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.

Mariana Minerals is looking for a highly motivated Metallurgist to work on building back the domestic critical minerals supply chain.

As a Metallurgist at Mariana, you’ll play a critical role in supporting and optimizing our mineral processing operations across a range of unit processes, including heap leaching, solvent extraction and electrowinning (SX/EW), flotation, crushing, and milling. You’ll work closely with operations, technical services, and project development teams to ensure high metal recoveries, efficient reagent use, and safe, compliant plant operations. This is a site-based role with regular exposure to both fieldwork and metallurgical analysis. Expect a fast-paced, hands-on environment where your contributions directly influence production and growth.

What You’ll Do

Optimize Metallurgical Processes - Monitor and improve metallurgical performance across heap leach pads, SX/EW plants, flotation circuits, and comminution areas (crushing/milling). Identify bottlenecks, troubleshoot issues, and implement improvements to enhance throughput and recovery.

Design and Execute Test Program - Plan and supervise metallurgical testwork (e.g., column leach tests, flotation tests, grinding studies). Interpret results to support operational changes or project decisions.

Track and Report Metallurgical Performance - Conduct routine sampling, analysis, and metallurgical accounting. Maintain accurate records of metallurgical balances, recoveries, and plant efficiency metrics. Prepare internal reports and contribute to monthly technical summaries.

Collaborate Across Teams - Work with operations, maintenance, and geology teams to integrate metallurgical insights into daily decision-making. Provide input to capital projects, equipment selection, and commissioning activities.

Champion Safety and Compliance - Promote a strong safety culture and ensure that all metallurgical work aligns with environmental, health, and regulatory standards.

What You'll Bring

• 3–7 years of experience in mineral processing, ideally with exposure to both hydrometallurgical and flotation circuits.

• Strong understanding of heap leach dynamics, SX/EW systems, flotation chemistry, and comminution fundamentals.

• Skilled in metallurgical test design, data analysis, and performance optimization.

• Experience with metallurgical modeling and software tools such as METSIM, HSC, or similar process modeling software package

• Strong analytical and problem-solving capabilities.

• Excellent communication skills—able to translate technical findings into actionable recommendations.

• Proactive, safety-conscious, and results-driven, with a collaborative mindset.

• Ability to thrive in a field-based, production-focused environment.

Our culture is built on three principles:

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.