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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