Appeal 2006-1516
Application 10/025,002
heat - 500°C to °1000C - that the petroleum coke will be exposed to prior to
reaching the kiln 46 will cause any sulfur in the petroleum coke to vaporize
and not be present in the kiln to increase phosphorus extraction efficiency”
(principal Br. 4, second para.). The Astley Declaration is offered to support
the argument that sulfur will vaporize in the Lapple process before the coke
reaches the kiln. However, the Examiner has effectively refuted Appellants’
argument.
First, the Examiner correctly points out that Lapple expressly teaches
that adding carbon by means of a fluid bed coater at elevated temperatures is
only a preferred way of adding the carbon. The reference explains that
pelletizing coal or coke with water is not desirable because the
defluorinated particles do not possess good binding characteristics but that
“if pelletizing is desired, an extraneous binding material other than water
must be used to form acceptable pellets, which necessarily complicates the
pelletizing operation” (col. 4, ll. 40-42). Consequently, if, as argued by
Appellants, one of ordinary skill in the art would have understood that
pretreating the coke at elevated temperatures would remove the sulfur, it
would have been a matter of obviousness for one of ordinary skill in the art
to perform a cost/benefit analysis in weighing the advantage of using sulfur
to enhance the extraction of phosphorus against the disadvantage of
complicating the pelletizing operation. Also, the Examiner properly points
out that Appellants themselves preheat pellets of silica, a carbon source
containing sulfur, and phosphate ore at 500°C without vaporizing and
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