Woodlark Island (locally known as Muyuw Island) is located on the northern margin of the Woodlark Basin, some 600 km east of Port Moresby.

There are some series of gold deposits at the Woodlark Project: Kulumadau, Busai, Woodlark King, Munasi.

The geology of the island consists of basement Palaeocene-Eocene tholeiitic basalt and sediments (Loluai formation) overlain by mid- Miocene calc-alkaline to shoshonitic volcanics (Okiduse formation), which host the majority of known gold mineralisation. The island is relatively flat, with the highest point, Mt Kabat just 243 m above sea level. Most of the island is covered by a Pleistocene age coral reef formation (Kiriwina formation), masking prospective volcanic sequences.

Busai and Kulumadau are both interpreted as structurally controlled epithermal gold deposits. The deposits show evidence of complex paragenetic assemblages and variable degrees of structural overprint. The main difference between the two deposits is the overwhelming amount of brecciation and cataclasis at Kulumadau as compared to Busai. Both deposits remain open at depth and along strike.

Due to the significant presence of post- mineralisation Kiriwina formation sediments masking much of the prospective geology, very little regional scale exploration exists.

The extensive resource drilling database, geophysical surveys and limited surface exploration all indicate the widespread occurrence of gold mineralisation well outside the defined resources. Major regional structures associated with known gold resources are evident on geophysical images and form the principal targets for exploration.

The project will involve open-cut mining of gold reserves at the Kulumadau, Busai and Woodlark King deposits using multi-staged pit designs, with a stripping ratio of 3.9:1 over the life of the mine. Waste rock will be deposited in engineered waste rock dumps located adjacent to each pit.

Mining Plus was engaged to complete the mining components of the DFS, including optimisation, design and scheduling and preparation of a detailed operating and capital cost estimate to enable the generation of an Ore Reserve.

The study has shown that the three mining areas can be developed in a practical sequence to mine 1.1 Moz of gold and provide sufficient feed to the processing plant for 13 years.

Pit Designs and Ore Reserve.
The Ore Reserve was generated from the Mineral Resource Estimate produced by MPR Geological Consultants with the appropriate modifying factors applied for dilution. This Resource model was used in an open pit optimisation process to produce a range of pit shells using operating costs and other inputs derived from all previous studies and then verified as the DFS was finalised.

Geotechnical drilling and analysis was completed by Peter O’Bryan and Associates to DFS level. The resultant recommended design parameters were used to approximate the overall pit slope angles for the pit optimisation runs, and the final wall angles for the designs.

The optimisation resulted in four discrete pits, two at Woodlark King and one each at Busai and Kulumadau.

Individual designs were completed for each discrete area of Busai and Kulumadau, plus a number of starter pits were designed to allow reduced pre-strip durations and the early access to high grades ore.

Mine Schedule.
The mine schedule was developed to ensure 2.4 Mtpa of ore is available to feed the processing plant once commissioned.

The initial pre-strip period is 9 months and involves the stripping of 5.5 Mt from Stage 1 and Stage 2 pits at Kulumadau and the build-up of 450,000 tonnes of ore on the stockpile at 1.45 g/t Au.

The planned mining rates are maintained below 10 Mtpa for the first three years of mining and then rise to 20 Mtpa by the sixth year. These mining rates are driven by the tonnage and grade requirement to ensure that the mine plan achieves gold production levels in excess of 100,000 oz per year for as long as practical.

The mining period is expected to last approximately 9 years excluding pre-stripping operations, however there is an additional four years of low grade stockpile reclaim after mining has been completed.

The process plant design for the Woodlark Gold Project is based on a robust metallurgical flowsheet designed for optimum recovery with minimum operating costs. The flowsheet is based upon unit operations that are well proven in industry.

The treatment plant design incorporates the following unit process operations:
• Primary jaw crushing to produce a coarse crushed product.
• A SAB milling circuit comprising a SAG mill and a ball mill in closed circuit with hydrocyclones.
• Gravity gold recovery and treatment of concentrate by cyanidation and electrowinning.
• A CIL circuit to leach and adsorb gold and silver onto carbon.
• A pressure Zadra elution circuit, electrowinning and gold smelting to doré.
• Dewatering of CIL tails slurry.
• Tailings slurry pumping via overland pipe to a deep sea tailings placement facility.
• The grinding circuit is fed directly from the primary crusher, i.e. there is no coarse ore stockpile or surge bin to decouple the grinding circuit and the crushing circuit. The plant utilisation factor has been set accordingly. An emergency feed hopper has been included to allow temporary feeding of the mill in the event of crusher downtime.