Rafaella Resources Limited announced the results of its phase 3 and Phase 4 metallurgical test work on the Santa Comba open pit ore being conducted as part of a Definitive Feasibility Study. Metallurgical Test Results and Sales Product: Metallurgical test work conducted by Grinding Solutions Limited in the UK has allowed a flowsheet to be developed for treating the disseminated wolframite ore from the Santa Comba open pit project. Extensive test work using industrial scale sorting machines have been carried out by TOMRA Sorting GmbH in Germany and remain consistent with those used in the Pre-feasibility Study (PFS), showing a 90% recovery with a 50% rejection of waste material from the +8 mm size fraction.

The key change from the PFS is an improvement in metallurgical recovery to a 15% concentrate (post ore sorting) from 70% to 76.2%. This has led to an overall increase in recoveries from the run of mine (ROM) to concentrate from 66% to 71.6%% (an overall increase of 5.6%). This is a significant improvement and opportunities remain to further optimise recoveries and drive down both capital and operating costs.

Sufficient study work has now been completed to finalise the process flow sheet (shown as an attachment to this announcement) and to complete the capital and operating cost estimates required for the DFS. This work is now well advanced. An important result of the metallurgical test work has been the final determination of the sales product.

Santa Comba will produce calcium tungstate (CaWO4), or synthetic scheelite, a premium product that typically achieves a payablility of 2% higher than the equivalent tungsten concentrate. Discussions with potential offtakers have confirmed the marketability of calcium tungstate and the Company is confident that offtake terms will soon be agreed. Process Flow Sheet: Sorting using X-ray transmission sorters allows waste to be rejected with only a small loss of tungsten (6.6%) and an increase in grade of 45%.

The upgraded ore will be milled using a rod mill with stacked sizers to close the circuit, and primary concentration will be achieved using a combination of continuous centrifugal concentrators and high intensity magnetic separation. The concentrate produced will be further upgraded using shaking tables followed by sulphide removal by froth flotation. The recovery of tungsten from sorter concentrate to a 15% WO3 concentrate is good at 76.2% with an overall recovery from ROM ore of 71.6%.

Initial test work has shown the tungsten can be leached using sodium hydroxide at atmospheric pressure and work carried out on similar ore achieved a 98% recovery of tungsten to high grade synthetic scheelite. Confirmatory leach /precipitation tests are currently being carried out. Flowsheets have been developed for all but the final leach /precipitation stage.

Equipment quotes have now been obtained and the development of a plant layout is almost complete.