Strike Minerals reports +/- 95% initial mill gold recovery test results
Wednesday, Jan 23, 2013
Strike Minerals Inc. (TSX VENTURE:STK) ("Strike" or the "Company") announces initial mill testing of mineralized material from the Edwards #1 vein at its Edwards Mine project in Jacobson township near Wawa, Ontario.
The Company engaged Activation Laboratories Ltd. ("Actlabs") to determine the gold beneficiation characteristics in respect to gravity concentration and flotation of the samples provided by Strike Minerals.
The first was a Gravity Recoverable Gold Test (GRG) on a Knelson Concentrator. The GRG test is a widely accepted industry test used to determine the theoretical maximum amount of gold that can be recovered by gravity. Five flotation tests were performed on samples with 5 different collectors/promoters to determine which reagent suite gives better recovery and grade.
The results of the GRG indicate that cumulatively 77.57% of the gold in the sample is able to be recovered by gravity concentration, which indicates an ore highly amenable to gravity concentration methods. With a single pass through the concentrator, a lower volume of concentrate was collected and the recovery of gold was lower at 67.5%. However a lab-scale Knelson concentrator has a much smaller area for concentrate collection and a full-scale model should be able to achieve recoveries similar to that obtained in the GRG test.
A number of flotation reagents were examined and considered for testing. With the desire to use the flotation tailings as backfill material, environmentally friendlier chemicals were researched. It was determined though that, since only very small dosages of flotation collectors are used and only a very small portion of collector would remain with the tailings slurry and even less once the backfill has been dewatered, the choice of collector should focus on gold recovery achieved. These test indicated that gold flotation would result in a 95.29% gold extraction.
The recovery of gold using only flotation resulted in a recovery of 95.3% and the combination of gravity and flotation yielded an overall recovery of 94.7%. Although similar, the concentrate grade achieved by gravity and flotation concentration was double that of simple flotation and therefore may be the better option if direct smelting or sale of the concentrate is desired.
This test work was undertaken to provide Strike details on the beneficiation performance of its ore in the continuing development of the Edwards mine project. The results can be provided to existing mills to determine the parameters for negotiation of a custom milling agreement. The results can also be used by Strike to prepare a flow-sheet and mass balance calculations for the design of its own milling facilities. Strike is in the initial stages of the identification and sourcing of mill processing equipment to construct a 200 tpd facility on site.
Strike has also taken one full lift on the Edwards #1 vein resulting in approximately 300 tonnes of muck. This material will be sampled and added to the surface stockpile. Back sampling along the 23.3 metre vein length prior to blasting averaged 24.45 g/t Au over a 1.5 metre width.