In 2007, CESL conducted exploratory tests to investigate copper and gold hydrometallurgical extractions. The tests used the CESL proprietary leaching technology, including pressure oxidation of the copper concentrate followed by pressure cyanidation of the copper leach residue. Two-thirds cleaner bulk copper-molybdenum concentrates produced from the PRA test work, assaying 26.3 and 24.9% copper, were used for the testing. The preliminary tests produced high copper extractions in the range of 96 to 98%, indicating that Schaft Creek copper concentrates were amenable to the CESL process. These copper extractions were achieved at 15 to 30 minutes of retention time as compared to a typical requirement of 60 min normally required for a chalcopyrite concentrate.

Pressure cyanidation tests extracted between 89 and 92% of the gold and between 81 and 88% of the silver from the copper leach residue. Sodium cyanide consumption was approximately