Abstract: An improved process is disclosed for conveying trona powder to be used in treating flue gas to remove impurities from the flue gas. The trona powder is pneumatically conveyed under controlled conditions wherein a. the temperature of the conveying air is maintained at less than 135 degrees F., preferably less than 130 degrees F., b. the relative humidity of the conveying air is maintained between about 15% and 50% and c.

Abstract: The present invention is directed to a process of treating fly ash and/or fly ash leachate to immobilize heavy metals contained in such fly ash and/or fly ash leachate, which process comprises treating such fly ash and/or fly ash leachate with a soluble ferrous compound under alkaline conditions. This process may be conducted in the absence of any pH modification, mixing (in the sense of a physical blending with a solid material), drying or heating steps, making it practical for treatment of alkaline fly ash (and other coal combustion by-products) which is currently stored in landfills or wet ash lagoons, particularly fly ash which has been recovered from flue gas streams treated with highly alkaline materials such as trona, bicarbonate or limestone and the like.