Cerro de Pasco Resources (TSXV: CDPR; WKN A2N7XK) reports significant progress on its massive, polymetallic tailings reprocessing project Quiulacocha in the central highlands of Peru. Following an extensive Phase 1 program involving drilling, metallurgical tests, and environmental studies, the company is now preparing for the transition to Phase 2 – with the goal of both economically utilizing and permanently remediating historical, primarily silver-rich tailings.
The Quiulacocha project is considered one of the most strategically important undertakings for metal recovery from legacy waste in Peru. Cerro de Pasco aims to unlock the immense potential of tailings accumulated over decades while simultaneously improving the environmental footprint of the traditional mining region.
Cerro de Pasco Resources: Phase 1 Program Lays Technical Foundation
As part of Phase 1, Cerro de Pasco Resources completed a 40-hole sonic drilling program on the Quiulacocha tailings area. The results confirm metal grades and continuity in the drilled area and form the basis for a future resource estimate of the tailings. In parallel, international tenders are already underway for Phase 2 drilling, which is intended to complete the data package for the initial resource estimate.
A key focus of the program is on mineralogy and metallurgy. Intensive testing is currently underway in several laboratories in Sweden, the USA, Chile, and Peru to determine how
Concurrently, extensive environmental baseline data has been collected. The wet season has been fully documented, and dry season investigations are ongoing. These include water quality measurements, biological surveys, geochemical and geotechnical sampling, and hydrogeological monitoring programs. Drone-supported LiDAR, magnetic, and photogrammetry measurements provide high-resolution terrain models.
Rheology and abrasivity tests on ten composite samples show that the Quiulacocha tailings can be pumped at solids contents of 65% to 75%. This opens up the possibility of cost-efficient, dredge-based recovery (dredging) with hydraulic transport to a new final tailings area.
According to Cerro de Pasco Resources, the company is fully funded for Phase 2 drilling and ongoing test programs. Next milestones include the formal securing of claims to the entire tailings area, the completion of the integrated metallurgical program in the first quarter of 2026, and the submission and approval of the necessary drilling permits (DIA or FTA) for Phase 2.
Regulatory Framework: Key Developments for Quiulacocha
A central element of the latest update from Cerro de Pasco Resources is the progress on permits and responsibilities. In November 2025, the independent Mining Council – the highest mining authority in Peru – published two resolutions that more clearly define the further administrative process for Quiulacocha.
The decisions state that a formal agreement between Cerro de Pasco Resources, as the holder of the core permit El Metalurgista, and the state, as the bearer of historical environmental responsibility, is required for comprehensive reprocessing of the entire tailings area. At the same time, the path is outlined by which the Ministry of Energy can review and formalize the tailings reprocessing application.
For the company, this clarification means that the involved authorities – the Mining Council, the Ministry, and state agencies – now have a unified reference framework. CDPR reports ongoing discussions with the Ministry of Energy and expects the permitting process for Phase 2 drilling and the expansion of reprocessing rights to gain further momentum.
In parallel, Cerro de Pasco Resources has already submitted the Phase 1 results report to the authorities. This document links drilling data, environmental baselines, and technical studies, serving as a basis to proceed to the next permitting stage and formalize tailings-related rights beyond the El Metalurgista concession.
Metallurgical Tests and Resource Estimation in Focus for Cerro de Pasco Resources
On the technical side, Cerro de Pasco Resources is working on an integrated metallurgical program, which is scheduled for completion in the first quarter of 2026. Mineralogical investigations – including quantitative mineralogy, sequential extractions, electron beam analyses, and laser-ICP-MS – serve to understand mineral associations, metal distribution, and factors influencing recovery rates.
Based on this, representative composite samples are being prepared according to metallurgical domains. Initial flotation tests have already produced base metal concentrates as well as pyrite concentrates, in which a large portion of the silver is carried. Downstream cleaning stages are intended to optimize grade and recovery. Due to the very fine particle sizes of the tailings, only minimal regrinding is required, which brings potential operational and energy cost advantages. In parallel, CDPR is testing specialized processes for the flotation of very fine particles.
Initial leaching tests show that silver and gold can be selectively dissolved into a separate product stream. For the pyrite concentrate, the company is investigating whether it can be sold directly or further processed into sulfuric acid. Overall, the work aims for a multi-product flow sheet solution that maximizes metal recovery and significantly reduces the volume of final residual tailings.
Concurrently, Cerro de Pasco Resources is preparing the Phase 2 drilling program. A total of approximately 116 boreholes are planned across the entire Quiulacocha tailings storage facility. The drilling is intended to complete geological, hydrogeological, and geotechnical datasets, provide one-meter-long samples, and thus create the basis for the initial resource estimate of the tailings. International drilling companies with amphibious platforms and sonic drilling capabilities are to be employed. The start is planned after approval of the expanded reprocessing rights.
Environment, Remediation, and Long-Term Perspective of the Quiulacocha Project
In addition to metallurgical and geotechnical work, Cerro de Pasco Resources clearly positions Quiulacocha as an environmental and remediation project. The completed wet season baseline study and ongoing dry season survey include water quality, geochemistry, biological surveys, and physical site data. These datasets will be incorporated into the subsequent Environmental Impact Assessment.
Drone-supported surveys covering more than 5,000 hectares – with high-resolution LiDAR, photogrammetry, and regional magnetics – form the basis for hydrogeological models and digital elevation models. Initial stability analyses, plate load tests, sampling, and SCPTu measurements help identify risks and align planning, infrastructure, and long-term tailings strategy.
Various options for remining and final disposal were evaluated in so-called trade-off studies. In addition to technical feasibility, storage capacity, land use, hydrology, and environmental aspects are in focus. The selection of a preferred long-term tailings storage facility is a central building block on the path to the pre-feasibility study.
With its 100% owned El Metalurgista concession area, Cerro de Pasco Resources pursues the goal of reprocessing historical tailings, recovering silver and other critical metals such as gallium, and simultaneously remediating legacy waste. The company aims to establish Quiulacocha as a reference project for responsible tailings reprocessing, environmental remediation, and sustainable value creation in Peru.
