Process Engineer

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.

• Act as the engineering owner of the SX and EW circuits, including mixer-settlers, organic and electrolyte handling, tank house, cell house and associated utilities.

• Monitor daily plant performance (PLS grade and flow, extraction and stripping efficiency, phase continuity, entrainment, current efficiency, cathode quality) and act on deviations.

• Define and maintain operating envelopes, control set points and alarm limits together with operations and control engineers.

• Lead technical troubleshooting of process upsets such as crud formation, organic degradation, impurity build-up (Fe, Mn, Cl, NO₃), short circuits and poor cathode morphology.

• Manage reagent strategy for extractant, diluent, smoothing agents and cobalt sulfate, including consumption tracking and supplier technical liaison.

• Produce daily, weekly and monthly process performance reports and metallurgical balances.

• Identify, evaluate and lead improvement projects that increase recovery, throughput, current efficiency and cathode grade, or reduce energy, reagent and operating costs.

• Use data analysis, mass and energy balances, and process modeling to quantify opportunities and build business cases.

• Plan and run plant trials and test work with the laboratory, vendors and external partners, then implement and verify results.

• Drive root-cause analysis on recurring losses and production incidents, and track corrective actions to closure.

• Support control-system optimization and the use of instrumentation and online analyzers.

• Provide process input to studies for capacity expansion, debottlenecking and new circuits, from concept through feasibility and detailed design.

• Develop and review process design criteria, PFDs, P&IDs, mass balances, equipment sizing and datasheets.

• Represent operations in design reviews, HAZOP and constructability workshops so new assets are operable and maintainable.

• Support pre-commissioning, commissioning and ramp-up of new or modified equipment.

• Contribute to cost estimates, schedules and risk assessments for capital projects.

• Apply process safety and management-of-change (MOC) practice to every process modification, with particular focus on fire risk in SX and acid mist in EW.

• Write and update SOPs, process descriptions and training material for operators.

• Coach operators, metallurgists and junior engineers, and share knowledge across teams.

• Support environmental compliance for effluents, emissions and organic losses.

• This role suits a hands-on hydrometallurgical/mechanical/chemical engineer who enjoys spending time in the plant, turning data into decisions, and seeing improvements through from idea to commissioning.

• 2+ years of process engineering experience in commissioning of chemical factories, mechanical equipment knowledge or project/design upgrades.

• Proven track record delivering process improvement projects with measurable results.