scholarly journals Critical Elements in Fly Ash from the Combustion of Bituminous Coal in Major Polish Power Plants

2018 ◽  
Vol 35 ◽  
pp. 02003 ◽  
Author(s):  
Barbara Bielowicz ◽  
Dariusz Botor ◽  
Jacek Misiak ◽  
Marian Wagner
Keyword(s):  
Fly Ash ◽  
Enrichment Factor ◽  
Power Plants ◽  
Bituminous Coal ◽  
Thermal Power ◽  
Sedimentary Rocks ◽  
Coal Ash ◽  
Average Concentration ◽  
Global Average ◽  
Critical Elements

The concentration of critical elements, including such REE as Fe, Co, W, Zn, Cr, Ni, V, Mn, Ti, Ag, Ga, Ta, Sr, Li, and Cu, in the so-called fly ash obtained from the 9 Polish power plants and 1 thermal power station has been determined. The obtained values, compared with the global average concentration in bituminous coal ash and sedimentary rocks (Clarke values), have shown that the enrichment of fly ash in the specified elements takes place in only a few bituminous coal processing sites in Poland. The enrichment factor (EF) is only slightly higher (the same order of magnitude) than the Clarke values. The enrichment factor in relation to the Clarke value in the Earth’s crust reached values above 10 in all of the examined ashes for the following elements: Cr, Ni, V, W, and, in some ash samples, also Cu and Zn. The obtained values are low, only slightly higher than the global average concentrations in sedimentary rocks and bituminous coal ashes. The ferromagnetic grains (microspheres) found in bituminous coal fly ashes seem to be the most economically prospective in recovery of selected critical elements. The microanalysis has shown that iron cenospheres and plerospheres in fly ash contain, in addition to enamel and iron oxides (magnetite and hematite), iron spinels enriched in Co, Cr, Cu, Mn, Ni, W, and Zn.

POSSIBLE USE OF FLY ASH IN CERAMIC INDUSTRIES: AN INNOVATIVE METHOD TO REDUCE ENVIRONMENTAL POLLUTION

2013 ◽  
Vol 22 ◽  
pp. 99-102 ◽  
Author(s):  
GAYATRI SHARMA ◽  
S. K. MEHLA ◽  
TARUN BHATNAGAR ◽  
ANNU BAJAJ
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Fine Particles ◽  
Thermal Power ◽  
Coal Ash ◽  
Natural Soil ◽  
Thermal Power Plants ◽  
Silica Alumina ◽  
Near Future ◽  
Land Water

The process of coal combustion results in coal ash, 80% of which is very fine in nature & is thus known as fly ash. Presently, in India, about 120 coal based thermal power plants are producing about 90-120 million tons of fly ash every year. With increase in demand of power energy, more and more thermal power plants are expected to commission in near future and it is expected that fly ash generation will be 225 million tons by 2017. Disposal of fly ash requires large quantity of land, water and energy and its fine particles, if not disposed properly, by virtue of their weightless, can become air born and adversely affect the entire Environment. These earth elements primarily consist of silica, alumina & iron etc. and its physicochemical parameters are closely resembles with volcanic ash, natural soil etc. These properties, therefore, makes it suitable for use in ceramic industries and helps in saving the environment and resources.

scholarly journals Coal Fly Ash Ceramics: Preparation, Characterization, and Use in the Hydrolysis of Sucrose

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ricardo Pires dos Santos ◽  
Jorge Martins ◽  
Carlos Gadelha ◽  
Benildo Cavada ◽  
Alessandro Victor Albertini ◽  
...  
Keyword(s):  
Fly Ash ◽  
Surface Area ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Coal Ash ◽  
Mineralogical Composition ◽  
Degree Of Hydrolysis ◽  
High Degree ◽  
Hydrolysis Of

