AVZ’s Manono delivers strong lithium recoveries
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Special Report: AVZ continues to notch up the successes in the DRC, with phase two of its initial metallurgical test program demonstrating strong lithium recoveries.
Phase two flotation tests of material from the Manono lithium and tin project in the Democratic Republic of Congo returned consistent recoveries averaging 69 per cent after adjusting for losses to slimes, magnetic separation and flotation tailing.
Significantly, AVZ Minerals (ASX:AVZ) says the resulting spodumene concentrate had grades ranging from 6.1 per cent lithium oxide (Li2O) to 6.4 per cent Li2O, above its target of 6 per cent Li2O.
The company added that while iron levels were within the spodumene concentrate specification, it had managed a marked decrease in iron content by increasing the intensity of the magnetic field during magnetic separation.
Previous bulk processing of ore from the Roche Dure deposit had recovered more than 60 per cent lithia with a concentrate grade of 6.1 per cent Li2O.
AVZ also carried out initial metallurgical testing of a 100kg bulk diamond core sample from the Carriere de l’Este deposit within the Manono project.
Using the same techniques as the phase one Roche Dure metallurgical study, this produced a spodumene concentrate with 6.2 per cent and 6.3 per cent Li2O at the 5.56mm and 3.35mm crush size respectively.
Managing director Nigel Ferguson says the initial results of the flotation test program demonstrated extremely positive additional lithia recoveries.
“This demonstrates, at an early stage, there is significant upside for the potential maximisation of spodumene recovery by the flotation treatment of the undersize material from the planned Roche Dure crushing circuit,” he explained.
Ferguson added that the results from initial testing of ore from the Carriere de l’Este deposit suggested that its material could be used as blending feedstock at the Roche Dure process plant to decrease feed tonnes and increase the lithium content and value of the final product.
“It also opens up the possibility of this material being used as a feedstock to a downstream processing plant such as a lithium sulphate plant with less tonnages of material being required to produce a value-added product, a possibility that we are currently, vigorously investigating,” Ferguson said.
AVZ said preliminary flotation test work is now complete though additional work is expected after completion of definitive feasibility study (DFS) activities.
Future work will be required to generate definitive design data to de-risk [ the complex process.