Vancouver-based Aris Mining Corporation (TSX: ARIS) (OTCQX: TPRFF) will be significantly accelerating its gold production at a Colombian mine following approval from domestic authorities for its underground development.
The company announced Wednesday that it had obtained permission from the country’s Regional Autonomous Corporation of Caldas (a regional environmental authority) to develop the Marmato Lower Mine.
The establishment of the new underground mine will grant entry to the extensive porphyry mineralization beneath the existing upper portion of the mine, enabling the utilization of large-scale mining techniques in the lower section. Combined, the upper and lower areas of Marmato contain a 6 million ounce (Moz) mineral resource of measured and indicated gold, including a proven and probable reserve of 3.2 Moz.
Production from the Marmato Mine is expected to average 162,000 ounces per year throughout a mining lifespan of approximately 20 years, utilizing the identified mineral reserves.
“This is a milestone for Aris Mining as it will grow Marmato’s gold production five-fold and, following construction, our Colombian gold production from Segovia and Marmato will be approximately 400,000 oz per year,” said Neil Woodyer, CEO of the company.
Woodyer says the project is valued at $280 million and is fully funded from a combination of the company’s cash balance and $122 million in stream funding from Wheaton Precious Metals Corp. (TSX: WPM).
“This permitting of a new, underground gold mine is a significant achievement for Aris Mining, the Marmato community and the Colombian gold mining industry,” added Woodyer.

Diagram showing the depth of the upper and lower mineralization at the Marmato Mine. Image via Aris Mining
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The addition of the underground mine at Marmato will enable Aris to process an additional 4,000 tonnes of ore per day. However, the mill that will process that amount of ore on a daily basis isn’t scheduled for mechanical completion until Q3, 2025.
All of the land for the project’s construction has been secured by the company but it is still in the process of bidding on certain necessary items such as a gold room and an oxygen plant, with orders expected to be placed in Q3 this year.
Aris will be constructing the road leading to the new processing facility, mine portal and declines in Q4 this year once that infrastructure has been established. Additionally, the company says it will be constructing a 32-kilometre 115-kilovolt transmission line on an inclusive “buy build operate” basis to supply power to the underground mine and other facilities.
Aris has appointed Vancouver’s engineering consultant Ausenco as the engineering, procurement, construction and management contractor for the processing facility.
Aris Mining stock rose by 0.63 per cent on Wednesday to $3.20 on the Toronto Stock Exchange. As of July 11, the company had 137.2 million issued and outstanding shares.
Aris also operates the Segovia mining operation, which is expected to produce between 200-230 kilo ounces this year.

Colombian portfolio. Photo via Aris Mining
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