsorption capacities were 62.1 and 4.1 mg/g, respectively. It was found that the adsorption of phosphate by BTP-FA was predominantly influenced by the outer boundary layer rather than the inner diffusion in the pores. The phosphate adsorption process by BTP-FA was greatly influenced by the initial pH and the BTP-FA dose. Therefore, to effectively treat phosphate using BTP-FA, the concentration and flow rate of phosphate in the incoming wastewater must be considered. The concentration of dissolved calcium from BTP-FA decreased sharply during the phosphate adsorption process compared to that in the phosphate-free solution. This was thought to be due to surface adsorption/reaction between calcium and phosphate. The SEM–EDS and FTIR results also supported the surface adsorption/precipitation reaction of Ca-P. Recycling fly ash discharged from biomass power plants as phosphate adsorbents is expected to contribute not only to waste reduction, but also to wastewater purification.


Vestnik MEI ◽  
2021 ◽  
pp. 66-76
Author(s):  
Pavel V. Roslyakov ◽  
◽  
Saina A. Sivtseva ◽  

According to the Russian environmental legislation, all sources of atmospheric pollution at Category I industrial enterprises must necessarily be equipped with automatic systems for monitoring and accounting of marker pollutants emissions. Such industrial facilities include more than 100 thermal power plants. The list of marker pollutants has been established in the relevant industry information and technical reference books on the best available technologies (ITR BAT). The list of marker pollutants monitored at thermal power plants by automatic systems includes nitrogen oxides NOX, sulfur dioxide SO2, carbon monoxide CO, and solid fuel ash. The use of domestically produced measuring equipment for these purposes is set forth as a priority task. However, there is currently no systematic information about gas analysis systems available in the market. The measuring instruments are analyzed, and a database of domestic sampling and non-sampling gas analytical systems is set up, which includes the main methods and means of measuring pollutants emissions, the technical characteristics of which meet the requirements of regulatory documents, and which allows specialists to optimally choose measuring instruments for organizing a continuous emission monitoring system (CEMS) at thermal power plants, taking into account specific conditions and requirements. The Microsoft Access Relational Database Management System (DBMS), which is a flexible database management system, is used to create the database. The developed database of measuring instruments for emission monitoring includes equipment from 33 Russian companies. The DBMS enables the user to organize data in tabular form and produce requests for selecting certain specified parameters. Both basic and additional criteria for selecting measuring instruments can be included in the request form. The developed DBMS takes into account the measured parameters of medium, the measurement method and means, compliance with BAT, measurement ranges and errors, estimated and warranty service life, mass and dimensional characteristics, and cost and complexity of maintenance, all serving for the convenience of selecting and implementing CEMS at thermal power plants. An example of the choice of measuring instruments from the proposed database for monitoring the marker pollutants emissions for the MPEI thermal power plant using the optimal choice algorithm is given.


2020 ◽  
Vol 71 (9) ◽  
pp. 125-142
Author(s):  
Claudia Maria Simonescu ◽  
Alina Melinescu ◽  
Culita Daniela Cristina ◽  
Dhuha Hasan ◽  
Bianca Zarnescu ◽  
...  

The aim of this research paper is to present a simple and efficient method to prepare zeolite materials from thermal power plant fly ash which is one of the most important waste resulted from power plants. The method of preparation of zeolite materials consists of alkaline activation followed by calcination at different temperatures. The zeolite materials prepared were studied by FT-IR spectroscopy, specific surface determination, X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM) and particle size composition. XRF data indicated that the zeolites synthesized are characterized by Si/Al ratio between 1.21 and 1.26, being mainly composed of Na-P1 zeolite. The optimum conditions of cadmium ions removal process by adsorption onto zeolite materials have been determined. It was concluded that increase of calcination temperature has as result increase of specific surface area and cosequently the increase of sorption capacity. An equilibrium, kinetic and thermodynamic study has been performed. The high value of correlation coefficient for the Langmuir isotherm reveals that the Cd(II) sorption onto zeolite materials occurs as a monolayer coverage of Cd(II) ions on homogenous zeolite surface. The pseudo-second-order kinetic model fits the experimental results of the Cd(II) sorption onto zeolite materials processes. As a results, the mechanism involved in Cd(II) sorption onto zeolite materials is based on chemical reactions. The thermodynamic results indicate that the Cd(II) adsorption process is more encouraging at higher temperatures.The results established that valuable NaP1 zeolite materials with high adsorption capacity can be prepared from thermal power plant fly ash through a simple method. The materials prepared can be utilized to remediate cadmium ions-bearing wastewater.


Author(s):  
Muhammad A. Raza ◽  
Krishan L. Khatri ◽  
Sunila Akbar ◽  
Muhammad I. U. Haque

In this paper, performance evaluation and technical audit of a 747 MW thermal power plant consisting of three generating units is conducted. The factors influencing the performance of the plant have been identified and improvements in processes and mechanical, electrical, instrumentation, and safety engineering are suggested. These improvements would result in better profitability, productivity, and performance. The paper further discusses technical issues and challenges and identifies key areas where improvements are possible. Future recommendation for the operation of the plant that would result in better throughput are also presented. The methodology of performance analysis presented in the paper will help improving operational efficiency of thermal power plants in developing countries.


2020 ◽  
Vol 5 ◽  
pp. 42-54
Author(s):  
Evgueny Boiko ◽  
Igor Polikarpov ◽  
Aleksey Bobrov ◽  
Sergey Sizintsov ◽  
Valeriy Volnev ◽  
...  

According to digital engineering, an intelligent digital infrastructure is intended to optimize performance of thermal power plants. This paper presents an intelligent digital approach to power facility management. As an example, Siberian Generating Company thermal power plants were considered. The authors have developed specialized software able to control and predict thermal power plant process equipment conditions comparing monitoring data and failure probabilities with appropriate mathematical models. Based on a life-cycle monitoring model, a management methodology was created to be applied to technical and business processes of a power facility to improve its maintenance strategy.


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