In an update on the initial 55 holes of a 180-hole drill programme at its large-scale Letlhakane uranium project in Botswana, ASX-listed Lotus Resources has reported that completed drill holes have intersected mineralisation confirming continuity and grade.

The reverse circulation (RC) drilling is being carried out by Rotsdrill Exploration, a Botswana-registered drilling contractor, with the downhole radiometric logging being carried out by Lotus’ own geological team.

Equivalent U₃O₈  (eU₃O₈) intercepts reported have been calculated from down-hole gamma survey data using a 100 ppm cut-off, a minimum width of 50 cm and a maximum 25 cm internal dilution.

The company notes that physical samples will also be collected during the programme and submitted to an accredited laboratory along with the prerequisite certified reference materials, duplicates and blanks to meet its internal quality assurance and quality control requirements and those of the Joint Ore Reserve Committee Code.

All but two drill holes completed to date have intersected uranium mineralisation and confirm the continuity and grade of the deposit.

Uranium intercepts for the first 55 drill holes have been calculated from down-hole gamma survey data.

Lotus says the results of this drill programme will be used to prepare an updated mineral resource estimate (MRE), including increased measured and indicated (M&I) resources.

“Letlhakane’s pit-constrained MRE for 118-million pounds, grading 345 ppm U₃O₈, confirmed that Letlhakane is a large and attractive standalone – potentially company-making – project,” says Lotus MD Keith Bowes.

He notes that the infill programme has confirmed the company’s initial interpretation that higher-grade pods sit within the current resource shell, with the highest grade intercept reported so far at 2  844 ppm eU₃O₈ – eight times higher than Lotus’ average resource grade.

He adds that the shallow depth of the deposit, with the maximum depth drilled for this part of the programme of only 73 m, and the majority of mineralisation occurring at depths of between 25 m and 50 m.

Lotus’ drill programme primarily aims to upgrade inferred resources currently contained within the MRE (71%) to M&I status. The bulk of the inferred resources lie within the Gorgon West and Serule West areas and represent the main targets for the current drill programme.

Lotus has planned about 170 drill holes to bring the drill spacing down from 400 m centres to 200 m centres at Gorgon West and from 200 m centres to 100 m centres at Serule West.

The company says locations of the drill holes have been guided by the pit optimisation testwork conducted by SnowdenOptiro earlier this year, which was used to define the pit-constrained resource.

Lotus has also planned ten drill holes to test isolated high-grade intercepts from historical drilling west of the existing resource base.

“This infill drilling will improve confidence in Letlhakane’s MRE classification and is an important part of the development process. These initial results confirm the continuity of the resource, while showing grades well in excess of the average of the resource grade in several holes, providing confidence that this drilling will be successful in upgrading the classification of the Letlhakane resource,” says Bowes.

He notes that the company has decided to drill test an exploration target outside the current MRE envelope in this campaign. Historical results in this area include two holes with intercepts greater than 750 ppm eU₃O₈.

Bowes says this part of the programme will seek to increase Letlhakane’s overall resource size, adding that on the completion of this drill programme, an updated MRE will be prepared that will be used as part of the planned study work next year.

Letlhakane’s recently revised MRE, constrained by pit shells based on reasonable prospects of eventual economic extraction, is 155.3-million tonnes at 345 ppm U₃O₈ for 118.2-million pounds U₃O₈, of which 34.4-million pounds are indicated resources.

Lotus notes that infill drilling is aimed at the classification of Letlhakane’s resources. The programme will comprise up to 15 000 m reverse circulation and 1 500 m diamond drilling for about 170 drill holes.

Closer drill hole spacing will enable conversion of inferred resources to M&I categories while improved definition of higher-grade zones within the resources will help target mining activities.

On May 24, two RC rigs were mobilised to Letlhakane, with a diamond drill rig to follow at the beginning of July.

The diamond drilling will be spread throughout the infill areas to help better identify the mineral horizons and to collect samples that will be used in the planned mineral characterisation and metallurgical test work programmes.

Drilling started in the south of the deposit at Serule West. Completion of the infill drill program is expected to take about three months.

The company says large-diameter diamond core drilling will provide samples for metallurgical studies.