ASX-listed mining exploration company AVZ Minerals has reported positive flotation test results of tin and tantalum recoveries at its Manono lithium and tin project in the Democratic Republic of Congo (DRC), with a total tin recovery of 63% with a grade of 64.1%.
AVZ has concentrated its efforts to date on defining a large hard-rock lithium resource at Manono, the area historically known to hold significant alluvial potential.
The explorer also reports tin and tantalum being well liberated and easily recoverable from the -0.5 mm high-pressure grinding rolls undersize material.
Initial preliminary test work was completed on six composite samples from the Manono alluvial fields adjacent to the known major pegmatites, in an effort to determine mineral and metal contents and understand initial potential economic viability to enable additional planning of exploration and assessment work.
The six samples, totalling about 50 kg, were submitted to Nagrom Laboratories of Perth, Western Australia, for assessment and analytical determination.
All samples were blended, coned and quartered from each of the six composites to produce a 1 kg sample for test analysis, as well as complete semi-quantitative X-ray diffraction, microscopy and full inductively coupled plasma analysis.
The explorer points out that the results show that the alluvial concentrate produced at the Manono site is rich in tin in the form of cassiterite and other potentially economic minerals. Tin grades of the six samples ranged from 29.5% to 71.5% tin oxide with an average grade of some 53.4% tin oxide.
Given the initial positive nature of the results and possible economic benefit to AVZ, further testwork has been organised and will include separating out the tin from other minerals. It is expected on the back of these results that a work programme will be implemented to assess the nature of all alluvial fields within Manono with the view to possibly placing them into production at some stage in the future.
AVZ MD Nigel Ferguson says the tin grades are, however, above 60% in both size ranges and are highly saleable products, which could potentially contribute to reducing overall operating costs and to supply a significant and growing demand from the electronics market.
“AVZ is currently in discussion with several potential offtake partners in this field.”
He adds that, in addition to the hard-rock tin and tantalum at Roche Dure, AVZ is now investigating recovery of the alluvial tin and tantalum present in significant quantities across the concession.
“As part of our social development programme, and in line with transparency in the supply of these minerals from Manono, we have commenced analysis of these alluvial heavy minerals to determine if the metal values warrant further investigation,” says Ferguson.
A 50 kg composite sample collected from across the site confirms tin values ranging from 29.5% to 71.5% cassiterite. He points out that this confirms historical reports by independent geological consultants, Bear Dolhbere, of a significant alluvial tin field at Manono.
“It appears, at least initially, that this material may also be economically recovered by working together with the community to maximise returns for both the company and all stakeholders.”