Mega Precious Metals Provides Positive Metallurgical Results for the Monument Bay Project
Press Release
October 2, 2014
Mega Precious Metals Inc. (MGP:TSX-V) (“Mega”) is pleased to announce positive results from the ongoing metallurgical work being completed by Thibault & Associates Inc. on the conceptual open pit within the Twin Lakes Deposit at the Monument Bay Project. The metallurgical program results will be included as part of Mega’s upcoming maiden gold and tungsten NI 43-101 Resource Estimate and for future Preliminary Economic Assessment (“PEA”) work.
The preliminary metallurgical recovery results suggest overall gold recoveries of 90.3% which were achieved using standard conventional milling processes. Further to this, Thibault and Mega have developed very competitive operating costs for the various process scenarios under consideration based on a Dynamic Economic Model (DEM) AACE Class V. These preliminary mill operating costs were defined for extraction of gold mineralization from 5,000, 10,000 and 18,000 tonne/day milling rate scenarios.
Highlights of the Preliminary Metallurgical Process:
- Overall gold recoveries of 90.3% which includes recovery from a bulk sulphide concentrate, extraction in Pressure Oxidation Leaching (“POX”)/Cyanidation and recovery of gold in a CIP Circuit. (See table 1)Dynamic Economic Model (DEM) estimated process operating costs (“OPEX”) for gold dore production between CAD $10.10-$15.35/tonne. (See Table 2)
- Bulk sulphide concentrate has a mass pull of 5.4% of the process ore with a small POX circuit i.e. a small amount of ore creates the concentrate
- Dynamic Economic Model (DEM) estimated process operating costs (“OPEX”) for gold dore production between CAD $10.10-$15.35/tonne. (See Table 2)
The company is currently completing additional gold and tungsten metallurgical tests to further optimize gold and tungsten recoveries.
Glen Kuntz, P.Geo, President and CEO, stated “We are pleased to have defined excellent overall gold recoveries that are amenable to well established milling scenarios. The milling scenarios have been designed to incorporate Manitoba’s power costs (currently some of the lowest in North America) of between C$0.02-C$0.04 k/hr. The combination of high recoveries and low power costs creates a competitive DEM processing cost model estimate which is quite favourable for the ongoing economic evaluation and optimization work. We are also pleased with the progress we are continuing to make surrounding the tungsten processing and recoveries. The final process and overall tungsten recoveries will be determined after additional metallurgical analysis is completed. These calculations will form the basis for our upcoming technical reports”.
The process for the recovery of gold and tungsten is based on the testing completed to date and is illustrated in the overview block diagram (Figure 1). The process concept takes advantage of selective mining of the Gold-Tungsten Zone separately such that additional processing requirements for tungsten by-product recovery are applied to a smaller tonnage size to minimize costs. The gold-bearing, bulk sulphide concentrates are combined and processed for gold recovery in a common process. To maximize recoveries, the process design is based on conventional pressure oxidation of the bulk sulphide concentrate followed by cyanidation and final gold recovery by carbon adsorption, stripping, electrowinning and refining.
Two options are being considered for tungsten recovery. The first option is illustrated in the block diagram (Figure 1) whereby tungsten is recovered from bulk sulphide flotation tailings by scheelite rougher flotation with cleaner flotation and acid leaching to upgrade the final concentrate to 65% WO3 grade. An alternative conceptual scenario considered for tungsten production involves the production of a lower grade (30% WO3) concentrate without acid leaching of impurities, followed by hydrometallurgical processing of the concentrate to produce ammonium paratungstate (APT). The final process and overall tungsten recoveries will be determined after additional metallurgical analysis is completed on both options.
Preliminary Metallurgical Recovery
Based on the degree of definition of the process to date, the overall estimated recoveries of gold were selected using process test data where available and typical assumptions as required. Bench scale data is based on composite test samples processed to date. Input parameters were entered into the process flowsheet simulation that calculated the overall recoveries based on a closed circuit operation.
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