Australian exploration firm embarks on drilling campaign at Tanzania graphite project

AUSTRALIA-based exploration company Uranex started a drilling programme at its Nachu graphite tenement in south-east Tanzania late last month after successfully completing an electromagnetic (EM) survey.

The EM survey results of the 147 km2 of land surveyed indicates a 5.5 km2 of highly conductive zones on the tenement. These promising results indicate that there is a strong possibility of a significant graphite resource on the tenement, Uranex CEO Rod Chittenden tells Mining Weekly.

The EM survey areas were calculated based on an 888 Hz frequency, which is indicative of the conductivity at a depth greater than 35 m. The area covered by the EM survey accounts for 63% of the strike length of mineralisation indicated by the outcrop sampling.

The results from the interpretation of the other frequencies used in the EM survey show that these conductor zones are reasonably continuous from just below the surface to depths of more than 45 m.

The EM drilling programme will continue to cover the area between the northern and southern zones, as about 45 km of survey still has to be completed in the extended exploration programme.

As a result of the promising EM survey results, Uranex’s geology team started the drilling programme using a reverse-circulation drilling rig to primarily confirm whether the conductive zones are mineralised and the depth of mineralisation.

Guideline The drill chips from the drill programme will provide the geologists with a visual indication of the grade of the graphite, which the team will use as a guideline for further drilling.

Subsequent to the drilling programme, diamond drilling of the most prospective areas will be undertaken to provide samples for analysis and further metallurgical testwork, says Chittenden.

Basic exploration on the Nachu tenement, which is situated west of the coastal city of Lindi and about 200 km from the port city of Mtwara, in south-east Tanzania, started in February when Uranex geologists visited the site and uncovered further graphite outcrops, in addition to the outcrop uncovered in December 2012.

This initial exploration programme entailed surface sampling, surface mapping and sample analysis and was followed by a programme of trenching in areas of graphitic mineralisation in outcrops.

During the trenching, which started in June, five trenches were completed for a total length of 3.674 m and 2.049 m of this trenching exposed graphitic mineralisation, notes Chittenden.