Mina Real | Rochester Resources Ltd.

01 · Overview

Two properties in Nayarit, Mexico.

The Mina Real Property consists of 11 mining concessions and one mineral claim. The San Francisco Property consists of twelve mining concessions.

The terrain is rugged and steep, with deeply incised valleys and elevations from 800 to 1,600 metres above sea level. The climate is sub-tropical, with a dry and a wet season.

Company

Since 2007

Operating continuously in Mexico

Company

100%

Interest in Mina Real México SA de CV

Holds the Mina Real and San Francisco properties, Nayarit

Company

21,367 ha

Mina Real Property

11 mining concessions and one mineral claim (21,367.42 hectares)

Company

18,125 ha

San Francisco Property

Twelve mining concessions (18,125.05 hectares)

At present there is no Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) or National Instrument (“NI”) 43-101 compliant Resources or Reserves for the Mina Real Property or the San Francisco Property.

The Company has conducted mining operations without defined mineral resources and the production decision was not based on a feasibility study of mineral reserves that has demonstrated technical or economic viability.

A mining study to establish the technical feasibility and economic viability of the Mina Real Property has not been completed nor does the project host a mineral resource. As a result there is increased uncertainty and risk of economic and technical failure.

02 · History

Operating continuously since 2007.

2007The Mina Real processing plant begins treating mineralized material from the Estanzuela Unit.
2014Additional material from the San Francisco Unit. Today substantially all material comes from the San Francisco Unit.
Q1 2024A process using certain reagents that could improve silver and gold recoveries is identified.
2024Laboratory testing with the University of Guanajuato, a three-month industrial pilot, engineering, permitting, procurement and construction of the new circuit.
Oct 2024Plant modifications to increase silver recovery begin.
Mar 21, 2025The new circuit commences operations.
Jun–Aug 2025First phase of the plant modifications completed (fiscal Q1 2026).
Oct–Dec 2025The 6′ × 5′ mill goes out of service; a used 6′ × 6′ mill is rebuilt and installed, and begins operating in late December 2025.
Fiscal 2026Silver recovery of 66.70% and gold recovery of 99.60%, on 43,042 tonnes processed (year ended May 31, 2026).
Oct 2026Larger pretreatment tank expected to be completed (mid to late October).

Cholita mine portal, San Francisco project

03 · The problem

Manganese kept silver out of reach.

Like many long-running silver operations, Mina Real’s mineralized material carries a naturally high manganese content.

Manganese occludes silver and interferes with conventional cyanide leaching, which has historically limited silver recovery.

Historical

~43%

Historical silver recovery baseline

Illustrative only, not to scale. Proportions reflect the historical baseline (~43%) and industrial pilot results (62% mine mineralized material, 56% tailings). How the pretreatment works is not shown.

04 · The opportunity

Already mined. Already crushed.

Over the many years of operation, the company has accumulated significant tonnage of mineralized material in its tailing impoundment areas.

The upgraded mill can now deal with the higher manganese content. Processing this material is a focus for fiscal 2027, and the company is working to finalize a processing plan.

05 · 2024

Research and development.

In 2024, the company focused its efforts on finding a solution to the impact of manganese on silver recoveries. A laboratory testing program, in partnership with the University of Guanajuato, evaluated mine mineralized material, tailings, and blends of both.

It identified a pretreatment combining ammonia bisulfite and sulphuric acid ahead of conventional cyanidation. The results were positive, with substantial improvements in recoveries.

Plant laboratory micro-balance for weighing gold and silver

06 · Industrial pilot

Confirmed at the plant.

A follow-up three-month industrial pilot at the plant confirmed the lab work.

Silver recovery at the plant

Historical baseline, industrial pilot and reported fiscal-year results

Historical baselineSilver recovery before the new process~43%

Industrial pilot: mine mineralized materialThree months at the plant62%

Industrial pilot: tailingsThree months at the plant56%

Fiscal 2025Reported, year ended May 31, 202552.98%

Fiscal 2026Reported, year ended May 31, 202666.70%

Fiscal-year figures are reported plant results from the MD&A for the year ended May 31, 2026. Gold recovery was 99.60% in fiscal 2026 (fiscal 2025: 96.76%). Pilot figures are from a three-month industrial pilot.

07 · Engineering

From concept to a full-scale circuit.

Building on those results, Mina Real commissioned a conceptual engineering study for a full-scale circuit.

Design capacity

500 tpd

Tailings, tons per day

Design capacity of the full-scale circuit

Design capacity

160 tpd

Fresh mineralized material, tons per day

Design capacity of the full-scale circuit

Estimate

~US$4M

Estimated capital cost

Conceptual engineering study estimate

08 · Construction

Built, then started up in March 2025.

