PHILEX Mining Corp. has estimated 81 million metric tons (MT) of mineable reserve for the Boyongan deposit of its Silangan copper-gold project in Surigao del Norte, it told the stock exchange on Wednesday.

“After incorporating standard mining factors to the mineral resource, the competent person for this report has delineated 81 million tons as mineable reserve,” the listed mining company said  in a disclosure.

Philex announced the estimated reserve after it completed the feasibility study of the in-phase mine plan, which calls for a starter sub-level cave mine.

Philex said the initial capital cost to develop the starter mine is estimated to be $224 million, which will be spent within a development period of two years and six months. It said the starter sub-level cave mine has an annual ore production of 700,000 MT or 2,000 MT 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 in the disclosure.

The 2,000-MT-per-day starter mine will last for five years. On the sixth year, the mining and processing rate will increase to 4,000 MT per day or 1.3 million MT annually.

By the ninth year, rates will increase again to 8,000 MT per day or 2.7 million MT annually. A copper flotation circuit will also be added to the plant by the ninth year as ore will consist of oxide and sulfide minerals.

The final ramp up will occur on the twelfth year, where ore production rate will be up to 12,000 MT per day or 4 million MT annually.

In 2019, the company released a feasibility study for a 4 million-MT-per-year sub-level cave mining plan for the Boyongan copper deposit, which has a mine life of 28 years. This consisted of a starter sub-level cave mine with an annual ore production of 700,000 MT or 2,000 MT per day.

Philex shares rose 3.56% or 18 centavos to finish at P5.24 apiece in the stock exchange on Wednesday.

Philex is one of three Philippine units of Hong Kong-based First Pacific Co. Ltd., the others being Metro Pacific Investments Corp. and PLDT, Inc.

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