Dec 4 2014
West Kirkland Mining Inc. today announces that a bulk run-of-mine column test of 12 tons of mineralized material from the Three Hills deposit achieved 81.1% gold recovery after 133 days of leach and rinse; 75% of the gold was recovered after 100 days of leach.
The column tests were performed by Kappes Cassiday & Associates, Reno, to determine the gold recovered from run-of-mine material. Run-of-mine refers to ore sized as it would be after drilling and blasting without further crushing. Previous test work indicated similar recoveries but had been performed on 1-1/2 inch crushed material. A 20 ton sample was collected from three surface cuts at Three Hills, 12 tons of which was used in the four-foot diameter by 24-foot high test column. Bottle roll tests on the bulk sample were compared to bottle roll tests on a core sample at six different elevations throughout the deposit. The results indicated a similar metallurgical response.
"The potential removal of crushing costs at Three Hills is significant as it can reduce capital and operating costs in the critical early years of the project," says Sandy McVey, West Kirkland's Chief Operating Officer.
West Kirkland purchased both the Three Hills and Hasbrouck deposits using a base case assumption of USD$1,000 gold, with crushing assumed at both deposits. "Given the 81% run-of-mine recovery results, as well as the current volatile gold and commodity market, our conservative initial assumptions have proven prudent," says McVey. The results of the test will be incorporated into the ongoing Three Hills and Hasbrouck prefeasibility study.
Images of the bulk sample test work can be viewed on the Company website at www.wkmining.com or from the following link: http://wkmining.com/projects/gallery1/.
In contrast to Three Hills, test work at the Hasbrouck deposit indicates that the more the rock is crushed the greater the gold recovery. West Kirkland is currently testing the use of high pressure grinding rolls (HPGR) technology at Hasbrouck as a way to increase gold and silver recovery from the heap leach. West Kirkland expects HPGR test results in the coming weeks.
Previous metallurgical studies indicating 60% gold recovery at a 3/8 inch crush were used in the internal base case modelling at Hasbrouck. The potential financial savings from run-of-mine leaching at Three Hills may be directed towards the increased capital cost involved in increasing the recovery at the larger Hasbrouck deposit. Increased gold recovery from the test work will be compared in a trade-off study against increased capital for the HPGR crushing.
Three Hills is the smaller of the two deposits making up the Hasbrouck Project and will be the first brought into production. West Kirkland recently started the formal permitting process by submitting a Plan of Operations for Three Hills to the Bureau of Land Management, just seven months after acquisition (see news release dated November 25, 2014).
West Kirkland's independent consultants, Mine Development Associates, are completing a prefeasibility study which will incorporate the recent metallurgical studies. Prefeasibility results are expected in the first quarter of 2015.