Stabilization of Expansive Soil with Thermal Power Plant Waste (Fly Ash and Coal Bottom Ash)—A Review

Navagire, Omkar Prakash; Sharma, S. K.; Rambabu, Dadi

doi:10.1007/978-3-030-96554-9_21

Cited by 2 publications

(1 citation statement)

References 18 publications

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“…In addition, the CA obtained in pulverized coal boilers at T > 1100 • C transforms the aluminosilicates in coal into mullite, which can be dissolved in acid using hydrometallurgical methods only in a high-pressure reactor [5]. CA is also divided into bottom ash and fly ash-a fine fraction of ash, which is carried away with waste gases [6,7]. CFA yields more than 80%, and its fine composition eliminates the need for additional milling, so many studies have focused on extracting alumina from the fly ash [8,9].…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Aluminum and Scandium Extraction from Desilicated Coal Fly Ash by High-Pressure HCl Leaching

Shoppert,

Valeev,

Loginova

2023

Metals

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Coal fly ash (CFA) is a waste that forms via coal combustion in thermal power stations. CFA consists of numerous components, whose recovery can address environmental and resource concerns associated with sustainable development. Most of the alumina (Al2O3) and rare-earth elements (REEs) in CFA are contained in the amorphous glassy mass and in the refractory mullite phase (3Al2O3·SiO2), which can be dissolved only using high-pressure acid leaching (HPAL). In this paper, the method of preactivation of CFA by treatment with a highly concentrated NaOH solution is used to increase the efficiency of Al and Sc extraction during HPAL. This method allows for the elimination of an inert aluminosilicate layer from the surface of mullite, transferring the REEs into an acid-soluble form. The Al and Sc extraction can reach 80% after HCl HPAL at T = 170 °C and a 90 min duration. According to the kinetic data, the dissolution of Al follows the surface chemical reaction and intraparticle diffusion shrinking core models in the initial and later stages of leaching, respectively. A high activation energy of 52.78 kJ mol−1 was observed at low temperatures, and a change in the mechanism occurred after 170 °C when the activation energy decreased to 26.34 kJ mol–1. The obtained activation energy value of 33.51 kJ mol−1 for Sc leaching indicates that diffusion has a strong influence at all studied temperatures. The residue was analysed by SEM-EDX, XRF, BET, and XRD methods in order to understand the mechanism of DCFA HPAL process.

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Section: Introductionmentioning

confidence: 99%

Kinetics of Aluminum and Scandium Extraction from Desilicated Coal Fly Ash by High-Pressure HCl Leaching

Shoppert,

Valeev,

Loginova

2023

Metals

View full text Add to dashboard Cite

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Engineering Properties of Expansive Clay Soils with Sustainable Stabilization Methods

Navagire,

V.,

Sharma

2024

Preprint

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The production of Industrial waste is increasing day by day in many countries around the world. One of the industrial wastes is Coal Bottom Ash (CBA) which is a coal combustion by-product of thermal power plants, which is categorized as creating environmental pollution if it is not disposed of properly. The objective of the present study is to evaluate the compressive strength and bearing capacity of Black Cotton (BC) soil/Subgrade soil by conducting the Unconfined Compressive Strength (UCS) test and California Bearing Ratio (CBR) test. In the present study, a total of 20 combinations of mix proportions were prepared using the following materials: BC soil, Coal Bottom Ash (CBA), and Wollastonite Microfiber (WMF). The mix proportions involved replacing BC soil with (10%, 20%, 30%, and 40%) CBA and (5%, 10%, and 15%) WMF. Samples were prepared by following the curing process for up to 28 days for UCS testing. The results of standard Proctor tests reveal that the addition of CBA and WMF leads to a decrease in the Optimum Moisture Content (OMC) and an increase in the Maximum Dry Density (MDD). It is also observed that the swelling of the soil reduces drastically with the addition of CBA and WMF mixture. Engineering behaviour delineates the corresponding increase in UCS and CBR values with the increase in mix proportions of CBA-WMF mixes. Assessment of the UCS and CBR values confirms that the utilisation of the CBA and the WMF in Subgrade soil stabilisation provides improved engineering behaviour to deploy in several construction applications.

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Stabilization of Expansive Soil with Thermal Power Plant Waste (Fly Ash and Coal Bottom Ash)—A Review

Cited by 2 publications

References 18 publications

Kinetics of Aluminum and Scandium Extraction from Desilicated Coal Fly Ash by High-Pressure HCl Leaching

Kinetics of Aluminum and Scandium Extraction from Desilicated Coal Fly Ash by High-Pressure HCl Leaching

Engineering Properties of Expansive Clay Soils with Sustainable Stabilization Methods

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