Effect of zeolitization on physicochemico-mineralogical and geotechnical properties of lagoon ash

2001 ◽  
Vol 38 (5) ◽  
pp. 1105-1112 ◽  
Author(s):  
P K Kolay ◽  
D N Singh
Keyword(s):  
Chemical Composition ◽  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Power Plants ◽  
Thermal Power ◽  
Geotechnical Properties ◽  
Thermal Power Plants ◽  
Controlled Experiments ◽  
Water Interaction ◽  
Geotechnical Characteristics

A common method to dispose of ash generated from coal-fired thermal power plants is to mix the ash with water and place the ash–water slurry in ponds or lagoons. Such a disposal system allows for the ash–water interaction. Alkalis present in the ash react with water, leading to zeolitization of the ash and changes in its overall properties. To simulate such interaction, controlled experiments have been conducted on a typical Indian lagoon ash, and the effect of zeolitization on the physicochemico–mineralogical properties has been studied. The effect of zeolitization on the geotechnical properties of the ash has also been investigated in detail. It is believed that such investigations are essential for bulk utilization of the lagoon ash, particularly as a fill material, where properties like compaction, consolidation, and hydraulic conductivity are very important.Key words: lagoon ash, physical properties, chemical composition, mineralogy, geotechnical characteristics, zeolitization.

scholarly journals Geotechnical Characteristics of HNPC Fly Ash

2020 ◽  
Vol 9 (5) ◽  
pp. 2007-2012
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Morphological Characteristics ◽  
Geotechnical Properties ◽  
Thermal Power Plants ◽  
Geotechnical Characteristics ◽  
Polyester Fibers ◽  
Ft Ir

Fly ash is the solid waste being produced in largest quantities from thermal power plants in India causing pollution of land and water. It requires bulk utilization which is possible in geotechnical applications such as embankments and subgrades. This necessitates the determination of the geotechnical properties of fly ash from different thermal power plants. The present paper investigates the geotechnical characteristics of fly ash from HNPC, Pedagantyada, Visakhapatnam. The physical and index properties of HNPC Fly ash (HNFA) and its OMC and MDD using I.S. Heavy compaction are first determined. The shear strength, CBR and permeability are then determined at OMC. The study also investigates the influence of polyester fibers and lime as admixture to HNFA in different percentages on Compaction and CBR properties to check their effectiveness in improving HNFA for use in embankments and subgrade. The chemical and morphological characteristics of HNFA, including its specific surface, XRD, SEM and FT-IR spectra have also been determined. The study confirms the suitability of HNFA for use in geotechnical applications and verifies the relative suitability of polyester and lime as admixtures for further improvement of the geotechnical properties of HNFA

scholarly journals Prerequisites for developing an advanced welding technology for repair of worn elements of steam-conducting systems

2021 ◽  
pp. 108
Author(s):  
Tatyana Syrenko
Keyword(s):  
Chemical Composition ◽  
Welded Joints ◽  
Power Plants ◽  
Thermal Power ◽  
Economic Effect ◽  
Thermal Power Plants ◽  
Repair Work ◽  
Welding Technology ◽  
Conducting Path ◽  
Mechanized Welding

The main disadvantage of standard technologies of welding steam pipelines of thermal power plants is that they can allow the presence of defective structures close to the defective ones in the metal of the seam and in the sections of the HAZ. In this regard, the question arises about the development of a new technology that will provide the appropriate structure and properties that will increase the service life of steam pipelines and get a significant economic effect. Goal. The goal is improvement of the technology of welding pipelines of thermal power plants based on the study of the features of the formation of welded joints operating in Creep conditions. Methodology. The level of wear of the elements of the Steam-conducting path was estimated taking into account the provisions of the regulatory documentation of metallographic analysis, determination of chemical composition and properties, as well as the degree of their deformation. Results. It is revealed that welded joints are characterized by initial structural heterogeneity, which is closely related to long-term strength, ductility and impact strength. For example, at different sections of a welded joint, there is a different intensity of transition of alloying elements and, accordingly, a different type of structural component can be formed. The proposed technology of welding repair of damaged elements of steam pipelines using mechanized welding in CO2+Ar provides for the production of welded joints with a higher level of uniformity of structure, chemical composition and properties. Scientific novelty and practical significance. The welding technology has been improved, which includes developing the modes for performing repair work by mechanized welding in an Ar + CO2 environment of steam pipeline samples with a depth of ≥ 20 mm and a width of ≥ 30 mm, and differs from the known ones by using linear energy welding of 1.2–1.5 MJ/m.

On the prospect of introduction of plasma ignition in power boilers

2019 ◽  
Vol 12 (1) ◽  
pp. 22-28
Author(s):  
V. Ye. Mikhailov ◽  
S. P. Kolpakov ◽  
L. A. Khomenok ◽  
N. S. Shestakov
Keyword(s):  
Russian Federation ◽  
Solid Fuel ◽  
Power Plants ◽  
Thermal Power ◽  
Fuel Oil ◽  
Solid Fuels ◽  
Thermal Power Plants ◽  
Plasma Ignition ◽  
The Russian Federation ◽  
Capital Construction

One of the most important issues for modern domestic power industry is the creation and further widespread introduction of solid propellant energy units for super-critical steam parameters with high efficiency (43–46%) and improved environmental parameters. This will significantly reduce the use of natural gas.At the same time, one of the major drawbacks of the operation of pulverized coal power units is the need to use a significant amount of fuel oil during start-up and shutdown of boilers to stabilize the burning of the coal torch in the variable boiler operating modes.In this regard, solid fuel TPPs need to be provided with fuel oil facilities, with all the associated problems to ensure the performance (heating of fuel oil in winter), reliability and safety. All of the above problems increase both the TPP capital construction costs, and the electricity generating cost.A practical solution to the above problems at present is the use of a plasma technology for coal torch ignition based on thermochemical preparation of fuel for combustion. The materials of the developments of JSC “NPO CKTI” on application of plasmatrons in boilers of thermal power plants at metallurgical complexes of the Russian Federation are also considered.Plasma ignition systems for solid fuels in boilers were developed by Russian specialists and were introduced at a number of coal-fi red power plants in the Russian Federation, Mongolia, North Korea, and Kazakhstan. Plasma ignition of solid fuels is widely used in China for almost 30% of power boilers.The introduction of plasma-energy technologies will improve the energy efficiency of domestic solid-fuel thermal power plants and can be widely implemented in the modernization of boilers.During the construction of new TPPs, the construction of fuel oil facilities can be abandoned altogether, which will reduce the capital costs of the construction of thermal power plants, reduce the construction footprint, and increase the TPP safety.

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