Method of treating heavy metal and/or organic compound

Abstract

The present invention provides a method of purifying polluted soil and/or burned ash containing heavy metals and/or organic compounds with a higher throughput than a conventional method. In this method, polluted soil and/or burned ash is dried by, for example, a rotary dryer so that the moisture content is 5% by mass or less, preferably 3% by mass or less, and then large lumps having a particle diameter of 10 mm or more are removed by a vibrating screen. Only an undersize portion is formed into a briquette having a volume of about 6 cm 3 by a press molding machine. The briquette is charged in a rotary hearth furnace together with the large lumps, and heated in the furnace to remove or detoxify the heavy metals and organic compounds by evaporation with high efficiency.

What is claimed is:  
     
         1 . A method of treating a heavy metal and/or organic compound comprising a heating step of heating a material containing a heavy metal and/or organic compound, in a radiant rapid heating furnace to purify the material.  
     
     
         2 . A method of treating a heavy metal and/or organic compound comprising an agglomeration step of agglomerating at least a portion of a material containing a heavy metal and/or organic compound, to form agglomerates, and a heating step of heating the agglomerates and the unagglomerated residue of the material in a radiant rapid heating furnace to purify the material.  
     
     
         3 . A method of treating a heavy metal and/or organic compound according to  claim 2 , further comprising a screening step of screening the material to separate the material into an oversize portion and an undersize portion before the agglomeration step, the undersize portion being supplied to the agglomeration step, and the oversize portion being supplied to the heating step without the agglomeration step.  
     
     
         4 . A method of treating a heavy metal and/or organic compound comprising a mixing step of mixing a carbonaceous reducing agent and a metal oxide-containing material with a material containing a heavy metal and/or organic compound, and a heating step of heating the resultant mixture in a heating furnace to purify the material.  
     
     
         5 . A method of treating a heavy metal and/or organic compound according to  claim 2 , wherein the material is heated at an ambient temperature of 700° C. or more at least in the second half of the heating step.  
     
     
         6 . A method of treating a heavy metal and/or organic compound according to  claim 5 , wherein the material is heated at an ambient temperature of 700° C. or less in the first half of the heating step.  
     
     
         7 . A method of treating a heavy metal and/or organic compound according to  claim 2 , wherein the radiant rapid heating furnace is a rotary hearth furnace.