Hazardous elements in aqueous leachates of coal fly ash around thermal power plants disposal area

2020 ◽  
Vol 9 (10-12) ◽  
pp. 360
Author(s):  
Shyoraj Singh ◽  
Netra Pal Singh ◽  
Rekha Rani
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Disposal Area ◽  
Hazardous Elements

scholarly journals Composition and Morphology Characteristics of Magnetic Fractions of Coal Fly Ash Wastes Processed in High-Temperature Exposure in Thermal Power Plants

2019 ◽  
Vol 9 (9) ◽  
pp. 1964 ◽  
Author(s):  
Dinh-Hieu Vu ◽  
Hoang-Bac Bui ◽  
Bahareh Kalantar ◽  
Xuan-Nam Bui ◽  
Dinh-An Nguyen ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Combustion Process ◽  
Mineralogical Composition ◽  
Striking Difference ◽  
Thermal Power Plants ◽  
Power Stations ◽  
Magnetic Components

Coal-fired power stations are one of the primary sources of power generation in the world. This will produce considerable amounts of fly ash from these power stations each year. To highlight the potential environmental hazards of these materials, this study is carried out to evaluate the characterization of fly ashes produced in thermal power plants in northern Vietnam. Fly ash was firstly fractionated according to size, and the fractions were characterized. Then, each of these fractions was analyzed with regard to their mineralogical features, morphological and physicochemical properties. The analytical results indicate a striking difference in terms of the characteristics of particles. It was found that magnetic fractions are composed of magnetite hematite and, to a lower rate, mullite, and quartz. Chemical analyses indicate that the non-magnetic components mainly consist of quartz and mullite as their primary mineral phases. As the main conclusion of this research, it is found that the magnetic and non-magnetic components differ in terms of shape, carbon content and mineralogical composition. In addition, it was found that magnetic components can be characterized as more spheroidal components compared to non-magnetic ones. This comprehensive characterization not only offers a certain guideline regarding the uses of different ash fractions but it will also provide valuable information on this common combustion process.

scholarly journals Recent Advances in Methods for Recovery of Cenospheres from Fly Ash and Their Emerging Applications in Ceramics, Composites, Polymers and Environmental Cleanup

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1067
Author(s):  
Virendra Kumar Yadav ◽  
Krishna Kumar Yadav ◽  
Vineet Tirth ◽  
Ashok Jangid ◽  
G. Gnanamoorthy ◽  
...  
Keyword(s):  
Fly Ash ◽  
Mechanical Strength ◽  
Power Plants ◽  
Agricultural Land ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Value Added ◽  
Thermal Power Plants ◽  
Environmental Cleanup ◽  
High Mechanical Strength

Coal fly ash (CFA) is a major global pollutant produced by thermal power plants during the generation of electricity. A significant amount of coal fly ash is dumped every year in the near vicinity of the thermal power plants, resulting in the spoilage of agricultural land. CFA has numerous value-added structural elements, such as cenospheres, plerospheres, ferrospheres, and carbon particles. Cenospheres are spherical-shaped solid-filled particles, formed during the combustion of coal in thermal power plants. They are lightweight, have high mechanical strength, and are rich in Al-Si particles. Due to cenospheres’ low weight and high mechanical strength, they are widely used as ceramic/nanoceramics material, fireproofing material, and in nanocomposites. They are also used directly, or after functionalization, as an adsorbent for environmental cleanup—especially for the removal of organic and inorganic contaminants from wastewater. By utilizing this waste material as an adsorbent, the whole process becomes economical and eco-friendly. In this review, we have highlighted the latest advances in the cenospheres recovery from fly ash and their application in ceramics and wastewater treatment.

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.

TRACE ELEMENT ANALYSIS OF FLY ASH BY PIXE

1999 ◽  
Vol 09 (03n04) ◽  
pp. 417-422 ◽  
Author(s):  
V. VIJAYAN ◽  
S. N. BEHERA
Keyword(s):  
Fly Ash ◽  
Trace Element ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Trace Element Analysis ◽  
Chemical Properties ◽  
Solid Material ◽  
Thermal Power Plants ◽  
Element Analysis

Fly ash is a major component of solid material generated by the coal-fired thermal power plants. In India the total amount of fly ash produced per annum is around 100 million tonnes. Fly ash has a great potential for utilization in making industrial products such as cement, bricks as well as building materials, besides being used as a soil conditioner and a provider of micro nutrients in agriculture. However, given the large amount of fly ash that accumulate at thermal power plants, their possible reuse and dispersion and mobilization into the environment of the various elements depend on climate, soils, indigenous vegetation and agriculture practices. Fly ash use in agriculture improved various physico-chemical properties of soil, particularly the water holding capacity, porosity and available plant nutrients. However it is generally apprehended that the application of large quantity of fly ash in fields may affect the plant growth and soil texture. Hence there is a need to characterize trace elements of fly ash. The results of trace element analysis of fly ash and pond ash samples collected from major thermal power plants of India by Particle Induced X-ray Emission (PIXE) have been discussed.

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Combustion ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Power Stations ◽  
Thermal Power Stations ◽  
Coal Ashes ◽  
By Products

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

RESEARCH OF COMPLEX MODIFICATION OF HEAVY CONCRETE

2021 ◽  
Vol 96 (4) ◽  
pp. 107-112
Author(s):  
YU.S. FILIMONOVA ◽  
◽  
E.G. VELICHKO ◽  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Complex Chemical ◽  
Composition And Structure ◽  
Combined Use ◽  
Mineral Additive

Modification of the composition and structure of heavy concrete with the use of a complex chemical-mineral additive consisting of fly ash from thermal power plants, a superplasticizer, a high-valence hardening accelerator AC and a fine-dispersed clinker component is considered. Modified concrete is characterized by an increase in compressive strength at a brand age by 67%, a decrease in the water content of a concrete mixture by 13.6% and an improvement in its workability by 11-12 cm. With the combined use of a superplasticizer and a high-valence hardening accelerator AC a significant synergistic effect is observed in the format of enhancing their plasticizing effect. The high efficiency of the application of the mixed-dispersed clinker component has been established.

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