Birimian (ASX: BGS) has reported further thick and high-grade lithium assays from ongoing drilling at its Goulamina project in west Mali.
Resource drilling at the Sangar I and Sangar II deposits unearthed a massive 75m intersection grading 1.89% lithium, with other wide intersections including 59m grading 1.79% lithium and 27m grading 2.07% lithium.
Mineralisation at Sangar I and Sangar II remains open to the north and south and at depth.
According to Birimian, although drilling is still underway, the resource definition component covering the Main, West, and Sangar I and Sangar II deposits has been completed.
“The completion of the company’s intensive 14,000m reverse circulation and 19,000m auger drilling program during the five months to February 2018 has produced further outstanding results for the Goulamina project,” Birimian chief executive officer Greg Walker said.
“We set out to ensure that the project would not be resource constrained in our preferred development scenario and we will achieve this objective,” Mr Walker added.
A resource upgrade that incorporates the drilling data is pencilled in for the end of April.
Additional work on the project includes updating the open pit design that was published in last year’s pre-feasibility study.
The initial pit design comprised the West and Main zones, but the resource drilling campaign has discovered extensions to mineralisation at both these zones as well as Sangar I and Sangar I.
Birimian plans to redesign and enlarge the pit to accommodate the extra resources.
To progress the pit redesign, Birimian has consulted with an independent geological expert regarding undertaking a diamond core drilling program for geotechnical assessment, which is necessary to complete the pit designs and calculate a maiden ore reserve.
The revised pre-feasibility study has been pushed out to the June quarter for anticipated completion to ensure it includes metallurgical test work data and the additional resource tonnages.
Metallurgical data on 75 samples from the project has confirmed spodumene as the primary lithium mineral, with minor amounts of petalite found in two samples.
Birimian claims the fact petalite was only found in two samples was a good indication the mineralogy at Goulamina was amenable to lower cost processing methods.
Meanwhile, two diamond rigs are generating core samples for testing. The company has shipped 6t of drill core to Perth for analysis to-date.
Birimian anticipates the results from metallurgical test work will feed into its feasibility studies.
Further exploration at Sabali
The augur drilling program identified the Sabali anomaly about 2km south of Sangar II.
Birimian plans to drill the anomaly with reverse circulation holes once it has wound up resource drilling at the Yando and Danaya deposits.
Shares in Birimian fell more than 7% by early afternoon trade to A$0.52.