Device and Method for the Thermal Treatment of Fluorine-Containing and Noble Metal-Containing Products

Abstract

The present invention relates to an ashing plant for enriching noble metals from fluorine-containing materials, comprising a thermal treatment chamber ( 1 ) having a refractory insulating lining on the inside of the chamber and an exhaust gas cleaning system, whereby the refractory insulating lining is resistant to hydrofluoric acid and the exhaust gas cleaning system comprises at least one thermal after-incineration chamber ( 2 ), at least one or more acid scrubber(s) ( 3, 4 ) and at least one alkaline scrubber ( 5 ).

1 . Ashing plant for enriching noble metals from fluorine-containing materials, comprising
 a thermal treatment chamber ( 1 ) having a refractory insulating lining on the inside of the thermal treatment chamber ( 1 ), and   an exhaust gas cleaning system,   whereby the insulating lining is resistant to hydrofluoric acid and   the exhaust gas cleaning system comprises at least one or more acid scrubber(s) ( 3 ,  4 ) and at least one alkaline scrubber ( 5 ).   
     
     
         2 . The ashing plant according to  claim 1 , wherein the exhaust gas cleaning system further comprises at least one or more thermal after-incineration chambers ( 2 ). 
     
     
         3 . The ashing plant according to  claim 2 , wherein the inside of the at least one thermal after-incineration chamber ( 2 ) is provided with a hydrofluoric acid-resistant refractory insulating lining. 
     
     
         4 . The ashing plant according to  claim 1  wherein the plant further comprising an exhaust gas conduit ( 6 ) for guiding the exhaust gases out of the thermal treatment chamber ( 1 ) and in that the inside of said exhaust gas conduit ( 6 ) is provided with a hydrofluoric acid-resistant refractory insulating lining. 
     
     
         5 . The ashing plant according to  claim 1  wherein the refractory insulating lining has an aluminium oxide (Al 2 O 3 ) content of 85% by weight or more. 
     
     
         6 . The ashing plant according to  claim 1  wherein the thermal treatment chamber ( 1 ), after-incineration chamber ( 2 ), and exhaust gas conduit ( 6 ) comprise different insulating lining(s). 
     
     
         7 . The ashing plant according to  claim 1  wherein thermal treatment chamber ( 1 ), after-incineration chamber ( 2 ) and/or exhaust gas conduit ( 6 ) further comprise an external lining. 
     
     
         8 . The ashing plant according to  claim 7 , wherein the external lining is a mineral fibre. 
     
     
         9 . The ashing plant according to  claim 1  wherein the exhaust gas cleaning system comprises at least one scrubber made of graphite ( 3 ) with a double-walled design. 
     
     
         10 . The ashing plant according to  claim 9 , wherein the double-walled scrubber ( 3 ) comprises a water cooling system. 
     
     
         11 . The ashing plant according to  claim 1  wherein the exhaust gas cleaning system comprises at least one single-walled scrubber ( 4 ) made of graphite. 
     
     
         12 . The ashing plant according  claim 1  wherein the exhaust gas cleaning system comprises a double-walled scrubber made of graphite ( 3 ) and a single-walled scrubber made of graphite ( 4 ). 
     
     
         13 . The ashing plant according to  claim 1  wherein the alkaline scrubber ( 5 ) comprises on its inside a coating made of a plastic material, in particular made of polypropylene. 
     
     
         14 . The ashing plant according to  claim 1  further comprising a control unit. 
     
     
         15 . Method for enriching noble metals from fluorine-containing materials, comprising
 a thermal treatment of the materials in a thermal treatment chamber ( 1 ) having a hydrofluoric acid-resistant refractory insulating lining, and   a cleaning of the exhaust gases generated during the thermal treatment, whereby the cleaning comprises the following steps in the following order:   a) if applicable, thermal after-incineration in an after-incineration chamber ( 2 ),   b) scrubbing of the exhaust gases with water and/or an acid, and   c) scrubbing of the exhaust gases with a base.   
     
     
         16 . The method according to  claim 15  wherein step b) comprises the following steps:
 b1) scrubbing and simultaneous cooling of the exhaust gases in a double-walled graphite scrubber ( 3 ) followed by 
 b2) scrubbing of the exhaust gases in a single-walled graphite scrubber ( 4 ). 
 
     
     
         17 . The method according to  claim 15 , wherein the salt-enriched scrubbing water obtained in step b) can be fed to a waste water treatment plant periodically or continuously as side stream. 
     
     
         18 . The method according to  claim 15  wherein the exhaust gases are washed in step c) with a base with a pH of at least 10 or more. 
     
     
         19 . The method according to  claim 15  wherein materials having a fluorine content of up to 5% by weight are used as materials to be subjected to the thermal treatment. 
     
     
         20 . The method according to  claim 15  wherein fluoro-organic materials, PTFE films, fuel cells, catalysts and/or pastes are used as materials to be subjected to the thermal treatment. 
     
     
         21 . The method according to  claim 15  wherein the method is implemented in an ashing plant comprising
 a thermal treatment chamber ( 1 ) having a refractory insulating lining on the inside of the thermal treatment chamber ( 1 ), and 
 an exhaust gas cleaning system, 
 whereby the insulating lining is resistant to hydrofluoric acid and 
 the exhaust gas cleaning system comprises at least one or more acid scrubber(s) ( 3 ,  4 ) and at least one alkaline scrubber ( 5 ). 
 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled)