Abstract: The slag that is formed in garbage and waste incinerators is cleaned of coarse material and iron directly after the slag outlet (1) from the incinerator. Separation into two fractions takes place after coarse cleaning, in a fractionating unit (6). One of the fractions contains all the particles that are smaller than 2 mm. At the same time, the dust is separated by a suction system (14). Dust and particles smaller than 2 mm contain practically all the soluble harmful substances and have to be processed and stored observing special precautions, or dumped. The remaining, cleaned slag is dry, and can be used as construction material. The process and the apparatus avoid the use of a water bath, so that no energy is needed for drying.

Abstract: After quenching, the slag that is generated in garbage and waste incinerators is subjected to an additional washing process in a washer unit (2). During the wash process, harmful substances such as chlorides and heavy metals, for example, are washed out of the slag. The subsequent separation of the water from the slag is effected in a separator system (4) and in a drying system (7). The slag is dried to a maximum water content of 20% and the fine components with a grain size of less than 2 mm are removed from the slag either during or after the drying process. These fine components and the wash water sludge contain practically all the soluble harmful substances, and must be processed or dumped while observing special precautions. The remaining clean slag is practically free of soluble harmful substances and can be used as construction material.

Abstract: The slag occurring in the waste burning plant (1) is conducted from the slag exit (6) of the oven, directly into a separator (7) for coarse material and iron. There is no chilling in water. After the coarse cleaning, the slag is heated again by means of hot flue gases from the waste burning oven (1) in a preheating device (8), and then, with the feeding of additional heat, melted in a melting oven (10). Flyash is mixed with the stream of slag before the preheating device (8). The harmful substances vaporizing in the preheating and melting are condensed out of the exhaust gases and recovered. Parallel with the preheating device (8) is arranged a pyrolysis oven (9) which is also heated with a partial stream of hot flue gas from the exhaust channel (3). The pyrolysis gas is used as fuel for producing additional heat in the melting oven (10). All the remaining harmful substances not vaporized enter into harmless compounds in the molten slag or are bound, insoluble by water, in the resultant fused slag.