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.

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 ........