Apparatus and method for power generation and valuable element recovery from combustion by-products

Abstract

An apparatus for heat and power generation includes a combustor, operating at a temperature of 500-900° C., a leach tank downstream from the combustor, producing a valuable element solution from combustion by-products and a valuable element recovery apparatus configured to recover the valuable elements from the valuable element solution.

What is claimed: 
     
         1 . An apparatus for heat generation and enhanced recovery of valuable elements, comprising:
 a combustor operating at a temperature of 500-900° C.;   a leach tank downstream from the combustor, said leach tank (a) receiving combustion by-product from the combustor, (b) extracting the valuable elements from the combustion by-product and (c) producing a valuable element solution; and   a valuable element recovery apparatus configured to recover the valuable elements from the valuable element solution.   
     
     
         2 . The apparatus of  claim 1 , wherein said valuable element recovery apparatus includes:
 at least one of a thickener and a filter press downstream from the leach tank and adapted for removing residual solids from the valuable element solution and thereby generating a pregnant leach solution.   
     
     
         3 . The apparatus of  claim 2 , wherein the valuable element recovery apparatus further includes:
 a solvent extraction and precipitation apparatus downstream from the at least one of the thickener and the filter press and adapted to concentrate valuable elements in the pregnant leach solution and then selectively precipitate the concentrated valuable elements; and   a roaster, downstream of the solvent extraction and precipitation apparatus, adapted to produce a valuable element oxide mix.   
     
     
         4 . The apparatus of  claim 1 , wherein said combustor is a fluidized bed combustor. 
     
     
         5 . The apparatus of  claim 4 , wherein heat generated by the fluidized bed combustor is delivered to a steam generator and used to turn a turbine and generate electric power. 
     
     
         6 . The apparatus of  claim 5 , wherein said combustor is operated in an absence of alkaline additives used to capture sulfur. 
     
     
         7 . The apparatus of  claim 6 , wherein said combustor is operated at temperatures between 500-750° C. 
     
     
         8 . The apparatus of  claim 1 , further including a sulfuric acid plant adapted for producing sulfuric acid from exhaust gases of the fluidized bed combustor and delivering said sulfuric acid to said leach tank for use in extracting the valuable elements from the combustion by-product. 
     
     
         9 . A method for power generation and valuable element recovery from coal-based materials, comprising:
 combusting the coal-based materials to generate heat at a temperature of 500-900° C.;   using the heat to produce steam and generate electric power;   leaching the valuable elements from combustion by-products of the coal-based materials into a valuable element solution; and   recovering the valuable elements from the valuable element solution.   
     
     
         10 . The method of  claim 9 , wherein the recovering includes:
 concentrating the valuable elements into a pregnant leach solution;   precipitating the valuable elements from the pregnant leach solution; and   roasting the valuable element to produce a pure valuable element oxide mixture.   
     
     
         11 . The method of  claim 10 , including combusting the coal-based materials in an absence of alkaline additives used to capture sulfur. 
     
     
         12 . The method of  claim 11 , including producing sulfuric acid from exhaust gases generated during the combusting of the coal-based material. 
     
     
         13 . The method of  claim 12 , including using the sulfuric acid for the leaching of the valuable elements. 
     
     
         14 . The method of  claim 13 , including:
 using at least one of a thickener and a filter press to remove residual solids from the valuable element solution and produce the pregnant leach solution;   using solvent extraction in the concentrating of the valuable elements in the pregnant leach solution; and   using staged precipitation, selective precipitation or staged and selective precipitation in the precipitating of the valuable elements.   
     
     
         15 . The method of  claim 9 , including completing the combusting of the coal-based materials at a temperature of 550-850° C. 
     
     
         16 . The method of  claim 9 , including completing the combusting of the coal-based materials at a temperature of 550-800° C. 
     
     
         17 . The method of  claim 9 , including completing the combusting of the coal-based materials at a temperature of 600-750° C. 
     
     
         18 . The method of  claim 10 , including completing the combusting of the coal-based materials at a temperature of 550-800° C. 
     
     
         19 . The method of  claim 10 , including completing the combusting of the coal-based materials at a temperature of 600-750° C.