Philex completes in-phase plan for Silangan project

MANILA, Philippines — Philex Mining Corp. has completed the in-phase feasibility study for the Boyongan deposit of the Silangan Copper Gold project.

In a disclosure to the Philippine Stock Exchange, Philex said the Boyongan deposit, which covers the first phase of the project’s development, has a mineable reserve of 81 million tons.

“The resulting updated mineable reserve estimate below is the culmination of the in-phase mine plan feasibility study undertaken,”Philex said.

The company said a feasibility study for a four million tons per year sub-level cave mining plan for the Boyongan copper porphyry deposit was previously completed and disclosed in 2019, which was used as the basis for the in-phase mine plan feasibility study.

The in-phase plan consists of the development of a starter sub-level cave mine that has an annual ore production of 700,000 tons or 2,000 tons per day.

“Mining will commence at the east sub-level cave because it has the highest grade ore. A new decline will be developed to access the east sub-level cave while the existing exploration decline will be rehabilitated to serve as an alternative mine access and a ventilation exhaust for mine air,”Philex said.

It said ore coming from the starter mine would be hauled using mine trucks from underground to the process plant at the surface, where it will be crushed and ground to required sizes.

“Copper, gold, and silver will be recovered using copper leaching and gold leaching processes because the ore at this point consists of predominantly oxide minerals,”Philex said.

The processing plant will produce a London Metal Exchange (LME) grade copper cathode and gold-silver dore.

“Tailings from the processing plant will be piped to the tailings storage facility, which is five kilometers to the northwest of the Boyongan ore body,”Philex said.

The company said the 2,000 tons per day starter mine would last for five years. The mining and processing rate will be increased to 4,000 tons per day or 1.3 million tons per year in the sixth year of production.

By the ninth year, ore production and processing rates will again increase to 8,000 tons per day or 2.7 million tons per year.

A copper flotation circuit will be added to the process plant as the ore mined now consists of oxide and sulfide minerals,”Philex said.

This will produce copper concentrates with gold and silver.

Philex said the final ramp up would occur on the 12th year at 12,000 tons per day or four million tons per year.

The life of the mine for phase 1 Boyongan is 28 years and is expected to produce 2.8 million ounces of gold and 993 million pounds of copper during its mine life.

The initial capital cost to develop the starter mine is estimated to be $224 million, which will be spent within the 2.5 years development period.

Philex chief finance officer and treasurer Romeo Bachoco earlier said that the $224 million funding would be financed by a combination of capital infusion from the company, equity via stock rights offer (SRO) and debt.

The company is set to begin the development of the first phase of the Silangan project this year, which covers the Boyongan deposit.

The mine is targeted to commence commercial operations in the first quarter of 2025.