Appeal No. 96-3499 Page 6
Application 08/271,569
In our view, however, the present record does not afford
an adequate basis for concluding that an artisan with ordinary
skill in the art would have been taught to modify the high
temperature, high pressure extraction process of Wiewiorowski
to use a temperature of about 90°C at atmospheric pressure to
leach and convert, with aqueous sodium hydroxide, at least 77
percent of the tungsten in a tungsten containing spent
catalyst to sodium tungstate in accordance with the process of
appealed claim 1.
We note that patentee does not appear to ascribe any such
significance to the Table 1 results regarding the extraction
of molybdenum, vanadium and sulfur. Nor has the examiner
furnished any additional evidence regarding the recovery of
tungstate from tungsten containing spent catalysts using
aqueous sodium hydroxide leaching at about 90°C at atmospheric
pressure conditions.
Rejections based on § 103 must rest on a factual basis
without the use of impermissible hindsight gleaned from
appellants' disclosure. The examiner may not, because of
doubt that the invention is patentable, resort to speculation,
unfounded assumption or hindsight reconstruction to supply
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007