Coal ash is a byproduct of mineral coal combustion in thermal power plants. This residue is responsible for many environmental problems because it pollutes soil, water, and air. Thus, it is important to find ways to reuse it. In this study, coal fly ash, obtained from the Presidente Médici Thermal Power Plant, was utilized in the preparation of ceramic supports for the immobilization of the enzyme invertase and subsequent hydrolysis of sucrose. Coal fly ash supports were prepared at several compaction pressures (63.66–318.30 MPa) and sintered at 1200°C for 4 h. Mineralogical composition (by X-ray diffraction) and surface area were studied. The ceramic prepared with 318.30 MPa presented the highest surface area (35 m2/g) and amount of immobilized enzyme per g of support (76.6 mg/g). In assays involving sucrose inversion, it showed a high degree of hydrolysis (around 81%) even after nine reuses and 30 days’ storage. Therefore, coal fly ash ceramics were demonstrated to be a promising biotechnological alternative as an immobilization support for the hydrolysis of sucrose.

scholarly journals CONVERSION OF COAL FLY ASH TO ZEOLITE-BASED IRON OXIDE MAGNETIC NANOCOPOSITES BY MODIFIED FUSION-HYDROTHERMAL SYNTHESIS

2020 ◽  
pp. 30-35
Author(s):  
Silviya Boycheva ◽  
Denitza Zgureva
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Fly Ash ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Coal Ash ◽  
Low Temperature Processing ◽  
Oxide Phases ◽  
Stage Synthesis

Coal fly ash generated in Thermal Power Plants is utilized for synthesis of zeolites due to its aluminosilicate composition. The highest degree of zeolitization of coal ash in a particular zeolite phase is achieved by double-stage synthesis involving successive alkaline melting and hydrothermal activation of the reaction mixtures, while the uniform distribution of the iron oxides transferred from the raw coal ash is ensured by ultrasonic treatment. However, the applied melting step results in the oxidation of the magnetic iron oxide phases to non-magnetic ones, which results in the loss of magnetic properties of the resulting materials. The present investigation focuses on an improved double- stage synthesis procedure by the addition of raw coal ash containing magnetite between high temperature and low temperature processing. In this way, the magnetic phase is retained in the final product and the magnetic properties of the zeolites are preserved, which is important for their application in the adsorption of pollutants from wastewater.

Fly Ash-Based Geopolymer: Green Material in Carbon-Constrained Society

2021 ◽  
Vol 321 ◽  
pp. 65-71
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Bottom Ash ◽  
Coal Ash ◽  
Raw Material ◽  
Engineering Properties ◽  
Gravimetric Analysis ◽  
Green Materials ◽  
Alumino Silicate

Climate change is recognized as a global problem and even the industrial and construction sectors are trying to reduce the green-house gas emissions, especially on CO2 emissions. In Vietnam, the coal-fired thermal power plants are discharging millions of tons of CO2 and coal ash annually. This coal ash is comprised of about 80% of fly ash and the rest is bottom ash. This study would like to introduce one of the potential solutions in a carbon-constrained society that would not only manage the fly ash but also utilized this as raw material for green materials through geopolymerization. The geopolymer-based material has lower energy consumption, minimal CO2 emissions and lower production cost as it valorizes industrial waste. The fly ash containing high alumino-silicate resources from a coal-fired power plant in Vietnam was mixed with sodium silicate and sodium hydroxide solutions to obtain the geopolymeric pastes. The pastes were molded in 10x10x20cm molds and then cured at room temperature for 28 days. The 28-day geopolymer specimens were carried out to test for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). The microstructure analysis was also conducted for this eco-friendly materials using X ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Differential Thermal Analysis - Thermal Gravimetric Analysis (DTA-TGA).

Zinc Oxide Recovery from Solid Waste of Electric Arc Furnace Dust (EAFD) Using Hydrometallurgical Method

2020 ◽  
Vol 849 ◽  
pp. 108-112
Author(s):  
Widi Astuti ◽  
Agus Haerudin ◽  
Istihanah Nurul Eskani ◽  
Fajar Nurjaman ◽  
Aulia Pertiwi Tri Yuda ◽  
...  
Keyword(s):  
Fly Ash ◽  
Enrichment Factor ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Bottom Ash ◽  
Coal Ash ◽  
Atomic Emission ◽  
Xrd Analysis ◽  
Unburned Carbon ◽  
Amorphous Glass

