Deposit Types The mineral deposit type at the FCP site is a Laramide-age porphyry copper deposit consisting of a large core of copper sulfide mineralization underlying a zone of copper oxide mineralization. The central portion of the deposit is overlain by approximately 400 feet of flat-lying conglomerate and alluvial material that contains a fine-grained silt and clay interbed. The oxide and sulfide zones are separated from one another by a transition zone of mixed oxide-supergene sulfide ranging from 0 to 55 feet in thickness. The depth and grade of the sulfide zone renders it currently uneconomic to mine by conventional mining methods. The impermeability of the rocks and insoluble mineralization of the sulfide zone renders it uneconomic for ISCR methods. Approximately 71% of the oxide mineralization is hosted by a Precambrian quartz monzonite and 26% by Tertiary granodiorite porphyry. The remaining igneous rocks associated with the deposit are Precambrian diabase and Tertiary andesite, latite, dacite, basalt, and aplite. The deposit occurs in a structural horst block, which is bounded on the east and west by grabens and is controlled by normal faults trending north to northwest. Mineralized Zones The mineralized zones consist of an iron-enriched leached cap, an oxide zone, and an underlying sulfide zone. In most instances, the transition from the copper silicates and oxides to the sulfide zone is quite abrupt. A majority of the copper oxide mineralization is located alo ........

The extraction method proposed for the Florence Copper Project is in-situ copper recovery (ISCR). ISCR extracts copper by injecting a weak sulfuric acid solution called raffinate through targeted portions of the mineral deposit using an array of injection wells. The raffinate passes through natural fractures and voids in the deposit and dissolves the copper mineralization. The copper laden solution, known as pregnant leach solution (PLS), is collected in recovery wells where it is pumped to the surface for processing. Copper is extracted from the PLS using solvent extraction and electrowinning techniques (SX/EW) producing a saleable copper cathode product and raffinate for recirculating into the well field. Following the copper extraction sequence, the depleted reserve areas are rinsed to remove the remaining process solutions and restore ground water quality to prescribed standards. The ISCR stages are scheduled progressively allowing the first areas extracted to be rinsed and closed while other areas of the well field are under development.

In-situ recovery methods have been used successfully in the mineral extraction industry for over 50 years as an alternative to open pit or underground mining methods for mineral deposits with amenable geological and hydrological properties. In-situ recovery does not require physically handling the mineralized material, overburden, or non-mineralized rock and, consequently, this method does not require many of the activities ty ........

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