Tag Archives: Martabe

Green Gold to test cyanide reduction tech on Poseidon’s Windarra gold tailings project

Poseidon Nickel says it has signed a binding heads of agreement with Green Gold Projects Pte Ltd (GGP) for the processing of the Windarra Gold Tailings Project in Western Australia.

The agreement could see Green Gold deploy its patented technology at the project, which includes ReCYN, which, through the use of a resin-bead absorbent, can reduce cyanide consumption by 50%, capturing free cyanide from the plant tailings and recycling it back into the leach circuit while recovering metal complexes and making them available for sale.

In the process, ReCYN detoxifies the tailings stream and guarantees 100%-compliant clean water discharge, according to Green Gold.

Its technology is already being tested at PT Agincourt Resources’ Martabe gold-silver operation in Sumatra, Indonesia, to detoxify tailings and recover cyanide and copper.

The binding agreement outlines the proposed partnership with GGP for the processing of the tailings, with a final agreement subject to GGP being satisfied with the outcome of metallurgical test work and a bankable feasibility study being completed at GGP’s expense.

The Windarra Gold Tailings Project consists of the Windarra and Lancefield (pictured) tailings with combined mineral resources of 5.96 Mt at 0.84 g/t Au and 2.1 g/t Ag, containing 180,000 oz of gold. A definitive feasibility study (DFS) was completed by Poseidon and released in mid-2021, which investigated using two different mining methods on the Windarra tailings, amphibious dredging or hydraulic mining and the construction of a modular 1.5 Mt/y processing plant to recover up to 55,000 oz of gold over a 45-month period.

The economic analysis indicated a project with an net present of circa A$20 million ($13.5 million) and internal rate of return of 45-50% depending on the mining method, assuming a gold price of $1,750/oz and an exchange rate of A$1 to US$0.75.

“While the outcome of the DFS was positive, the company is focused on the restart of the Black Swan project and decided that finding a partner to develop and operate the Windarra Gold Tailings Project was the best outcome for shareholders,” Poseidon said. “This process commenced earlier in the year and significant interest was received from various parties.”

Poseidon Nickel Managing Director and CEO, Peter Harold, said: “This agreement (with GGP) is a significant milestone in the company’s strategy to monetise the Windarra Gold Tailings Project. Green Gold Projects is an experienced developer and operator and is currently active in 30 projects globally.”

Upon achieving the test work and feasibility study milestones, GGP will earn a farm-in interest in the project. In return, Poseidon will receive consideration in the form of cash payments – upfront and upon project financing and a free carried profit interest of 8%. The funding, development and operation of the project will be the responsibility of Green Gold.

“The proposed partnership with Green Gold is an ideal outcome for Poseidon given our focus on the development of our nickel projects,” Harold said.

GGP was selected as the preferred partner given its experience as a developer and operator of similar projects, Poseidon said. Its patented technology has the potential to improve the economics of the project, according to the company.

The binding agreement outlines certain conditions to be met to reach a final agreement to develop the project. These include:

  • Metallurgical test work performed by GGP on the Windarra and Lancefield tailings to determine if its patented technology can improve gold recovery;
  • The rights and obligations of the Lancefield tailings right-to-treat Agreement are assigned to GGP; and
  • GGP receiving Foreign Investment Review Board and any other anticipated approval if required.

Subject to the satisfaction of these pre-conditions, Poseidon will grant GGP the right to farm-in to the project subject to the completion of the following milestones:

  • Milestone 1: GGP making a non-refundable upfront payment of A$250,000 upon satisfying the pre-conditions mentioned above to earn an initial 13.8% interest in the project;
  • Milestone 2: GGP completing a positive bankable feasibility study on the project to earn a further 13.8% interest in the project; and
  • Milestone 3: GGP making a final investment decision, securing funding for the project, and making a non-refundable payment of A$1 million to Poseidon to earn a further 64.4% interest in the project.

Poseidon will then retain an 8% free carried profit interest in the project, which entitles the company to 8% of the profit while not contributing to any capital or any other payments. The binding agreement also specifies that the project must be in production within three years from the date that the last farm-in milestone is satisfied, and that GGP will be solely responsible for meeting any rehabilitation or other environmental liabilities arising from the project.

GreenGold’s ReCYN to detoxify tailings, recover cyanide and copper at Martabe

Technology provider GreenGold says it has been awarded a ReCYN™ design and install contract with PT Agincourt Resources to detoxify tailings and recover cyanide and copper at its Martabe gold-silver operation in Sumatra, Indonesia.

Jakarta- and Perth-based GreenGold will deliver the project with preferred fabricators for specialist equipment packages, the company said.

In a report published last year, Whittle Consulting called the ReCYN process “a world-leading approach” in cyanide recovery, metal recovery and tailings detoxification. “Based on an innovative resin-bead absorbent, ReCYN reduces cyanide consumption by 50%, capturing free cyanide from the plant tailings and recycling it back into the leach circuit while recovering metal complexes and making them available for sale,” Whittle said.

Whittle also said adopting the technology could provide a $126.9 million upside to the project.

GreenGold said it had received the contract following a record influx of enquires for the technology.

GreenGold CEO, Malcolm Paterson, said of the Martabe contract: “We have come up with an elegant design to fit the space constrained site. We also will be recovering cyanide and copper which previously was destroyed or sent to tails, turning a cost into an economic benefit for the mine.

“We are looking forward to delivering on this strategically important project, and continuing to build on our proven metallurgy and process capability within the precious/base metals sector globally.”

The Martabe mine has a resource base of some 7.4 Moz of gold and 69 Moz of silver.