Critical Mineral Recovery & Material Recovery
Systems Engineering
We support technology developers turning lab chemistry and mining systems into reliable, field-ready hardware.
Johnston Engineering designs, analyzes, prototypes, builds, and test pilot-scale and demo-scale systems that recover lithium, nickel, cobalt, rare earths, phosphorus, and other critical materials from brines, black mass, tailings, red mud, and industrial process streams.
Our work reduces technical risk so your team can move forward with confidence.
Process Translation
We design and size solvent extraction columns, pumps, piping, manifolds, support structures, heat exchangers, and remaining system components based on your operating conditions, flow rates, chemistry and process requirements.
Pilot-Ready Deployment
We deliver ready to operate systems. We integrate proper drains, vents, sampling ports, controls, instrumentation locations, and serviceability features ready for field deployment.
Harsh Materials Handling
Handle acids, bases, chlorides, and abrasive slurries with confidence. We design equipment to protect operators and extend system life by selecting appropriate materials, seals, and safeguards for aggressive chemistry and wear.
Unit Operations We Support
Electrochemical - Our electrochemical work includes electrowinning and electrorefining skids for metal recovery, electrodialysis systems (ED/BMED, EDI, CDI/MCDI) for selective separation, and development platforms for electro-oxidation and electrocoagulation processes.
design electrolyzers from scratch and we can design skids that support electrochemical process for the above ^ processes.
Membrane & Solid/Liquid Separation - We design systems that support membrane separation technologies and
membrane contactors. Our team integrates your custom system with off-the-shelf (OTS) and custom solid/liquid separation equipment such as
filter presses,
centrifuges, and
hydrocyclones for reliable, continuous operation.
Hydrometallurgy - Our hydrometallurgical work includes
ion exchange (IX) columns for adsorption and desorption,
solvent extraction (SX) systems, and complete
SX-EW flowsheets. We also design
selective precipitation
and
crystallization systems and leaching equipment with integrated
PLS handling and
raffinate management.
Our team brings deep experience in electrochemical, membrane, and hydrometallurgical system design to help clients move from process concept to working hardware.
Engineering That Reduces Scale-Up Risk
Scaling a recovery process isn’t just about chemistry - it’s about building systems that operate reliably with aggressive fluids, abrasive slurries, and ever-changing feed streams. Our team bridges the gap between process design and mechanical reality, helping you build equipment that’s safe, maintainable, and ready for deployment..
Structural & Mechanical Integrity
Johnston Engineering performs
Structural Finite Element Analysis (FEA)
for pressure boundaries, vessel supports, frames, and test stands. We assess deflection, vibration, and stress under operating loads and thermal expansion. Our designs conform to sound engineering practices and relevant standards such as ASME and B31.3 where applicable, ensuring both safety and reliability for pressurized or corrosive systems.
Thermal Analysis
Our engineers use
ANSYS
and analytical modeling to evaluate heat generation, dissipation, and transfer across packed beds, reactors, and electrochemical cells. We design heat exchangers, cooling jackets, and insulation strategies to maintain precise thermal control for endothermic and exothermic processes. We also specialize in managing heat from high-current electrochemical systems and scaling up laboratory temperature control systems to pilot or industrial environments.
Chemical Compatibility & Materials Selection
We are experienced in designing systems that handle
acids, bases, and aggressive solutions
such as HCl, H₂SO₄, NaOH, and ammonia. Our team selects wetted materials, gaskets, and fasteners for optimal corrosion resistance, utilizing PVDF, PTFE, PFA, ETFE, FRP, CPVC, and Hastelloy where appropriate. All fluid-contact components are specified for chemical duty, minimizing maintenance and maximizing equipment life.
Deploy Your Material Recovery System
We help teams go from process concept to working pilot hardware. Share your process flowsheet and scaling goals.