Copper Flat is a porphyry copper-molybdenum deposit that is approximately 1,400 by 2,100 ft in plan occurring within a small structurally controlled quartz monzonite stock that has intruded a circular block of andesite approximately 4 miles in diameter. The porphyry includes a variably mineralized west-northwest-trending hydrothermal “breccia pipe,” that lies immediately south of the Patten fault, that is about 1,400 ft long and 500 ft wide.

Copper Flat has been categorized as an alkalic copper-gold bearing breccia pipe, surrounded by and genetically linked to an alkalic porphyry system. The deposit is situated along the eastern edge of the Cretaceous Arizona-Sonora-New Mexico porphyry copper belt and along with Tyrone, New Mexico, forms a linear mineralized feature known as the Santa Rita lineament (SRK, 2010; McLemore et al., 2000). Analogous deposits include Terrane Metal’s Mount Milligan, British Colombia deposit and the Continental breccia pipe located in the Central Mining district of New Mexico (SRK, 2010).

Although copper occurs almost exclusively as chalcopyrite locally accompanied by trace amounts of bornite, minor amounts of chalcocite and copper oxide minerals are locally present near the surface and along fractures. The supergene enrichment typical of many porphyry copper deposits in the Southwest is virtually non-existent at Copper Flat. During the early mining days, a 20- to 50-ft leached oxide zone existed over the ore body, but this mate ........

The Copper Flat Project is planned for production using conventional hard rock open pit mining methods. Ore production to the mill is planned at 29,600 tpd (10,800 ktons/yr) for the first 6 years followed by 27,125 tpd (9,900 ktons/yr) for the remaining mine life. The mine production schedule was developed with the goal of filling the mill at required ore rate and maximizing the project return on investment. The total material rate is tied to equipment productivity and amounts to 17,500 ktons/yr or 47,945 tpd for the first 5 years. The mine is scheduled to operate 365 days/yr with two, 12-hour shifts/day.

Bench heights are planned at 25 ft high. Drilling will be completed with three rotary blast hole rigs with 45,000 lb pull down capacity and 6.5 in diameter blast holes. The blasted rock will be loaded into 100-ton haul trucks using two 19 cu yd front end loaders.

Three phases were designed for the Copper Flat Project with approximately 300 ft of operating width on each bench within a phase. Phase 1 was sized to contain roughly 1.5 years of ore.

Mine Planning Parameters:
- Haul Road Width - 90 feet;
- Haul Road Grade - 10% Maximum;
- Inter-ramp Slope Angles: 0° to 90° Northeast - 41 degrees, 90° to Brec Southeast - 39 degrees, Breccia - 36 degrees, Brec to 360° West - 44 degrees;
- Operating width between pushbacks - 300 feet nominal.

- subscription is required.

The Copper Flat Project will produce copper and molybdenum flotation concentrates. The design basis for the conventional sulfide flotation mill is a throughput of 30,000 dry short tons per day or 10,800,000 dry short tons per year for approximately 12 years with reductions in throughput in Years 6 through 12 projected due to the mineralization becoming more difficult to grind.

The process selected for recovering the copper and molybdenum minerals is considered “conventional.” The sulfide ore is crushed and ground to a fine size and processed through mineral flotation circuits.

The process operations required to extract copper and molybdenum from the Copper Flat sulfide ore:

- Size reduction of the ore by a primary gyratory crusher to reduce the ore size from run-of-mine (ROM) to minus 175 mm.

- Stockpiling primary crushed ore and then reclaiming by feeders and conveyor belt.

- Grinding ore in a semi-autogenous (SAG) mill primary g ........