Process Metallurgist

Position Summary The Process Engineer / Process Metallurgist designs, executes, and reports client-funded chemical and metallurgical process testwork programs across a range of commodities, chemical and industrial mineral products, and flow sheets, and works alongside McCarl's Technical Services engineering group to carry that testwork forward into process and plant design. This role spans the full scale-up path - bench testwork, continuous pilot and demonstration plant campaigns, and the engineering that carries that data into full-size commercial plant design.

It generates the process data that anchors flow sheets, mass/energy/water balances, and cost estimates, and carries a substantial process design scope: design criteria, process flow diagrams, equipment sizing and specification, reagent and utility consumption, vendor evaluation, and support through commissioning and performance verification.

Key Responsibilities Develop and manage bench, pilot, and demonstration-scale testwork scopes, budgets, and schedules for gold, base metals, tungsten, rare earths, lithium, critical minerals, industrial minerals, and chemical process projects.

Execute and supervise testwork across metallurgical and chemical unit operations: comminution, gravity, flotation, leaching (cyanidation/CIL, acid, POX, bio-oxidation), solvent extraction and ion exchange, precipitation and crystallization, evaporation, roasting/calcination, drying, and solid-liquid separation.

Design test matrices, interpret results, and translate data into flowsheet recommendations and preliminary mass, energy, and water balances.

Plan, build, and run continuous pilot and demonstration plant campaigns - equipment selection and rental, layout, instrumentation and sampling plans, shift coverage, reagent and feed logistics, and on-site or vendor-facility supervision.

Reconcile pilot and demonstration plant data: surveys, mass balance closure, locked-cycle and steady-state validation, and generation of the design basis and vendor guarantee data required for full-size plant design.

Own scale-up from bench through pilot and demonstration to full-scale commercial plants - scale-up criteria and factors, residence time and geometric similitude, materials of construction, recycle and water balance effects, and impurity deportment over continuous operation.

Collaborate with McCarl's Technical Services engineering clients and staff on process design, plant design, process modeling and simulation, and equipment sizing that build directly on bench and pilot results.

Develop process design deliverables: design criteria, block flow and process flow diagrams (PFDs), equipment lists, mass/energy balances, hydraulic and reagent/utility consumption calculations, and process control philosophies.

Size and specify major process and chemical equipment - mills, thickeners, filters, reactors, tanks, heat exchangers, pumps, evaporators, dryers, and kilns - and support P&t with the engineering group.

Prepare equipment datasheets and technical bid packages, evaluate vendor proposals, and support factory and site acceptance testing.

Build and maintain steady-state process models and simulations to support scale-up, debottlenecking, trade-off studies, and plant optimization.

Support commissioning, start-up, and plant performance troubleshooting; participate in HAZOP and design reviews with a safety-in-design mindset.

Provide the process and metallurgical basis and bench/pilot testwork inputs for Class 5 through Class 3 estimates, PEA, PFS/DFS, and FEED-level studies; own scale-up assumptions, design criteria, and detailed design support through construction and start-up.

Author clear, defensible client test reports and technical memoranda; present findings to clients and study teams.

Coordinate sample prep, assaying, and mineralogy (QEMSCAN/MLA) with internal and external labs; ensure QA/QC integrity.

Maintain laboratory and pilot plant safety, data management, and chain-of-custody standards.

Support proposal development and client business development as a technical resource.

Qualifications Required for all candidates:

B.S. in Chemical, Metallurgical/Mineral Processing, or a closely related engineering discipline. Hands-on chemical or metallurgical process testwork experience in a commercial lab, operating plant, or consultancy - from roughly 1 year for early-career candidates through 10+ years for senior hires.

Working knowledge of chemical and metallurgical unit operations across at least two commodity or product groups; flotation, hydrometallurgy, and chemical processing strengths valued.

Strong data analysis, technical writing, and client communication skills.

Comfortable in a fast-paced, multi-project environment with competing deadlines.

A track record of leading testwork programs end to end and owning client relationships.

Experience designing, operating, or supervising continuous pilot or demonstration plant campaigns, including data reconciliation and mass balance closure.

Familiarity with…