Technical Report for the Maricunga Gold Mine - Kinross Gold

Kinross Gold CorporationMaricunga Mine Technical Report16.2 Metallurgical Test Work 200616.2.1 IntroductionGold recovery rates for the Verde and Pancho deposits have been estimated from test workconducted at McClelland Laboratories in Reno, Nevada. In 2003, a total of 9 column leachtests were done on 7 Pancho composite samples and 11 column leach tests were done on11 Verde composite samples. In 2006, an exploration drill program on the Pancho propertyprovided samples for an additional 14 column leach tests at McClelland. Final test data wasavailable by August 2007 and these gold recoveries have been integrated in the Panchoreserve estimate.16.2.2 Comments on Historical Metallurgical Composite Selection CriteriaThe early work on Maricunga metallurgical type classification established that the mostpredominant metallurgical criteria were grade, oxide state and crush size. The 1998metallurgical column testing relied on the classification of four groups of sample types largelypredicated by the amount of sheeted and stockwork veining as well as silicification. The fourgroups are outlined below.• Group 1 – 81.4% recovery – Strong sheeted veining, moderate strong stockwork,and weak matrix silicification.• Group 2 – 72.9% recovery – Moderate-strong sheeted veining, moderate stockwork,weak matrix silicification.• Group 3 – 66.1% recovery – Weak-moderate sheeted veining, weak stockwork, andweak to moderate matrix silicification.• Group 4 – 50.4% recovery – Weak-nil sheeted veining, weak-nil stockwork, andmoderate strong silicification.These groupings were specific to Verde, where East Verde was predominantly representedby Group 2, while West Verde was mostly comprised of Group 3.In 2003, the methodology for metallurgical sample selection was changed. Of concern wasthe issue that the head grades of the group 1 to 4 samples were 20 to 40% above averagegrade of the deposit and it was suspected that higher grade column samples would result inhigher gold recoveries. In addition, field geologists had concerns with the classification of66