Ex parte RIJKEBOER et al. - Page 3




          Appeal No. 94-2858                                                          
          Application 07/873,715                                                      



               The references of record relied upon by the examiner are:              

          McDaniel                 4,324,769      Apr. 13, 1982                       
          Yamada et al. (Yamada)   4,426,363      Jan. 17, 1984                       
               The appealed claims stand finally rejected under 35 USC                
          § 103 over McDaniel in view of Yamada.                                      
               We reverse.                                                            
               The subject matter on appeal is directed to a process for              
          the production of aluminum hydroxide by digesting bauxite with              
          alkali solution and precipitating aluminum hydroxide from the               
          digestion solution.  As evident from step (h) of claim 53, the              
          source of the alkali solution used to digest bauxite is a spent             
          liquor recycle stream.  Such a step is conventional in the well             
          known prior art Bayer process wherein spent liquor, obtained                
          after precipitating aluminum hydroxide from the digestion                   
          solution in a later stage in the Bayer process, is used as the              
          aqueous alkali solution for digestion.  See the specification at            
          page 1, lines 13 through 16.                                                
               As appellants’ point out, the principal object of the                  
          claimed invention is to provide a method for the production of              
          aluminum hydroxide from bauxite, which in its essential form                
          includes two bauxite digestion stages, with intermediate                    


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