Chloride leaching from air pollution control residues solidified using ground granulated blast furnace slag.
Ground granulated blast furnace slag (ggbs) has been used to solidify air pollution control (APC) residues obtained from a major UK energy-from-waste plant. Samples were prepared with ggbs additions between 10 and 50 wt% of total dry mass and water/solids ratios between 0.35 and 0.80. Consistence, setting time, compressive strength and leaching characteristics have been investigated. Results indicated that the highly alkaline nature of APC residues due to the presence of free lime can be used to activate ggbs hydration reactions. Increasing ggbs additions and reducing the water content resulted in increased compressive strengths, with 50 wt% ggbs samples having average 28 d strengths of 20.6 MPa. Leaching tests indicate low physical encapsulation and minimal chemical fixation of chloride in ggbs solidified APC residues. The results suggest that more than 50 wt% ggbs additions would be required to treat APC residues to meet the current waste acceptance criteria limits for chloride.
Lampris
Christos
C
Centre for Environmental Control and Waste Management, Department of Civil and Environmental Engineering, Skempton Building, Imperial College, London SW7 2AZ, UK.
Stegemann
Julia A
JA
Cheeseman
Christopher R
CR
D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control; D002712:Chlorides / Q000032:analysis / Q000737:chemistry*; D017745:Incineration / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis
D000393:Air Pollutants; D002712:Chlorides; D007220:Industrial Waste