Danfoss solutions for brine mining

Brine mining, also referred to as brine valorization, is the process of extracting valuable minerals and salts from highly saline water sources. These sources include geothermal fluids, inland salt lakes, oil and gas wastewater, seawater, SWRO brine reject, and industrial effluents.

Instead of physically mining solid ores, brine mining is a process of separating water from dissolved minerals, often through multiple concentration staages. Once the brine is sufficiently concentrated, specific minerals like lithium, potassium, magnesium, or salts can be selectively recovered.

Watch Amogh Sharma answering the question: “What is brine mining (also called brine valorization)?”

Brine mining enables the extraction of a variety of minerals, including:

• Lithium, critical for battery production
• Potassium and magnesium, used in agriculture and industry
• Bromine, used in flame retardants and pharmaceuticals
• Sodium chloride in the form of industrial or food-grade salts
• Other trace elements like boron, rubidium, and cesium

Brine mining generally follows this process chain:

• Extraction: Brine is pumped from subsurface reservoirs, geothermal wells, seawater, or captured as an industrial byproduct
• Pre-treatment: Solids, organics, or scale-forming compounds are removed to protect downstream equipment
• Pre-concentration: This reduces water content to increase mineral concentrations; technologies include membrane-based and thermal processes
• Final concentration and recovery: Typically involves thermal technologies like evaporators and crystallizers, where solids are precipitated and extracted
• Post-treatment: Includes handling of residual brine or waste, water reuse, or reinjection

Watch Georg Herborg answering the question: “What are the main stages in the brine mining process?”

Brine mining depends on both membrane and thermal pre-concentration technologies:

Membrane:

• Reverse osmosis (RO)
• Osmotic-assisted RO (OARO)
• Nanofiltration (NF)
• Forward osmosis (FO)

Membrane-based technologies are more energy-efficient than thermal and are well-suited for reducing water volume before thermal processing.

Thermal:

• Multi-effect distillation (MED)
• Mechanical e(MVC)
• Vacuum Evaporation

More energy-intensive, thermal-based technologies are effective at higher concentrations.

Danfoss provides a modular, high-efficiency platform of components tailored to the unique demands of high-pressure membrane processes in brine mining – particularly in pre-concentration stages using technologies like reverse osmosis (RO) and osmotic-assisted RO (OARO).

Our core technologies comprise:

• APP high-pressure pumps
  Danfoss APP axial piston pumps are positive displacement pumps designed for consistent high efficiency across a wide operating range. Unlike centrifugal pumps, which lose efficiency when operating away from their best efficiency point, APP pumps maintain over 91% efficiency even as pressure and flow requirements change. This makes them ideal for brine mining systems using both SWRO and OARO pre-concentration, where operating conditions can vary from stage to stage. Operators can adjust flow and pressure with no efficiency penalty. The result is a single, flexible pump platform that simplifies system design and maximizes energy savings.
• iSave and MPE70 ERDs
  The iSave and MPE70 isobaric energy recovery devices go beyond pressure recovery. In addition to reducing pump load and energy use with outstanding efficiency, they also provide active control over pressure and mixing, a key advantage in processes like OARO, where controlled brine blending lowers osmotic pressure and improves membrane performance. Unlike passive ERDs, active ERDs integrate pressure exchangers and booster pump for real-time process control. Proven at Hyrec’s brine mining plant in Indonesia, where iSave ERDs operate at over 93% efficiency while reducing energy consumption, extending membrane life, and stabilizing system performance under fluctuating conditions.

Together, Danfoss APP pumps and active ERDs form a flexible, energy-efficient platform for membrane-driven brine concentration systems. They support higher recovery rates, greater system uptime, and improved environmental performance – all of which are essential as the industry moves toward more sustainable, scalable brine mining solutions.

Additionally, Danfoss provides application and co-innovation support, working closely with plant designers and system integrators to optimize performance and adapt to specific brine chemistries. Danfoss solutions are found in several pilot and commercial installations, including the Hyrec brine mining plant in Indonesia for the production of food-grade salt.

Brine mining comes with a unique set of technical, economic, and environmental challenges:

• Energy consumption: Concentrating brine, especially in thermal stages, is energy-intensive. Membrane rather than thermal pre-concentration can reduce total energy use
• Operating costs: Energy, chemicals, and maintenance costs must be tightly managed
• CO₂ footprint: Projects relying fully on thermal methods tend to have higher emissions unless powered by renewables
• Brine variability: The composition of brine sources varies widely, requiring customized process design
• Scaling and fouling: Minerals can precipitate inside equipment, reducing efficiency and increasing downtime
• Waste brine and discharge: Must be treated or managed carefully to minimize environmental harm

Yes, brine mining is increasingly viable, not least for minerals like lithium, where global demand is rising rapidly, but also for the production of food-grade salt at scale as well as potassium, magnesium, and bromine. Key factors influencing the business case include:

• Mineral market prices
• Concentration levels in brine
• Technology mix (membrane vs thermal)
• Energy costs and availability
• Plant reliability and scalability

Yes, this is a developing area of interest. SWRO reject brine, the concentrated waste stream from seawater desalination, contains valuable elements like lithium, magnesium, and boron.

While currently underutilized, several pilot projects are exploring the valorization of SWRO reject as a secondary mineral resource. As desalination expands globally, so too does the potential to turn this waste stream into a feedstock for low-impact brine mining.

Brine mining is a rapidly growing segment of the mineral extraction industry, driven by:

• Surging demand for battery minerals, especially lithium
• Global interest in mining alternatives with lower environmental impact
• Expansion of ZLD regulations, especially in water-stressed regions
• Technological advances in high-pressure membrane systems, automation, and system integration, that reduce total cost of ownership (TCO)
• Greater availability of industrial brines from geothermal, oil and gas, and desalination