Indonesia coal ash is predicted to reach 10.8 million tons in the year 2020 but its utilization is still limited. In the last decade, coal ash has become a promising REY source candidate. To determine the potency of REY in Indonesia coal ash, information about element concentration and mineralogy of the ash is essential. In this study, coal ash samples were taken from Paiton-2, Pacitan, Rembang, and Tanjung Jati coal-fired power plants. Element content and mineralogy were analyzed using Inductive Couple Plasma Mass Spectroscopy/Atomic Emission Spectroscopy (ICP-MS/AES), X-Ray Diffractometer (XRD) and petrographic. The results showed that coal fly ash and bottom ash contains critical REY in the range of 38% to 41% with Coutlook larger than one. XRD analysis showed that both fly ash and bottom ash have similar mineral phases with slightly different concentrations. The mineral phase is dominated by amorphous glass, quartz, Fe-bearing minerals, and unburned carbon. The amorphous glass phase in fly ash is in the range of 23 to 34% while in bottom ash between 14 and 34%. Unburned carbon content in fly ash and bottom ashes are 7-13% and 7-19%, respectively. Fe-bearing mineral content in fly ash is 15-20% and bottom ash is 13-20%. In addition, Indonesia coal ash has a higher Heavy-REY enrichment factor than Light-REY. The Enrichment Factor of HREY in fly ash is as much as 1.3 times (in average) of the bottom ash.

scholarly journals Processing of high-grade zeolite nanocomposites from solid fuel combustion by-products as critical raw materials substitutes

2020 ◽  
Vol 7 ◽  
pp. 22
Author(s):  
Silviya Boycheva ◽  
Denitza Zgureva ◽  
Hristina Lazarova ◽  
Katerina Lazarova ◽  
Cyril Popov ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Raw Materials ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Coal Ash ◽  
High Grade ◽  
Fly Ash Zeolite ◽  
By Products ◽  
Critical Raw Materials

High-grade zeolite nanocomposites are synthesized utilizing solid by-products from combustion of coal for energy production in Thermal Power Plants applying alkaline aging, hydrothermal and fusion-hydrothermal activation procedures. The obtained coal ash zeolites were studied with respect to their chemical and phase composition, morphology, surface parameters and thermal properties. It was found that they are distinguished in nanocrystalline morphology and significant content of iron oxide nanoparticles (γ-Fe2O3, α-Fe2O3, γ-Fe3O4) and doping elements (Cu, Co, Mn, V, W, etc.) transferred from the raw coal ash, and therefore they are assumed as nanocomposites. Coal fly ash zeolite nanocomposites are characterized by a mixed micro-mesoporous texture, significant concentration of acidic Brønsted centers due to their high surface insaturation, high chemical and thermal stabilty. This unique combination of compositional and textural properties predetermines the application of these materials as catalysts for thermal oxidation processes, anticorrosion barrier coatings, carbon capture adsorbents, matrices for hosting functional groups, detergents etc. Examples for coal fly ash zeolite applications for substitution of critical raw materials in practice are provided.

Potency of Rare Earth Elements and Yttrium in Indonesia Coal Ash

2020 ◽  
Vol 849 ◽  
pp. 102-107
Author(s):  
Widya Rosita ◽  
Dea Anisa Ayu Besari ◽  
I Made Bendiyasa ◽  
Indra Perdana ◽  
Ferian Anggara ◽  
...  
Keyword(s):  
Fly Ash ◽  
Enrichment Factor ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Bottom Ash ◽  
Coal Ash ◽  
Atomic Emission ◽  
Xrd Analysis ◽  
Unburned Carbon ◽  
Amorphous Glass

Indonesia coal ash is predicted to reach 10.8 million tons in the year 2020 but its utilization is still limited. In the last decade, coal ash has become a promising REY source candidate. To determine the potency of REY in Indonesia coal ash, information about element concentration and mineralogy of the ash is essential. In this study, coal ash samples were taken from Paiton-2, Pacitan, Rembang, and Tanjung Jati coal-fired power plants. Element content and mineralogy were analyzed using Inductive Couple Plasma Mass Spectroscopy/Atomic Emission Spectroscopy (ICP-MS/AES), X-Ray Diffractometer (XRD) and petrographic. The results showed that coal fly ash and bottom ash contains critical REY in the range of 38% to 41% with Coutlook larger than one. XRD analysis showed that both fly ash and bottom ash have similar mineral phases with slightly different concentrations. The mineral phase is dominated by amorphous glass, quartz, Fe-bearing minerals, and unburned carbon. The amorphous glass phase in fly ash is in the range of 23 to 34% while in bottom ash between 14 and 34%. Unburned carbon content in fly ash and bottom ashes are 7-13% and 7-19%, respectively. Fe-bearing mineral content in fly ash is 15-20% and bottom ash is 13-20%. In addition, Indonesia coal ash has a higher Heavy-REY enrichment factor than Light-REY. The Enrichment Factor of HREY in fly ash is as much as 1.3 times (in average) of the bottom ash.

