The Mount Hope Deposit is a classic molybdenum porphyry, typified by the deposit at Climax Colorado. This type of deposit has well zoned molybdenum (moly) mineralization where the grade zoning surrounds the central zone of the deposit and forms geometries that are circular in plan and arch shaped in section.

Mount Hope differs from Climax in that the multiple mineral centers are adjacent horizontally rather than juxtaposed over the same porphyry center. The centers of mineralization are referred to as the east and west mineral systems. The eastern and western mineral systems each contain mineral shells at least 3,300 ft in diameter, and the two systems are centered about 2,300 ft apart along a west-northwest axis. The mineral zones or “shells” consist of quartz stockwork veining that contains molybdenite that is hosted within both porphyry and sedimentary units.

The main form of molybdenum mineralization is molybdenite (MoS2), developed within the porphyritic igneous rocks and in the Vinini hornfels adjacent to the southern margin of the igneous rocks. Much of the known molybdenite is distributed around two mineralized systems consisting of two dome shaped zones of mineralized stockworks. These zones are shaped like inverted bowls along an east-west trend. The two systems form east and west mineral systems that intersect each other.

The western mineral system is characterized by a triangular distribution of molybdenum grades in plan view with well-defined grade zones. Mineralization is best developed in the southern and eastern quadrants of this system. The center of the system is directly above the western quartz porphyry intrusive stock.

The eastern mineral system contains well-developed mineral grade shells in quartz porphyry above the eastern porphyry stock. In the northwest quadrant of the system, these shells are continuous with mineralization of the overlap zone. The apex of the mineral system has, however, been sliced off and faulted down and eastward along the Mount Hope Fault. The offset fault mineralization is theorized to lie above the fault.

A concentration of higher-grade mineralization is present between the eastern and western mineral systems. Referred to as the overlap zone, this zone is roughly 1,300 ft in diameter and varies from 325 to 985 ft thick. The top is 325 ft below the ground surface. This zone is the nucleus of the open pit target. Overlap mineralization lies beneath the Mount Hope Fault, and the upper, eastern edge is truncated by the fault surface. The overlap zone is interpreted as a rock volume that was mineralized by both mineral systems in sequence, contributing to a greater intensity of stockwork veining and additive molybdenum grades.

A conventional hard rock open pit mine plan was developed for the Mount Hope deposit based on the block model of the mineralization. The mining process will use standard open pit mining techniques of drilling, blasting, loading, and hauling of ore and waste to the crusher and waste storage facilities.

The mine is planned to deliver a nominal 66,688 t/d of sulfide flotation ore to the crusher.

Low-grade material between the mill cutoff and a lower stockpile cutoff is stockpiled for later processing in years 34 through 41. The total material rate for the first 15 years of the mine life starts at 97,207 kt/yr and ramps up to 112,564 kt/yr (266,320 to 308,395 t/d). The rate decreases from year 16 through the end of the mine life.

The following items summarize the process operations required to extract molybdenum from the Mount Hope ore:

- Crush the ore with a primary gyratory crusher to reduce the ore size from run-of-mine (ROM) to minus 6 inches (150 mm).

- Stockpile primary crushed ore and then reclaim with feeders and conveyor belt.

- Reduce the size of the ore in a semi-autogenous (SAG) mill - ball mill grinding circuit prior to processing in a flotation circuit. The SAG mill will operate in closed circuit with a SAG mill trommel screen and a vibrating screen. The ball mills will operate in closed circuit with hydrocyclones.

- Produce a molybdenite concentrate by the flotation process. The molybdenite flotation circuit will consist of rougher flotation, followed by six stages of cleaning in mechanical flotation cells. A flotation column will be included as a contingent 7th cleaning stage, in case the concentrate of the 6th cleaner bank fails to meet the final concentrate grade requirement or impurity specifications.

- Dewater and dry the final cleaner flotation concentrate and transport it to either packaging or the roaster circuit. Alternatively, the final cleaner flotation concentrate may be leached in a ferric chloride leach circuit to remove copper, lead, and zinc impurities, if they are above acceptable limits in the concentrate. The leached concentrate will be dewatered, dried, and transported to either packaging or to the roaster circuit.

- Roast the molybdenite concentrate in a multiple hearth roaster to produce technical grade molybdenum oxide. The molybdenum oxide will be transported to product packaging and packed in containers for shipment.

- Off-gas from the roaster will be treated to remove particulates, SO2, and SO3. Off-gas treatment equipment will first clean the gas by removing particulate matter using cyclones and electrostatic precipitators. Following gas cleaning, a lime scrubber will remove sulfur oxide gases. A bleed stream from the lime scrubber system will be sent to the tailing impoundment.

- Dewater the flotation tailing in thickeners and pump the tailing to a tailing impoundment area.