The project moved through engineering, permitting, procurement and construction, with plant modifications beginning in October 2024. The initial phase cost approximately US$1.45 million, and the new circuit commenced operations on March 21, 2025.

Company

Mar 21, 2025

New circuit commenced operations

Plant modifications began in October 2024

Company

~US$1.45M

Initial phase of plant modifications

Approximate cost, news release March 24, 2025

09 · Plant

Plant upgrades.

With the design in place, the company carried out a comprehensive revamp of the plant.

Ball mill · 6′ × 6′

After the 6′ × 5′ mill went out of service in October 2025, the company sourced a used 6′ × 6′ mill, rebuilt and installed it, with a corresponding slurry pump upgrade. It was commissioned and began operating in late December 2025.

Centrifugal decanter

A high-speed centrifugal decanter for liquid-solid separation, installed and started up, recovers water, residual values and cyanide for reuse.

Water recovery

Water is recovered by the centrifugal decanter for reuse.

Cyanide recovery & reuse

Cyanide is recovered for reuse, cutting fresh reagent consumption.

Electrical substation

A new electrical substation, with a 750 kVA transformer and compact substation installed.

Tailings filtering station

An expanded tailings filtering station, enabling dry-stacked tailings storage.

Dry-stacked tailings

Tailings stored dry-stacked, rather than wet.

New 18,500-litre stainless-steel ammonium bisulfite tank

Stainless-steel process tanks

New stainless-steel process tanks, including two reagent tanks with stainless-steel piping and pumps, an acidity/basicity control tank, and a new 18,500-litre stainless-steel tank for ammonium bisulfite.

Crushing circuits

Primary, secondary and tertiary crushing circuits revamped, including repairs to the jaw crusher and the 4 ft and 3 ft cone crushers.

Drum filters

Existing drum filters fully rehabilitated. On vacuum filter no. 2, damaged steel was replaced, filter screens changed and the filter drive rebuilt.

Ball mill · 6′ × 12′

Babbitt bearing replaced on the 6′ × 12′ ball mill.

Precipitation

Two new Butters filters constructed for the precipitation circuit.

Laboratory

A micro-balance for weighing gold and silver installed and in operation.

10 · Mine

Mine upgrades.

Mucking & hauling equipment

New mucking and hauling equipment brought into the mine.

Water pumping stations

Mine water pumping stations rehabilitated, including cleaning of sump 018.

New pumps

New pumps installed, including a 40 HP pump at sump 018.

Electrical systems

Mine electrical systems upgraded.

Compressors in the generator and compressor area

Compressed-air systems

Mine compressed-air systems upgraded.

11 · Results

Better recoveries.

Reported result

66.70%

Silver recovery, fiscal 2026

Year ended May 31, 2026. Fiscal 2025: 52.98%

Reported result

99.60%

Gold recovery, fiscal 2026

Fiscal 2025: 96.76%

Reported result

211,110 oz

Silver produced, fiscal 2026

Fiscal 2025: 166,754 oz

Reported result

4,977 oz

Gold equivalent produced, fiscal 2026

Fiscal 2025: 3,873 oz

The results have been positive, with improvements in both silver and gold recoveries. In fiscal 2026 (year ended May 31, 2026), silver recovery was 66.70%, up from 52.98% in fiscal 2025, and gold recovery was 99.60%.

Revenue rose to $25,946,223 from $13,288,820, and the company recorded operating income of $3,450,767 compared with an operating loss of $1,233,841 in fiscal 2025, aided in large part by improvement in commodity prices. The company recorded a comprehensive loss of $2,671,558 for the year, compared with $2,319,102 in fiscal 2025; the increase was primarily attributed to a fluctuation in foreign exchange.

12 · Tailings

Filtered and dry-stacked.

An expanded tailings filtering station allows tailings to be stored dry-stacked rather than wet. The dry-stacking upgrade also reduces the operation’s environmental footprint.

A centrifugal decanter recovers water, residual values and cyanide for reuse, and the water and cyanide recovery system cuts fresh reagent consumption.

13 · Next

What’s next.

The company is completing the addition of a larger pretreatment tank by mid to late October 2026, which will allow for increased capacity through the mill.

An additional mining contractor has been hired to work on the Mina Real properties, with the objective of increasing the tonnes processed. The contractor has established operations and tonnes processed are increasing.

Expected

Oct 2026

Larger pretreatment tank: expected completion

Mid to late October 2026. Expected to allow increased capacity through the mill