Abstract:
A process is disclosed for recovering raw materials, in particular heavy metals such as chromium, by separation from waste and residues, wherein a liquid or viscous starting mixture and/or a starting mixture composed of crushed or ground components is first prepared. The invention is characterized in that the raw materials are separated by a thermochemical treatment. The liquid, viscous and/or solid starting mixture is first mixed with additives, depending on its composition, then subjected to a thermal treatment in an oven. The atmosphere in the oven flows through the starting mixture and the suspended materials thus generated as flakes or dust are conveyed out of the oven through a filter installation with several stages in which they are separated from the waste gas. The first filter is designed as a hot filter, after which the waste gas is cooled and after flowing through at least a second filter, pre-heated and then burnt at a high temperature.
Abstract:
An apparatus for treating organic waste material characterized by high ash content is disclosed. The apparatus includes a slagging combustor for burning the organic waste material to produce a slag of molten inorganic ash and exhaust gases, a cooler for receiving the exhaust gases from the combustor and cooling the exhaust gases, a condenser for receiving cooled exhaust gases from the cooler and drying the cooled exhaust gases, an exhaust gas recirculation conduit for receiving a first portion of cooled and dried exhaust gases from the condenser, and a source of concentrated oxygen gas in fluid communication with the exhaust gas recirculation conduit for adding concentrated oxygen gas to the first portion of cooled and dried exhaust gases to create a gas mixture that is added to the combustor through the exhaust gas recirculation conduit, wherein the source of concentrated oxygen gas includes a valve responsive to an oxygen sensor in the exhaust gas recirculation conduit for regulating the flow of concentrated oxygen gas into the exhaust gas recirculation conduit.
Abstract:
In the conventional incineration of solid waste materials, flyash present in the combustion products gas stream catalyzes the formation of toxic dioxins from chlorinated organic materials. By providing a catalyst poison, such as carbon disulphide, in association with the flyash, typically by spraying onto the solid wastes prior to incineration, the catalytic effect is decreased, resulting in decreased dioxin formation.
Abstract:
A method of burning waste comprised essentially of plastic, especially PVC waste. The waste is burned in a revolving cylindrical furnace accompanied by the addition to the waste of at least one finely ground solid additive having at least one component with a melting temperature higher than the melting temperature of the plastic of the waste.
Abstract:
A process and system for treating organic waste materials without venting gaseous emissions to the atmosphere. A fluidized bed including lime particles is operated at a temperature of at least 500.degree. C. by blowing gas having 20%/70% oxygen upwardly through the bed particles at a rate sufficient to fluidize same. A toxic organic waste material is fed into the fluidized bed where the organic waste material reacts with the lime forming CaCO.sub.3. The off gases are filtered and cooled to condense water which is separated. A portion of the calcium carbonate formed during operation of the fluidized bed is replaced with lime particles. The off gases from the fluidized bed after drying are recirculated until the toxic organic waste material in the bed is destroyed.