Angola – Following an initial metallurgical assessment programme at Rift Valley Resources Longonjo rare earth prospect in Angola, beneficiation test work produced a concentrate containing 19.44% rare earth oxides (REO).

Highlights of the test work include:

  • Beneficiation test work produced a concentrate containing 19.44% REO.
  • Results to date represent a greater than 3 times upgrade of the head sample.
  • Mineralogical test work better defines the oxide material.
  • Leach recovery test work to commence soon on a beneficiated concentrate.

Beneficiation test work has commenced on an oxidised surface composite from the Longonjo rare earth elements (REE) target at independent metallurgical operations (IMO). The composite head sample contained 6.47% REO.

Mineralogical test work has confirmed REO’s are primarily hosted within Monazite and various other complex minerals which may include secondary Cerianite.

XRD has indicated that Bastnasite may be present in trace amounts although discrete bastnasite grains were not detected. Based on the highly oxidised nature of this composite it has been assumed that any bastnasite present would have been leached during the weathering process.

Initial beneficiation bench scale rougher kinetic flotation tests have resulted in a stage 1 rougher concentrate containing 19.44% REO which represents a >3 times upgrade.

Beneficiation testwork is continuing with the aim of improving both REO upgrades and recoveries.

Upon the completion of beneficiation test work hydrometallurgical characterisation test work will be conducted on a beneficiated REO concentrate. The overall aim of this test work program is provide data which will enable an indicative financial model to be completed as input into a broad project evaluation.

The work to this point suggested that the Longonjo material was most likely suited to physical upgrading via flotation. As such, the current testwork programme was devised to collect sufficient material for quantitative mineralogy (QEMSCAN) as well as leaching and flotation test work.

Project background

The Longonjo REE prospect is located within the Ozango project, approximately 600 km southeast of the Angolan capital Luanda and 50 km west of the regional city of Huambo. It is located proximal to good infrastructure including roads, towns and the recently recommissioned railway which links the area to the deep water Atlantic port of Lobito.

The Ozango Project covers a large area of 3 670km2. The property extends for 100 km in an east‐west direction and varies between 28 km to 46 km in width. The northeast corner of the property comes to within 17 km of Huambo.

The Longonjo REE prospect is the first target within the Ozango Project to be drill tested by Rift Valley Resources.

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