Metallurgy

MDA’s technical report summarized the results of preliminary metallurgical testwork carried out on both sulphide and oxide mineralization. G&T Metallurgical Services Ltd. tested a series of bulk composites constructed from samples taken from across the resource base to develop a flotation treatment plan for sulphide mineralization. Initial open-circuit testwork provided criteria for subsequent locked-cycle procedures to confirm recoveries and concentrate grades. The results can be summarized as follows:

• a conventional differential flotation process would be used to generate two concentrates from sulphide mineralization
• a zinc concentrate grading 52.5% zinc with recoveries up to 95% depending on feed grade
• a copper concentrate grading 32% copper with a recovery of 50%
• indium, gold and silver will be recovered to the concentrates
• the concentrates do not contain deleterious elements at penalty levels
• the mineralization is of moderate hardness, with a work index of 13.2
• potentially profitable amounts of magnetite may be recovered from flotation tailings
• additional metallurgical testwork is warranted to optimize recoveries and various process elements

Kappes, Cassiday & Associates completed a series of leach and concentration tests on a composite of the oxide zinc mineralization constructed from samples taken from a number of Lithic’s drill intercepts. Initial sulphuric acid leach testing of this composite showed significant extraction of zinc (up to 95%), copper (up to 78%) and indium (up to 37%) to solution. No work was completed to determine the process method and resulting recovery of metals from the acid solution. However, there are proven technologies available that will be evaluated in future test programs.