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Title: Advanced Multi-Product Coal Utilization By-Product Processing Plant

Abstract

The objective of the project is to build a multi-product ash beneficiation plant at Kentucky Utilities 2,200-MW Ghent Generating Station, located in Carroll County, Kentucky. This part of the study includes an investigation of the secondary classification characteristics of the ash feedstock excavated from the lower ash pond at Ghent Station. The secondary classification testing was concluded using a continuous demonstration-scale lamella classifier that was operated at a feed rate of 0.3 to 1.5 tons/hr. Feed to the secondary classifier was generated by operating the primary classifier at the conditions shown to be effective previously. Samples were taken while the secondary classifier was operated under a variety of conditions in order to determine the range of conditions where the unit could be efficiently operated. Secondary classification was effective for producing an ultra-fine ash (UFA) product. Inclined lamella plates provided an effective settling surface for coarser ash particles and plate spacing was shown to be an important variable. Results showed that the closer the plate spacing, the finer the size distribution of the UFA product. Flotation of the secondary classifier feed provided a lower LOI UFA product (2.5% LOI vs. 4.5% LOI) and a dispersant dosage of 2 to 2.5 g/kgmore » was adequate to provide UFA grade (3.8 to 4.4 {micro}m) and recovery (53 to 68% 5{micro}m recovery). The UFA yield without flotation was {approx}33% and lower ({approx}20%) with flotation. Demonstration plant product evaluations showed that water requirements in mortar were reduced and 100% of control strength was achieved in 28 days for the coarser products followed by further strength gain of up to 130% in 56 days. The highest strengths of 110% of control in 7 days and 140% in 56 days were achieved with the finer products. Mortar air requirements for processed products were essentially the same as those for standard mortar, suggesting that the unburned carbon remaining does not have an affinity for air entraining admixture (AEA), a consideration that is a significant benefit. In concrete, substitution of 20% showed that the UFA product outperformed a typical ash by achieving 105 to 107% of control strength after 28 days and 109.5 to 112% after 56 days. Higher substitution levels were shown to delay early strength development, but surpass control strength after 28 days while lower substitution levels provide both early and longer term strength. One of the most significant benefits provided by using UFA in concrete mix designs is the improved resistance to chloride permeability while some improvements is flexural strength were realized and tensile strength was essentially unchanged. Potentially significant benefits may also be offered by using UFA as a process addition in the manufacture of cement clinker.« less

Authors:
; ;
Publication Date:
Research Org.:
Univ. of Kentucky, Lexington, KY (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
886683
DOE Contract Number:  
FC26-05NT41781
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; AFFINITY; BY-PRODUCTS; CARBON; CEMENTS; CHLORIDES; CLASSIFICATION; COAL; CONCRETES; DEMONSTRATION PLANTS; FLEXURAL STRENGTH; FLOTATION; MORTARS; PERMEABILITY; PONDS; PROGRESS REPORT; TENSILE PROPERTIES; TESTING; WATER REQUIREMENTS

Citation Formats

Groppo, John, Robl, Thomas, and Rathbone, Robert. Advanced Multi-Product Coal Utilization By-Product Processing Plant. United States: N. p., 2006. Web. doi:10.2172/886683.
Groppo, John, Robl, Thomas, & Rathbone, Robert. Advanced Multi-Product Coal Utilization By-Product Processing Plant. United States. https://doi.org/10.2172/886683
Groppo, John, Robl, Thomas, and Rathbone, Robert. 2006. "Advanced Multi-Product Coal Utilization By-Product Processing Plant". United States. https://doi.org/10.2172/886683. https://www.osti.gov/servlets/purl/886683.
@article{osti_886683,
title = {Advanced Multi-Product Coal Utilization By-Product Processing Plant},
author = {Groppo, John and Robl, Thomas and Rathbone, Robert},
abstractNote = {The objective of the project is to build a multi-product ash beneficiation plant at Kentucky Utilities 2,200-MW Ghent Generating Station, located in Carroll County, Kentucky. This part of the study includes an investigation of the secondary classification characteristics of the ash feedstock excavated from the lower ash pond at Ghent Station. The secondary classification testing was concluded using a continuous demonstration-scale lamella classifier that was operated at a feed rate of 0.3 to 1.5 tons/hr. Feed to the secondary classifier was generated by operating the primary classifier at the conditions shown to be effective previously. Samples were taken while the secondary classifier was operated under a variety of conditions in order to determine the range of conditions where the unit could be efficiently operated. Secondary classification was effective for producing an ultra-fine ash (UFA) product. Inclined lamella plates provided an effective settling surface for coarser ash particles and plate spacing was shown to be an important variable. Results showed that the closer the plate spacing, the finer the size distribution of the UFA product. Flotation of the secondary classifier feed provided a lower LOI UFA product (2.5% LOI vs. 4.5% LOI) and a dispersant dosage of 2 to 2.5 g/kg was adequate to provide UFA grade (3.8 to 4.4 {micro}m) and recovery (53 to 68% 5{micro}m recovery). The UFA yield without flotation was {approx}33% and lower ({approx}20%) with flotation. Demonstration plant product evaluations showed that water requirements in mortar were reduced and 100% of control strength was achieved in 28 days for the coarser products followed by further strength gain of up to 130% in 56 days. The highest strengths of 110% of control in 7 days and 140% in 56 days were achieved with the finer products. Mortar air requirements for processed products were essentially the same as those for standard mortar, suggesting that the unburned carbon remaining does not have an affinity for air entraining admixture (AEA), a consideration that is a significant benefit. In concrete, substitution of 20% showed that the UFA product outperformed a typical ash by achieving 105 to 107% of control strength after 28 days and 109.5 to 112% after 56 days. Higher substitution levels were shown to delay early strength development, but surpass control strength after 28 days while lower substitution levels provide both early and longer term strength. One of the most significant benefits provided by using UFA in concrete mix designs is the improved resistance to chloride permeability while some improvements is flexural strength were realized and tensile strength was essentially unchanged. Potentially significant benefits may also be offered by using UFA as a process addition in the manufacture of cement clinker.},
doi = {10.2172/886683},
url = {https://www.osti.gov/biblio/886683}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2006},
month = {Thu Jun 01 00:00:00 EDT 2006}
}