scholarly journals Concrete Mix Design by Partial Surrogation of Conventional Aggregates with Fabrigated Aggregates

2020 ◽  
Vol 9 (3) ◽  
pp. 1-10
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
18Th Century ◽  
Thermal Power ◽  
Coal Ash ◽  
Large Space ◽  
Concrete Mix Design ◽  
Long Time ◽  
Complicated Task ◽  
Early 18Th Century

Since the invention of concrete in the early 18th century, there has been a constant rise in efforts to increase the productivity of this material so that it becomes more economical. The economy of concrete also depends on the use of products that are abundantly available in the near vicinity, at the least processing costs. One such material is the coal ash. It is an unavoidable residual yield of the thermal power plants which are the major electricity producers in India. The 120 power plants produce 120-150 million tons of fly ash per year. The disposal of this fly ash is a complicated task as it takes a very large space to dump, also this causes air pollution and harmful health conditions when inhaled. Many attempts have been made to utilize this material in the recent past. One such attempt is the use of fly ash in concrete. Is has been found that fly ash can be used as an important constituent of concrete in the form of aggregates. The market for fly ash aggregate has one of the most intriguing opportunity for business owners as use of fly ash has no seasonal problems, as it could be stored for a very long time in open surroundings without the risk of losses, environmental hazard or freeze-thaw condition complications. The use of fly ash aggregates is a very good application for the disposal of fly ash.

A Review on Utilization of Fly- Ash and Pond-Ash as a Partial Replacement of Cement in Concrete Mix Design

2018 ◽  
pp. 413-418
Author(s):  
Harshkumar Patel ◽  
Yogesh Patel
Keyword(s):  
Fly Ash ◽  
Electricity Generation ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Strength Test ◽  
Partial Replacement ◽  
Pond Ash ◽  
Research Activities ◽  
Ash Disposal

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.

scholarly journals Preparation of Synthetic Zeolites from Coal Fly Ash by Hydrothermal Synthesis

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1267
Author(s):  
David Längauer ◽  
Vladimír Čablík ◽  
Slavomír Hredzák ◽  
Anton Zubrik ◽  
Marek Matik ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Product Analysis ◽  
Coal Combustion Products ◽  
X Ray ◽  
Wide Range ◽  
Silica Alumina

Large amounts of coal combustion products (as solid products of thermal power plants) with different chemical and physical properties cause serious environmental problems. Even though coal fly ash is a coal combustion product, it has a wide range of applications (e.g., in construction, metallurgy, chemical production, reclamation etc.). One of its potential uses is in zeolitization to obtain a higher added value of the product. The aim of this paper is to produce a material with sufficient textural properties used, for example, for environmental purposes (an adsorbent) and/or storage material. In practice, the coal fly ash (No. 1 and No. 2) from Czech power plants was firstly characterized in detail (X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), particle size measurement, and textural analysis), and then it was hydrothermally treated to synthetize zeolites. Different concentrations of NaOH, LiCl, Al2O3, and aqueous glass; different temperature effects (90–120 °C); and different process lengths (6–48 h) were studied. Furthermore, most of the experiments were supplemented with a crystallization phase that was run for 16 h at 50 °C. After qualitative product analysis (SEM-EDX, XRD, and textural analytics), quantitative XRD evaluation with an internal standard was used for zeolitization process evaluation. Sodalite (SOD), phillipsite (PHI), chabazite (CHA), faujasite-Na (FAU-Na), and faujasite-Ca (FAU-Ca) were obtained as the zeolite phases. The content of these zeolite phases ranged from 2.09 to 43.79%. The best conditions for the zeolite phase formation were as follows: 4 M NaOH, 4 mL 10% LiCl, liquid/solid ratio of 30:1, silica/alumina ratio change from 2:1 to 1:1, temperature of 120 °C, process time of 24 h, and a crystallization phase for 16 h at 50 °C.

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