Lindian Resources' maiden auger drilling program at its Gaoual bauxite project in Guinea has confirmed that the company is sitting on a very high-grade conglomerate-hosted bauxite deposit, with drill holes encountering exceptional grades of over 60% aluminium oxide right across the Bouba Plateau. The thickness of the mineralisation varies and in some areas is over 15m according to Lindian.
The drilling was spaced 300 metres apart, which the company says is enough to potentially put together a resource that will comply with JORC 2012 and also have a high degree of confidence.
Lindian has been getting real-time hints of its drilling success at Bouba with portable XRF sampling equipment providing some preliminary results prior to the final laboratory assays.
Some of the best XRF results include 12 metres grading 61.3% aluminium oxide, 5.3% silica and 4.9% iron oxide and also 10 metres grading 62.7% aluminium oxide, 4.5% silica and 8.1% iron oxide from another hole.
Lindian Managing Director, Shannon Green, said: “To have the initial drilling program confirm our belief that the Bouba Plateaux is very high-grade Conglomerate Bauxite is truly a watershed moment for the Company and to also have the very large Mamaya Plateaux show that it consistently contains in situ bauxite giving our project area significant scale.”
Lindian previously said the Bouba Plateau covers an area about five kilometres square and the ASX-listed company this week revealed that its maiden drilling hit a conglomerate-hosted bauxite that is geologically quite consistent. This is important, as it increases the chances of the ore behaving well metallurgically if it is eventually processed through a mill.
According to ALS Laboratories, quantifying the impurities in bauxite deposits is important because of its detrimental effects when it comes to refining the alumina.
Interestingly, the Bouba Plateau conglomerate shows no sign of increasing iron levels towards its base like most typical in situ bauxite deposits do.
Iron is recognised as an “impurity” in bauxites that may reduce the final aluminium content. It may even need to be removed before the aluminium is recovered during processing so lowish grades of iron are welcomed.
Lindian also said that Bouba has very slightly elevated levels of silica thought to be related to air-borne silica-sand grains, rather than the nuisance “reactive” silica that is sometimes present in clay minerals.
ALS also said that a higher reactive silica content can lead to higher caustic soda consumption during the refining process and can also result in a higher concentration of alumina being lost to tailings.
Lindian has also confirmed that its other target, Mamaya, is a large, in situ bauxite plateau with drilling intersecting widths of around 15 metres.
Mamaya covers about 11 kilometres square, however, mechanical issues with the drill rig have hindered the progress of its maiden program, however to date, six square kilometres of in situ bauxite have been confirmed at Mamaya.
The company has not yet established the depth of the Mamaya plateau because the auger drilling rig has not yet reached the base.
Lindian has experienced some issues with its XRF sampling equipment and has not been able to take any preliminary aluminium oxide readings from Mamaya.
Meanwhile, Lindian’s Geologists are mapping outcropping areas of bauxite and the drill rig is expected to complete the 600 to 300 metre spaced drill program across Mamaya.
The Perth based company is planning on follow up drilling that will include metallurgical and physical property test work set to kick off as soon as the maiden program results are all in.
Lindian’s flagship Gaoual project is located around 165 kilometres northeast of the Kamsar port.
The company can acquire an initial 51% interest in Gaoual from KB Bauxite Guinea SARLU and its sole shareholder, Guinea Bauxite, by pumping USD$1 million into the ground over the next few years.
It also has the right to move to a 75% holding via a longer-term deal after certain project milestones have been achieved and further monies spent on the project.
With further news and numbers to come, Lindian should have its hand full as it wrestles with its highly sought after conglomerate deposit.
Is your ASX listed company doing something interesting ? Contact : matt.birney@businessnews.com.au
