Abstract

Process for disposal of fossil fuel 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 Na2 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 FGD process. The resulting co-disposal process simultaneously renders the highly soluble Na2 SOx (102 g/L) and ash impermeable, and suitable for geomorphologically stable landfill disposal by known techniques to heights in excess of 200'.

Other References

• Toxic and Hazardous Waste Disposal, vol. 1, Processes for Stabilization/Solidification, edited by Robert B. Pojasek, Ann Arbor Science Publishers Inc., 1979, chapter 18, pp. 363-399