The Catalao project is located in the
state of Goiás, approximately 280 kilometres south of
Brazil’s capital city, Brasilia. The Catalão 1
kimberlite cluster covers a surface area of 0.75
hectares and is comprised of three pipe-like deposits
named Catalão 1A, 1B and 1C. These pipe-like deposits
are approximately 0.30, 0.25 and 0.20 hectares
respectively.
The kimberlite cluster was discovered
in the 1970s by a subsidiary of De Beers Consolidated
Mines Limited. Rio Tinto acquired an exploration license
covering an area surrounding the kimberlite in 1998 and
completed a detailed exploration program over the
following two years which included airborne and ground
geophysical surveys, core drilling and mini-bulk
sampling. Rio Tinto’s mini-bulk sampling program focused
on a surface exposure of the Catalão 1A pipe, where
three mini-bulk samples with a total weight of
approximately 3.6 (dry) tonnes resulted in the recovery of 52
diamonds with a total weight of 0.85 carats.
The 5,100 (dry) kilograms of
drillcore sample from Catalão 1A was processed using the
caustic fusion process at Rio Tinto’s facility in
Brazil. The 3.6 tonne mini-bulk sample from Catalão 1A
was initially treated at Rio Tinto’s facility in Brazil
by scrubbing and screening to liberate the diamonds and
reduce the volume of the sample. Following attrition,
the >0.500 mm fraction was passed through a bromoform
solution to produce a heavy mineral concentrate
containing diamonds, which were picked under the
microscope.
Rio Tinto also completed a drilling
program comprising 16 core holes totalling 1,050 metres
to define the limits of the Catalão 1A, 1B and 1C bodies
to a maximum depth of 201 metres. A total of 5.14 (dry) tonnes
of kimberlite was processed for total diamond recovery
by caustic fusion resulting in the recovery of 145
diamonds with a total weight of 0.51 carats.
Vaaldiam plans to pursue an
aggressive evaluation program which includes definition
drilling to further define the known kimberlites on the
Property and the completion of an additional bulk
sampling program recovering approximately 150 tonnes of
kimberlite from the Catalão diamond bearing kimberlites.
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