Philex Mining Corporation, one of the largest producers of copper and gold in the Philippines, reported that the Boyongan deposit of Silangan copper-gold mine project in Surigao del Norte may yield $7 billion in gold and copper over 28 years.

In a disclosure to the Philippine Stock Exchange, the firm said this is based on a feasibility study conducted on the Silangan copper-gold mine project.

Philex unveiled the financial assumptions behind the company’s decision to pursue the In-Phase development of the Silangan Project, which will start this year and will cost the company an initial investment of $224 million.

The starter mine that will initially produce 2,000 tons of ore per day will begin commercial operation in early 2025 and reach 12,000 tons a day by the 12th year of operation.

“The numbers for the Silangan Project are very compelling, pushing us to pursue the mine development even without a strategic partner or major investors as we originally envisioned,” said Philex Chief Finance Officer Romeo Bachoco.

The Boyongan deposit alone of the Silangan Project has an estimated 81 million tons of mineable reserve that is estimated to yield 992.8 million pounds of copper and 2.81 million ounces of gold.

The estimated mineable reserve is based on Philex’s In-Phase Mine Plan for Silangan. Philex is still exploring the nearby Bayugo deposit.

The feasibility study assumed a price of $3.20 per pound of copper and $1,342 an ounce for gold—both below current prices of copper of over $4.00 per pound and of gold that is over $1,800 an ounce.

Using those assumed prices, the combined revenues from copper and gold totaled to $6.91 billion over the 28 years life of the soon-to-be-developed mine.

Bachoco said earlier that the break-even cost of producing a pound of copper in Silangan is between $2.00 and $2.30 per pound and between $850 and $900 for every ounce of gold.

Aside from the $224 million needed to develop the starter mine, Philex had earlier reported that total sustaining capex investment over the mine life of Silangan will reach around $1.5 billion, which will be mostly funded from Silangan’s internal cash generated from commercial operations.

Philex will raise the initial capital for the starter mine from a combination of proceeds from a planned stock rights offer, a fresh capital infusion from surplus cash of Philex from its current Padcal mine operation to its wholly-owned subsidiary Silangan Mindanao Mining Co.—the company that will operate the mine, and possibly debt.

Philex said the stock rights offer, which is scheduled in February, subject to the approval of the PSE and Securities and Exchange Commission, will raise around P3.15 billion for the Silangan Project.