Waste treatment furnace and method

Abstract

This invention relates to a waste treatment furnace and method comprising: Generating a molten metal bed, which moves in a forward direction, such as to define a closed circuit in a cyclical and continuous manner, the surface of said bed comprising at least one essentially-slag-free segment. Loading waste onto the aforementioned essentially-slag-free segment, the waste being dragged by the molten metal bed such that it floats in the mentioned forward direction. Retaining the waste on the surface of the molten metal bed as it moves in the mentioned forward direction. Treating the waste under the effect of the constant and continuous heat exchange generated by the movement of the molten metal bed beneath the waste retained thereon.

1 - 36 . (canceled) 
   
   
       37 . A waste treatment method, comprising:
 generating a molten metal bed, which moves in a forward direction, such as to define a closed circuit in a cyclical and continuous manner, the surface of said bed comprising at least one essentially-slag-free segment;   loading waste comprising a metal fraction that is soluble in the molten metal bed at the temperature of the molten metal bed, onto the aforementioned essentially-slag-free segment, the waste being dragged by the molten metal bed such that it floats in the mentioned forward direction;   retaining the waste on the surface of the molten metal bed as it moves in the forward direction;   treating the waste under the effect of constant and continuous heat exchange generated by movement of the molten metal bed beneath the waste retained thereon, the waste treatment being carried out substantially on the molten metal surface, without need to immerse the waste in the molten metal, such that the treatment of the waste begins after the loading of the waste and is completed when retained, the treatment comprising the incorporation of the metal fraction of the waste that is soluble at the temperature of the molten metal bed to the molten metal bed;   further heating near the retaining of the waste in order to accelerate treatment thereof; and   extracting the slag carried out in a zone of said circuit located after the zone of retaining and treating the waste and before the loading zone of the waste corresponding to the next cycle.   
   
   
       38 . A waste treatment method according to  claim 37 , wherein the waste comprises a volatilizable fraction. 
   
   
       39 . A waste treatment method according to  claim 37 , wherein the volatilizable fraction comprises a metal part. 
   
   
       40 . A waste treatment method according to  claim 37 , comprising a volatilizable fraction treatment and extraction phase. 
   
   
       41 . A waste treatment method according to  claim 37 , wherein the waste comprises a fraction that is non-soluble at the temperature of the molten metal bed and non-volatilizable. 
   
   
       42 . A waste treatment method according to  claim 41 , wherein the waste treatment causes incorporation of the fraction that is non-soluble at the temperature of the molten metal bed and non-volatilizable to the molten metal bed in the form of slag. 
   
   
       43 . A waste treatment method according to  claim 37 , further comprising loading of the waste in a continuous manner. 
   
   
       44 . A waste treatment method according to  claim 37 , comprising heating the molten metal bed in order to obtain a homogeneous temperature in the essentially-slag-free segment. 
   
   
       45 . A waste treatment method according to  claim 44 , wherein the heating of the molten metal bed occurs by means of plasma techniques. 
   
   
       46 . A waste treatment method according to  claim 44 , wherein the heating of the molten metal bed occurs by means of an electric arc. 
   
   
       47 . A waste treatment method according to  claim 37 , comprising a discretional tapping phase for tapping part of the molten metal bed. 
   
   
       48 . A waste treatment method according to  claim 37 , wherein the molten metal bed has a higher specific surface area in the heating and treatment areas relative to the total molten metal bed mass when loading the waste and when retaining and treating the waste. 
   
   
       49 . A waste treatment method according to  claim 37 , wherein the molten metal bed is formed by ferrous metals. 
   
   
       50 . A waste treatment method according to  claim 37 , wherein the molten metal bed is formed by non-ferrous metals. 
   
   
       51 . A waste treatment method according to  claim 37 , wherein the waste is selected from the group consisting of: steelmaking dust, aluminum slag or chips, precious metals, waste with radiological activity, rolling sludge and scale, electronic scrap, ashes, and asbestos. 
   
   
       52 . A waste treatment method according to  claim 37 , wherein the waste is in the form of pellets or briquettes. 
   
   
       53 . A waste treatment furnace comprising:
 a tank of molten metal, wherein the tank of molten metal is carried in a channel forming a closed circuit in which the molten metal moves in a continuous and cyclical manner due to the action of a driving means;   at least one loading area for loading waste;   at least one treatment area comprising a retaining means located above the molten metal surface so that the circulation of molten metal is allowed, wherein the retaining means is positioned such that waste is dragged by the molten metal so that it floats until it reaches the retaining means; and   at least one slag extraction area located after the treatment area and before the loading area.   
   
   
       54 . A waste treatment furnace according to  claim 53 , wherein the tank of molten metal has less depth in the treatment and heating areas compared to its horizontal section in the loading area and in the treatment area. 
   
   
       55 . A waste treatment furnace according to  claim 53 , wherein the treatment area is defined between the waste loading area and the slag extraction area. 
   
   
       56 . A waste treatment furnace according to  claim 53 , further comprising at least one heating area comprising heating means to provide a homogeneous temperature in the loading area. 
   
   
       57 . A waste treatment furnace according to  claim 56 , wherein the heating means comprises an electric arc. 
   
   
       58 . A waste treatment furnace according to  claim 56 , wherein the heating means comprises a plasma torch. 
   
   
       59 . A waste treatment furnace according to  claim 53 , further comprising an additional heating area arranged near the retaining means to accelerate the waste treatment. 
   
   
       60 . A waste treatment furnace according to  claim 53 , further comprising at least one extraction and treatment area for extracting and treating a volatilizable fraction of the waste. 
   
   
       61 . A waste treatment furnace according to  claim 60 , wherein the extraction and treatment area extends to the mentioned at least one treatment area and/or at least one loading area. 
   
   
       62 . A waste treatment furnace according to  claim 56 , wherein the at least one waste loading area is located before the position of the heating means to introduce waste having a high smelting temperature and generating few gases. 
   
   
       63 . A waste treatment furnace according to  claim 56 , wherein the at least one waste loading area is located in coincidence with the heating means for introducing waste with a fine granulometry and which generates few gases or requires an inert atmosphere. 
   
   
       64 . A waste treatment furnace according to  claim 56 , wherein the at least one loading area is located after the position of the heating means to introduce waste with high fume generation. 
   
   
       65 . A waste treatment furnace according to  claim 53 , further comprising discretional tapping means for tapping part of the molten metal. 
   
   
       66 . A waste treatment furnace according to  claim 53 , wherein the molten metal is formed by ferrous metals. 
   
   
       67 . A waste treatment furnace according to  claim 53 , wherein the molten metal is formed by non-ferrous metals. 
   
   
       68 . A waste treatment furnace according to  claim 53 , wherein the waste is selected from the group consisting of: steelmaking dust, aluminum slag or chips, precious metals, waste with radiological activity, rolling sludge and scale, electronic scrap, ashes, asbestos. 
   
   
       69 . A waste treatment furnace according to  claim 53 , wherein the waste is in the form of pellets or briquettes.