Previous metallurgical test work results were reviewed and it was concluded that whole mineralized material cyanidation with recovery of soluble gold by a CIP process is the preferred method for processing. Optimum retention times were found to be 24 hours at a grind size of 60% passing 74 microns (200 mesh), and expected average leach recovery of 90.6%.
Metallurgical processing data studied from the 2005 to 2007 milling campaign confirmed that during the last quarter of St Andrews Goldfields Ltd (SAS) operations in 2007 a gold recovery of 89.0% was achieved.
The mining methods selected for the Clavos JV project are cut & fill stoping and bulk long hole stoping with random pillars, for the most part, located in waste material. These stoping methods are considered to be inherently safe methods of mineralized material extraction.
The operating costs for stoping are provided below:
--------------------------------------------------------------- StopeDia. Drill Prep. Stoping Milling -------------------------------- Fill Back Excavation Prep. Fill --------------------------------$/t $ /t $ /t $ /t---------------------------------------------------------------CUT & FILL STOPING--------------$3.75 $ 12.50 $ 45.06 $ 7.39 $ 5.77 $ 30.00---------------------------------------------------------------LONG HOLE STOPING--------------$2.75 $ 8.75 $ 13.25 n/a n/a $ 30.00------------------------------------------------------------------------------------------------------------------------------------------- Unit UnitDia. Drill Trucking Cost G & A Services Cost ----------------------- Labour Operating$/t $ /t $ /t $ /t $ /t $ /t $ /t----------------------------------------------------------------------------CUT & FILL STOPING--------------$3.75 $ 4.00 $108.47 $ 10.50 $ 10.57 $ 5.70 $135.24----------------------------------------------------------------------------LONG HOLE STOPING--------------$2.75 $ 4.00 $ 58.75 $ 10.50 $ 10.57 $ 5.70 $ 85.52----------------------------------------------------------------------------
There are a number of milling facilities within the general area which, subject to favourable commercial arrangements, are considered to be suitable for processing the Clavos JV mineralized material.
Social and Environmental Setting
All environmental permits required for the Clavos JV project to produce a maximum of 700 tonnes per day have been received. The Closure Plan and financial assurance have been filed by the Director of the Ministry of Northern Development and Mines.
Future Upside
Continued underground mineral exploration and stope definition/delineation diamond drilling is an important part of the mining operation as detailed mine planning and layouts are dependent upon the availability of information on the grade and configuration of the mineralized structures encountered.
Underground exploration diamond drilling will commence as soon as the 250m level east heading has advanced 75 metres with intermediate diamond drill stations established and equipped each 60 metre interval stoping block definition/delineation diamond drilling will commence once the mine has been dewatered and rehabilitated sufficiently to commence with diamond drilling on 30m centers and 10m centers for detailed stope planning.
