Patent References 2140850 2750290 3030222 3268443 3785840 InventorsAssigneeApplicationNo. 411366 filed on 10/31/1973US Classes:588/317, By hydrolysis (EPO/JPO)162/30.11, Treatment of kraft pulping chemicals162/36, Sulfur dioxide or sulfite containing spent liquor588/252, Solidification, vitrification, or cementation588/318, Detoxification by using acid or alkaline reagents (EPO/JPO)588/404Toxic combustion residues, e.g., toxic substances contained in fly ash from waste incineration (EPO/JPO)ExaminersPrimary: Hart, Charles N.Assistant: Hruskoci, Peter A. Attorney, Agent or FirmInternational ClassesA62D 3/00 (20060101)C04B 18/04 (20060101) C04B 18/00 (20060101) C04B 18/06 (20060101) C04B 18/02 (20060101) C02F 11/00 (20060101) B01D 53/50 (20060101) AbstractMethod for disposal of water soluble sodium sulfur oxide-containing wastes resulting from industrial processes producing fly and/or bottom ash from fossil fuel utilization and waste or excess sodium sulfur oxide compounds, particularly disposal of sodium sulfite and/or sodium sulfate resulting from wet or dry sodium alkali scrubbing of tail or flue gases to reduce SOx emissions therefrom as from smelters, power plants, paper plants, glass plants and industrial boiler operations. Process involves mixing sodium sulfur oxide wastes with an alumina and silica-containing fly ash and/or bottom ash, forming an agglomerate, such as a pellet or briquette, and sintering in the range of about (1000°-2300°F). The resultant sintered particle shows lower solubility than the current standard of calcium sulfate, being 10-2 to 10-4 as soluble as the starting sodium sulfur oxides, has increased density (as high as 2.3 g/l), and reduced volume as compared to the dry fly ash or sodium sulfur oxide wastes, and fixes heavy metals. Fly ash leaching and dusting problems are substantially overcome. Sodium sulfur oxides include sodium sulfite, sulfate, bisulfite, bisulfate, thiosulfite, persulfite (pyrosulfite), thiosulfate, persulfate (pyrosulfate), and mixtures thereof. Sintered particle may be disposed of by known landfill techniques, or used as an aggregate for mulch, road beds, concrete, asphalt or the like. | |