Defense Metals Corp. (TSXV: DEFN | OTCQB: DFMTF | FSE: 35D) has announced that it has received assays from its hydrometallurgical pilot plant. Interpretation of the data is largely complete. Defense has used data from Phase I to optimize the design conditions for Phase II of its pilot plant.
“Phase I of the hydrometallurgical pilot plant operation went very well and gave us the opportunity to explore areas of the flowsheet where we could further improve the efficiency of the Wicheeda hydrometallurgical process. Changes have been incorporated in the Phase II pilot plant campaign, which started yesterday and will run for about ten days..” commented John Goode, consulting metallurgist for Defense Metals.
Minor changes were made during Phase I of the pilot plant testing to investigate the impact on circuit operability, extraction, impurity removal, and product quality.
The acid bake kiln reduced operation heat from 350ºC to 250ºC as there was no obvious impact on REE extraction, fresh water was used in the water leach circuit for the initial part of the pilot plant run but was switched to regenerated water for the last portion, with no discernable adverse effect. Industrial grade magnesia proved more effective than regenerated magnesia in the neutralization and impurity removal in the water leach circuit. Magnesia will also be switched to oxalic acid as the precipitant for the next phase of pilot testing.
“The importance of pilot plants like the one we are operating cannot be overemphasized. It provides the opportunity to see if processes are stable and can be effectively controlled; to determine the effects of in-plant recirculation of solutions and solids; measure recoveries and reagent demands; and generates significant quantities of material that can be used for engineering design and environment-related tests. The data from the pilot plant will be used in the pre-feasibility study.” Added John.
Defense Metals has selected the engineering company Hatch to undertake parts of the PFS and Hatch will attend the pilot plant going forward.
For further information please visit: www.defensemetals.com
