Abstract

Process for disposal of a waste ash by addition thereto of sodium salts, preferably sodium sulfur oxide salt Na2 SOx where x is 3 and/or 4, in an amount ranging from 5-85 weight percent (dry basis) and adjusting the water percentage to within the range of 6-35%, preferably 15-28%. The coefficient of permeability of the ash and sodium salt is reduced from 102 cm/sec to the "impermeable" standard of 10-6 and below. The preferred mixes also call for a smectite clay additive present in the range of from 0.1% to 5%. A flocculant in amounts of 0.01% to 1% can be substituted for about 3-5% of the water content. A principal source of the Ma2 SOx is sodium FGD waste, preferably from the use of Nahcolite (a natural mineral form of sodium bicarbonate) as an SOx sorbent in the Nahcolite FGC process. The resulting co-disposal process simultaneously renders the highly soluble Na2 SOx (102 g/L) an ash impermeable, and suitable for geomorphologically stable landfill disposal by known techniques to heights in excess of 200'. Any waste ash may be used, for example, municipal or industrial incinerator ash, fly ash and/or bottom ash from industrial or power plants burning fossil fuels for steam or eneryg, or scrubber sludges. The scrubber sludge may be from sodium or calcium sorbent scrubbers and may contain fly ash and/or bottom ash. Waste ash sources may be mixed and disposed by the process.