Two distinct styles of manganese mineralization are observed on the Property: stratiform manganese deposits, and vein manganese deposits. The mineralization style responsible for the majority of manganese on the Property is stratiform manganese, which occurs within the Chapin Wash Formation. These deposits have typical grades of around 3% to 4% Mn and locally 6% to 10% Mn. Some workers interpret these deposits to be syngenetic with the host sediments, whereas others interpret remobilization of manganese and potassium by secondary metosomatic fluids. Some secondary redistribution of manganese occurred because of interaction with meteoric water.

Manganese also occurs within veins, breccias (some of which have been interpreted as possible volcanic vents), and fracture and fault zone cement, and overall this style of mineralization is referred as vein manganese. Mineralized veins are locally common within or near the stratiform deposits although they do occur in other units in addition to the Chapin Wash Formation, particularly within the Sandtrap Conglomerate. Vein manganese deposits are several million years younger than stratiform deposits, and although they are not obviously related, their spatial association does suggest some genetic link. Vein-type deposits are smaller, irregular and locally higher grade than the stratiform deposits and their size currently does not support large tonnage bulk mining practices.

Tetra Tech developed an open pit, truck shovel mine plan for the Artillery Peak manganese deposit, involving mining an average 7,000 t d of mineral resource and 17,220 t d of waste over a 21-year LOM. The mine plan will include a haul backfill system for co-disposal of all waste products within previously mined-out areas of the open pit. The annual MM production is set at 50,000 t a, with maximum processing rate of 2.55 Mt a. For the duration of the LOM, mineral resource containing 1,106,000 t of manganese will be delivered to the mill, for a recovered total of 994,499 t of recovered MM.

All mining operations will be performed by the Owner.

The open pit will be accessed through two-lane, 31 m-wide roads or ramps, at 10% maximum grade, to accommodate 136 t class haul trucks.

Equipment units were selected for operational flexibility, ore grade control and variable bench height for ore and waste. Off-highway rear-dump-haul trucks of 136 t capacity will be used for ore, waste and tailings haul. One 11.0 m3 diesel hydraulic face shovel will primarily be used for ore mining; excess loading capacity will be used to strip waste. Two 11.5 m3 wheel loaders will complement the hydraulic shovel in loading ore, and waste and in-pit backfill. Ore and waste rock material will require drilling and blasting.

A simple crushing circuit is designed to reduce the friable and clayey feed to a particle size suitable for downstream agitating leaching operation.

The ROM material will be transported from the open pit to the crushing facility by 136-t hauling trucks. The crushing circuit includes two crushers designed to process 417 t of ore per hour to a particle size of 80% passing finer than 2 mm.

The ROM ore is discharged onto a stationary grizzly. Material finer than 500 mm will flow by gravity into the crusher feed surge bin, and then be fed the sizer crusher at a controlled speed. The crushed material from the primary crusher will report to the secondary crushing feed bin, which will also receive the oversize of the secondary crushing screen. An impact crusher equipped with a 750 kW motor will be used for the secondary crushing to further crush the primary crusher discharge. The impact crusher will be in a closed circuit with a vibrating screen. The screen oversize material (coarser than 5 mm) will be recycled to the secondary crusher feed surge bin, while the screen undersize product will be directed by conveyors to two 7,000-t fine ore surge bins.

A dust collection system will be installed to control the spread of fugitive dust generated during the ore crushing and transport at the area. Magnets are provided over the surge bin feed conveyors to remove any tramp steels to protect the downstream crusher and conveyors.

In addition, a space at the primary crushing feed pad is provided for ROM ore emergency stockpiling.

The main equipment and facilities in the crushing circuit are:
• one sizer crusher (112 kW)
• one hydraulic rock breaker
• one secondary crusher feed bin (10 m3)
• one secondary crusher belt feeder
• one impact crusher (750 kW)
• one vibrating screen
• two fine ore surge bins, each 7,000-t capacity
• various belt conveyors.

The proposed processing plant is designed to process mill feed containing 2.2% to 3.5% Mn in the range of 3,500 t/d to 7,000 t/d, to produce 50,000 t/a of EMM at a purity of higher than 99.7% Mn and an overall recovery of 88 to 93% Mn. Anhydrous sodium sulphate will be produced as a byproduct.

The ROM mill feed will be trucked from the open pit to the crushing facility located at the plant site. Two stages of crushing will reduce the ROM feed to a particle size of 100% passing 5 mm. The first stage of the crushing will use a sizer crusher in an open circuit. The second stage of crushing will use an impact crusher in a closed circuit with a dry screen. The product from the crushing circuit will be stored in two 7,000-t surge bins prior to being conveyed to the leaching circuit.

The crushed mill feed will be leached in two stages: pre-conditioning leaching with acidic solution containing sulphuric acid (mainly recycled from downstream washing circuits), and sulphur ........