Abstract
In this study, the features of fly ashes originating from industrial-scale high volatile bituminous coal combustion and co-combustion of coal with 10% admixture of alternative fuel SRF (solid recovered fuel) are presented, with emphasis on the organic petrographical characteristics. The organic petrographical and mineralogical data are co-evaluated with geochemical data, with the aim to provide a full classification of the studied fly ashes, as well as base information toward any potential application of this waste material, according to the recycling economy principles. By applying organic petrographical methods, the assignment of the carbon-rich residuals to the respective feed fuel, either coal or SRF, can be achieved. The obtained quantitative evaluation provides useful information regarding the combustion conditions in the stoker boiler. The analyzed fly ashes contain significant C-residuals, mostly in the form of fused, dense, and anisotropic particles, while the enrichment in sooty particles is caused due to the addition of SRF fuel. In conjunction with the moderate-low content of potential hazardous elements, the features of the contained C-residual phases suggest that these fly ashes could possibly be the subject of further studies for their applicability as soil improvements.
Highlights
Fly ashes are dusty materials collected from flue gas that usually exhibit very uniform grain distribution, comprised mainly by an amorphous and crystalline inorganic fraction and unburned carbon-rich particles (C-residues), e.g., [1,2,3,4]
A notable feature of both fly ashes is the significant amount of un-combusted organic fraction, accounting for 29% and 33% for the FA(HC) and FA(SRF), respectively (Table 2)
Iron oxides contributed with ~9%, whereas CaO was less than 9%, with the higher value in FA(SRF) sample
Summary
Fly ashes are dusty materials collected from flue gas that usually exhibit very uniform grain distribution, comprised mainly by an amorphous and crystalline inorganic fraction and unburned carbon-rich particles (C-residues), e.g., [1,2,3,4]. Most of the countries that utilize coal for power production face the problem of managing the large quantities of fly ashes that are annually produced. Apart from the obvious solution of burying fly ashes into the depleted excavations during rehab, a significant industrial stream has been developed within the last decades to utilize this material in various applications, contributing toward recycling solutions. A significant amount of research has been conducted regarding the application of fly ashes in replacing other materials in the fields of agricultural soils bio-amelioration and industrial wastes treatment in an effort to reduce the environmental footprint of coal utilization, e.g., [9,10,11]. Depending on the properties of the fly ashes, these wastes can be utilized in different fields
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
