Stacker/Sizer Operator

About Mariana Minerals

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.

Position Summary:

The Equipment Operator plays a critical operational role in supporting mine production through the safe and efficient operation of heavy equipment, including stackers and sizers.

This position is responsible for conducting equipment inspections, maintaining safe working conditions, contributing to production targets, supporting operational and maintenance teams, and ensuring compliance with MSHA standards and company procedures. The ideal candidate demonstrates strong situational awareness, mechanical aptitude, and the ability to work effectively in a dynamic mining environment.

Housing can be provided onsite.

Essential Duties and Responsibilities:

Operational Responsibilities

· Safely operate heavy equipment including stackers and sizers.

· Work across all mine areas as needed, including active pits, dumps, haul roads, and process areas.

· Operate equipment in a manner that maximizes productivity while minimizing downtime, fuel use, and equipment wear.

· Perform and document accurate pre‑shift and post‑shift inspections on all assigned equipment.

· Conduct ground support tasks such as shoveling, spotting, barricading, and general labor when required.

· Assist maintenance personnel by communicating equipment issues, supporting troubleshooting, and performing basic servicing.

· Maintain clean, safe, and organized operating areas.

Safety & Compliance

· Always follow MSHA, OSHA, and company safety procedures, including lockout/tagout, hazard reporting, and traffic rules.

· Demonstrate strong hazard recognition skills and actively participate in daily safety meetings.

· Ensure equipment operation and ground activities comply with environmental and regulatory expectations.

· Report unsafe conditions, equipment damage, and near misses immediately.

Collaboration & Communication

· Communicate effectively with supervisors, maintenance, and fellow operators.

· Provide clear shift handover notes to ensure continuity between crews.

· Participate in task training for new operators and support continuous improvement initiatives.

Required Qualifications & Experience:

· Experience operating heavy equipment, preferably stackers, sizers, screen plant or conveyors.

Ability to learn and apply federal, state, local, and company safety and environmental regulations.

· Strong written and verbal communication skills.

· Willingness to perform manual labor as needed.

· Flexibility to train on additional equipment and roles.

· Compliance with all company policies and procedures.

· MSHA Surface Miner Training preferred.

· Commitment to maintaining a safe work environment.

· Must possess or be able to obtain a valid driver’s license.

Physical Requirements

· Ability to walk long distances over rough, uneven terrain and climb ladders and structures.

· Ability to lift a minimum of 50 pounds.

· Ability to work in all weather conditions, including extreme temperatures.

· Must wear and utilize all required PPE.

· Must be able to work in environments that may include exposure to fumes, dust, diesel, solvents, sulphuric acid, and other hazardous materials.

Our culture is built on four principles:

Everyone Gets Home Safe. We never put speed or cost ahead of people.

Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.

Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.

Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.

Join us as we build the future of responsible mineral sourcing and supply!