Environmental stewardship is a priority

We are committed to continuously improving our environmental performance and operating in compliance with applicable legislation as minimum requirements.

Our dedicated environmental and operations teams work closely on daily operations, expansion proposals and long-term closure requirements to integrate environmental considerations into mine plans.

We focus on prevention and learning to set opportunities to implement best practices, as well as set progressive annual objectives to drive continuous improvement.

Case Study

Enhancing tailings management at Cozamin

Capstone has been safely and responsibly operating Cozamin’s tailings storage facility (TSF) since 2006.

In 2020, Capstone made the decision to convert this TSF from a conventional wet storage facility to a dry stack facility. With this change, tailings in the facility will retain significantly less water than they have in the past and this will greatly decrease water consumption and reduce risks to mine personnel, local communities and the environment. This type of approach to risk minimization associated with tailings storage is one of the Principles of the Global Industry Standard on Tailings Management.

Capstone will also use approximately half of Cozamin’s tailings to produce a cemented paste that will be pumped underground to be used as mine backfill material. This will decrease the required footprint of surface tailings storage and improve the long-term stability of underground mine workings. Engineering consultants, who have expertise in dry stack tailings design and paste backfill systems, have completed feasibility-level design of these systems. Both the dry stack TSF and paste backfill system are expected to come into operation in 2022.

Our approach to tailings management

Since 2019, Capstone works with an experienced tailings engineer to oversee tailings management at all of our operations, and to work collaboratively with our sites, consultants and other stakeholders to continuously improve our tailings management. Their mandate includes supporting the overall strategic direction of the company and guiding the technical support function across all Capstone sites.

We are committed to the preservation of water resources and to continually reduce our environmental footprint. Pinto Valley continues to aggressively implement water

conservation measures and to pursue alternate water sources to sustain mining operations. Recent projects include increasing the amount of water recovered from tailings before delivering them to tailings storage facilities, thereby decreasing overall water use needs. Cozamin operates their tailings thickener to allow 75% of the water used in the mill to be recovered for use by the mine. This reduces the mine’s water consumption and improves the geotechnical and environmental performance of the tailings facility.

Case Study

Pinto Valley

Pinto Valley’s environmental impact statement

Mining is a highly regulated activity. In most jurisdictions, new mines or expansions are subject to a formal environmental assessment that includes stakeholder consultation. In 2020, the US Forest Service completed an Environmental Impact Statement (EIS) for our proposed expansion of Pinto Valley Mine. Potential impacts identified in the EIS will be mitigated and monitored through requirements that become part of the Mine Plan of Operation approved by regulators. These correspond to areas Pinto Valley is actively managing as part of current operations.

Deploying water-saving technologies at Pinto Valley

After experiencing drought conditions in 2020, Pinto Valley increased efforts to find technology solutions. We were able to use information from our water balance model (see above) to improve the way we manage water in the milling process. This is based on a key finding that we were losing considerable water to evaporation from the slurry coming out of mills and going to the tailings dam.

In 2020, we also completed a successful pilot test using Eriez HydroFloat technology in our mill. The technology allows for coarser grinding of rock, which makes particles settle more quickly and allows us to recover more water before it evaporates. This method has other environmental benefits as well: coarser grinding uses less energy. In the long term, the Eriez HydroFloat technology also has the potential to give us more flexibility in tailings management strategies and better water recoveries in the milling process.

Environment Awards & Recognitions

2015 - 2020
Cozamin mine has been awarded the Clean Industry Certification by Mexico's Federal Attorney for Environmental Protection (Procuraduría Federal de Protección al Ambiente or PROFEPA) every year.

Case Study

Cozamin

Improving safety at Cozamin with a one-way ramp and ventilation shaft

In 2021, we completed major projects that will improve production at Cozamin, and vastly improve underground safety.

First, we installed a Calicantro one-way ramp, which will vastly improve the safety of our underground mine. In previous years, production at Cozamin was capped due to high levels of two-way haul traffic that used the same ramp to enter and exit the mine. By utilizing a one-way ramp, we alleviate traffic congestion, greatly reduce vehicle-to-vehicle hazards, and increase production levels. In addition, an 818m ventilation shaft was completed, bringing fresh air flow to the deepest areas of the mine, and improving overall temperatures. Excessively high temperature is a contributing factor to worker fatigue and has been noted as a factor in some safety instances.

h these two projects, we have reduced hazards and enhanced ventilation. They are just some of the ways we are continually working to significantly improve safe working conditions of the mine.

Safety Awards & Recognitions

2020
Cozamin received the Health Security badge from the Mexican Institute of Social Health (IMSS)
2019
Capstone Mining’s Corporate Exploration Team received the Prospectors and Developers Association of Canada (PDAC) Safe Day Everyday Bronze Award