Abstract: Non-hazardous organic waste material is introduced into a slagging combustor where it is burned. The burning produces exhaust gases and a slag of molten, inorganic ash which is removed from the combustor. The exhaust gases are treated to cool and dry the gases and to remove a major portion of particulate matter contained therein. A portion of the treated exhaust gases is mixed with a source of concentrated oxygen in a proportion that results in mixed gases having an oxygen concentration of at least 30% by volume. The mixed gases are introduced into the combustor to support the burning of the waste material. Another portion of the treated exhaust gases is further treated to recover the carbon dioxide therefrom.
Abstract: Paper mill sludge or similar organic sludges with a high ash content are converted by burning the sludge in a cyclone furnace along with another source of fuel. The heat content of the sludge is recovered and the ash content of the sludge is converted to a glassy slag. A flux, such as limestone, may be added to the sludge before introduction into the cyclone furnace. The slag is useful as a construction material, an abrasive, for roofing products, or for other purposes.
Abstract: A method is shown for producing a lightweight aggregate by treating flyash and sewage sludge. The flyash and sewage sludge are mixed together and then agglomerated into pellets, with or without the use of a binder. The pellets may be coated and then are dried. The dried pellets are introduced into a rotary kiln in a direction that is co-current with the flow of fuel and air through the kiln. The pellets in the kiln will be indurated and will experience complete calcination as well as varying degrees of pyrolizing and sintering. The product of the kiln is a nodular material having a low density but with a hard and porous structure. The product of the kiln is feed to a cooler. The flyash sewage sludge mixture has a significant fuel value that is usable in the kiln. Furthermore, the fuel valve available in the kiln off-gases may be used for drying the materials.