Erdene Resource Development Reports Q2 2026 Gold Production and Advances Khundii District Projects

• Bayan Khundii Gold Mine produced and sold 11,709 ounces of gold in Q2 2026, a 37% increase over the previous quarter
• Gold sales generated US$53 million in revenue, with recoveries of 96%, above the planned 93%
• Average processed ore grade rose 25% quarter over quarter
• Updated mineral resource estimates were completed across the Khundii district, including a maiden estimate for the Ulaan deposit
• Maiden drilling at Tereg Uul, near the Oyu Tolgoi copper-gold system, intersected gold and silver mineralisation along a 1.5 kilometre structure

Erdene Resource Development Corp. (TSX:ERD; MSE:ERDN; OTCQX:ERDCF) is a Canada-based mining company that operates the Bayan Khundii Gold Mine in Mongolia through a joint venture with Mongolian Mining Corporation. The company also holds a group of precious and base metal projects across the surrounding Khundii Minerals District.

Bayan Khundii Gold Mine Production Reaches 11,709 Ounces, Generating US$53 Million in Revenue at 96% Recovery

Bayan Khundii produced and sold 11,709 ounces of gold and 3,317 ounces of silver in the second quarter of 2026, a 37% increase in gold ounces compared with the first quarter. The mine achieved weighted average prices of US$4,493 per ounce of gold and US$72 per ounce of silver, generating total revenue of US$53 million (C$75 million) against a total cost of revenue of US$24 million (C$33 million). Erdene holds a 50% economic interest in the mine.

The mine processed 153,000 tonnes of ore at an average rate of 1,682 tonnes per day, with an average feed grade of 2.4 grams of gold per tonne, a measure of how much gold is contained in each tonne of ore mined, around 25% higher than in the first quarter. Gold recoveries, the proportion of gold successfully extracted from the ore, reached 96%, above the planned 93%, while throughput ran at 94% of target. 

Peter Akerley, Erdene's President and CEO, said:

"We delivered another quarter of improved performance, achieving gold production of 11,709 ounces at Bayan Khundii, a 37% increase over the previous quarter, driven by stronger mining performance and continued steady operation of the process plant. The average processed ore grade rose 25% during the quarter, reflecting enhanced ore control and mine-to-mill practices that significantly reduced dilution and ore loss."

At the corporate level, Erdene recorded net income of C$9,993 thousand for the quarter, compared with a net loss of C$4,122 thousand in the same quarter last year, when the mine was still under construction. The company also repurchased 94,400 shares at an average price of C$5.21 under a share buyback programme launched during the quarter.

Updated Mineral Resource Estimates Cover Multiple Khundii District Deposits, Including Maiden Ulaan Estimate, as Zuun Mod Study Advances Toward Mid-H2 2026 Completion

Erdene prepared updated mineral resource estimates, calculations of how much gold and other metals are likely contained within a deposit, for several of its Mongolian projects during the quarter. These included revisions to the Bayan Khundii, Dark Horse and Altan Nar deposits to account for ore already mined, recent exploration work and current gold prices. The company also completed a maiden mineral resource estimate for the Ulaan deposit, located immediately west of Bayan Khundii.

Work also progressed on the preliminary economic assessment, a study that estimates the potential costs, scale and economics of developing a project, for the Zuun Mod molybdenum-copper project. Mine planning, marketing and metallurgical test work are largely complete, with the assessment on track for release in mid-H2 2026. Erdene has also signed a contract for a deep geophysics exploration programme at the nearby Khuvyn Khar project, due to begin in late Q3 2026. 

Mr Akerley said:

"Technical work is well advanced on the Zuun Mod preliminary economic assessment, expected to be released in mid-H2 2026 with geophysics and drilling planned later this year to test the copper potential of the Khuvyn Khar project on the license."

The Ulaan estimate adds a newly quantified deposit near existing mine infrastructure, while the upcoming Zuun Mod assessment will provide the first detailed economic study of Erdene's molybdenum-copper project.

Maiden Tereg Uul Drill Program Confirms Anomalous Gold and Silver Along 1.5 Kilometre Structure Near Oyu Tolgoi

Erdene completed its first drill programme at the Tereg Uul property, located approximately 10 kilometres south of the Oyu Tolgoi copper-gold mine. The programme comprised 11 holes totalling 2,710 metres. Eight shallow holes at the Web prospect intersected anomalous gold, above 0.1 grams per tonne and up to 1 gram per tonne, and silver of up to 15 grams per tonne, along a mineralised structure extending 1.5 kilometres.

Deeper drilling aimed at a geophysical target intersected a coal seam within 150 metres of surface, along with traces of native copper mineralisation. Following these results, Erdene extended its option agreement over the Tereg Uul property for a further year in July, with a US$400,000 option payment. 

Mr Akerley said:

"At the Tereg Uul property, adjacent to the Oyu Tolgoi copper-gold system, our maiden drill program confirmed anomalous gold and silver mineralization along a 1.5 kilometre trend at the Web prospect, while deeper drilling intersected native copper and anomalous gold."

The property sits within the same district as Oyu Tolgoi, one of the world's larger known copper-gold systems, and adds to Erdene's exploration holdings alongside its producing gold mine and base metal projects in the Khundii district.

Milestones and Next Steps

Erdene will host a conference call and webcast on August 17, 2026, to discuss the quarter's results. The Zuun Mod preliminary economic assessment remains on track for completion in mid-H2 2026, and the deep geophysics programme at Khuvyn Khar is set to begin in late Q3 2026. At Tereg Uul, the extended option agreement covers further evaluation of the Web prospect and deeper copper targets. Erdene's share buyback programme, which allows for the repurchase of up to 4,900,000 shares, around 10% of its public float, also continues.

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