- The project is a brown-field expansion of the existing heap leach-solvent extraction-electrowinning operation.
- The project execution is based on a Design and Construct philosophy with engineering managed by Finders and third party consultants.
- EPCM contract has been awarded to GR Engineering Services. Equipment will be delivered to site using chartered LCTs utilising Kuehne and Nagel for consolidation and freight forwarding of equipment and materials in Surabaya for transport to Wetar.
- Specialist contractors will be used for structural-mechanical-piping (SMP) and electrical and instrumentation (E&I) installation.
- Commissioning engineers will be provided by Australian company, PPM Global, which was responsible for commissioning of the original
- The total construction project duration is 15 months. First cathode production from the Kali Kuning Valley plant is 15 months from project start.
Waste Dumps & Earthworks
- The Kali Kuning area will require large volumes of bulk earthworks during the construction phase predominantly to prepare the leach pad, SX-EW plant and stormwater pond areas in the Kali Kuning Valley (KKV or KK Valley).
- The size of the fleet is designed to achieve the bulk earthworks tasks in line with the construction and production schedules. At peak activity periods the fleet would comprise 2 x 80t excavators and 14 x 40t articulated dump trucks plus support equipment. Equipment will be supplied by a mining contractor.
- Specialist earthworks designs for facilities such as the leach pads and process areas were designed by SRK and Golder Associates.
Mine Waste Rock Management
- Mining will commence at Kali Kuning (KK) and all waste rock produced, either from the pit or from construction earthworks, will be used as construction fill material.
- All of the potentially acid forming (PAF) waste rock will be used as fill in the base of the KK Valley pads. The remainder will be stored in the permanent waste rock dump at the head of the KK Valley.
- Wetar production follows a standard process flow sheet with crushed ore agglomerated and stacked on heaps. Heap aeration and irrigation allows leaching of copper into solution where it is collected and then extracted using standard SX-EW technology to produce copper cathode.
- The BFS adopts the same heap height and modular equipment proven during the Wetar demonstration phase, below:
Logistics & Infrastructure
- The Wetar project site is located in a remote area of east Indonesia however previous mining operations on Wetar Island have demonstrated that logistics will not impede operations. The mine site is only 6km by road from an established port.
- The transport of materials and mobilisation of heavy construction equipment for the demonstration plant construction was performed by large landing craft (LCT). This proved to be a safe and reliable mode of transport and LCTs can be berthed at the wharf facility which was designed specifically for these vessels.
- Surabaya is a key logistics base and a source of fuel for power generation. It will be the consolidation base for the mining fleet, spare parts and consumables prior to shipping by LCT.
- Copper cathode product will be shipped on the same LCTs to a warehouse in Surabaya for transhipment to international and domestic customers.
- Finders currently rents the former gold mine facilities from the government, including
- Roads : Kali Kuning access is operational. The Lerokis road will be upgraded.
- Accommodation Camp : Existing camp and messing facilities can accommodate up to 450 persons.
- Site Buildings : Existing offices and medical clinic will continue to operate as administration buildings. The explosive magazine is already operational. New process and mining offices will be located at Kali Kuning.
- Wharf & Landing Craft Facilities : The existing wharf can berth two 1,500t LCTs and also accommodate mooring and unloading of boats.
- New Infrastructure in the BFS includes MFO generator power station and fuel farm, HV power supply and distribution and raw water supply.