Overview

Deposit type

• Skarn
• Breccia pipe / Stockwork
• IOCG

Summary:

East Deposit
The East Deposit, located 7,000 ft east of the North Deposit, measures approximately 2,000 ft by 1,200 ft and consists of flat-lying to gently dipping, bedding-controlled, stacked skarn-IOCG mineralized zones within the limestone of the Mason Valley Formation at depths of 1,400 to 2,200 ft. The East Deposit is defined by drill holes spaced approximately 175 to 250 ft apart.

Higher grade copper occurs mainly in dolomitized limestones and skarn-chalcopyrite-magnetite-pyrite breccias immediately adjacent to diorite or diorite endoskarn. Much of the high magnetite rock that grounds the East Deposit is within diorite endoskarn. A good amount of continuity is evident in the East Deposit with mineralization possibly continuing and thickening to the west. The area between the East Deposit and the North Deposit still requires detailed exploration to accurately determine the lateral extent of each Deposit.

E2 Deposit
The E2 Deposit is a steeply northwest-dipping lens of high grade copper-magnetite skarn-IOCG breccia within the Mason Valley limestone, which lies on the hanging wall of an endoskarn sill. The lens has been explored along approximately 1,200 ft of strike length, is 40 to 120 ft thick, and is locally continuous for at least 1,600 ft down-dip.

The chalcopyrite-magnetite mineralization follows the marble front, similar to the East Deposit. A major east-trending rotational fault appears to exist between the two deposits and results in a significant variation in the deposit orientation. Analysis of the drill hole intersections suggests that the E2 Deposit may, in fact, be a series of steeply dipping, plunging shoots, as much as 400 ft wide and 3,000 ft long on dip. The main portion of the mineralization starts approximately 800 ft below the present surface and extends 2,400 ft below the surface.

Mining Methods

- subscription is required.

Comminution

Crushers and Mills

Summary:

The underground process plant has been designed to process 5,000 stpd of copper ore. The plant and the unit operations therein are designed to produce a marketable concentrate targeted at 26.0% Cu, or greater. The proposed underground process plant is expected to achieve an estimated 92% Cu flotation recovery. Gold recovery is expected to be 78% and silver recovery is expected to be 70%. Concentrate moisture is expected to be <10%, and tailings cake moisture is expected to be <15%. The plant will consist of a coarse ore storage facility, a SAG mill, a semi-autogenous ball mill crusher (SABC) comminution circuit, rougher flotation, regrind circuit and cleaner flotation, to liberate, recover and upgrade copper from underground ore. Flotation concentrate will be thickened, filtered and sent to a concentrate load-out stockpile for subsequent transport/shipping. Dry stack tailings (DST), in conjunction with underground paste backfill, are the preferred means of final deposition, having substantially less water contained than tailings discharged directly from a concentrator. DST will be produced by thickening and filtering the final flotation tailings. The underground paste backfill portion of the tailings will be thickened, classified, filtered and combined with cement before being deposited in the underground mine workings. Thickening and filtration of tailings allows better process water management and control. Process water will be recycled from the tailings and concentrate thickener overflows. Fresh water will generally be used only for pump gland service, mill lube cooling, SAG mill ring motor cooling, reagent preparation, and safety showers / eyewash stations.

Processing

- subscription is required.

Production

Personnel

Mine Management

Source

Job Title	Name	Profile	Ref. Date
.......................	.......................		Jan 2, 2024
.......................	.......................		May 2, 2024
.......................	.......................		Jan 2, 2024