Industrial post-DLE treatment and lithium recovery systems
Lenntech designs and delivers industrial post-DLE brine treatment and lithium recovery systems for downstream processing of Direct Lithium Extraction (DLE) streams.
Lenntech systems are implemented as complete installations down- or side-stream of DLE units, focusing on polishing, conditioning, and selective separation or recovery of lithium from high-salinity process streams.
These systems are typically integrated in two configurations:
- Post-DLE polishing and separation of lithium-bearing product streams
- Recovery of residual lithium from spent brine, membrane concentrates or other side streams
Lenntech delivers engineered systems including concept validation, process design, equipment supply, installation, and commissioning, specifically adapted to high-TDS environments and complex brine chemistries.
Application context
In a DLE process, lithium is first extracted from raw brine using upstream technologies such as adsorption, sorption, membrane separation, or solvent-based extraction. Depending on the DLE configuration, lithium would be present:
- In the DLE product stream requiring further polishing and separation
- In a spent brine, membrane concentrate or other side streams from which remaining lithium can still be recovered
These streams are typically clarified but may still contain:
- High total dissolved solids (TDS)
- Multivalent ions contributing to hardness
- Residual contaminants impacting separation efficiency
- Complex salt matrices requiring selective fractionation
Post-DLE treatment systems or lithium recovery units are therefore required to stabilize these streams and enable efficient lithium separation or recovery.
Lenntech provides dedicated post-DLE treatment systems to address these challenges and optimize lithium recovery performance.
Typical Lenntech solution
A typical Lenntech post-DLE brine treatment or lithium recovery system consists of a combination of filtration, ion exchange, and membrane separation technologies, engineered according to the characteristics of the DLE output stream and the targeted lithium recovery strategy.
1. Brine conditioning and filtration- Multimedia filtration (MMF), ultrafiltration (UF) or equivalent
- Removal of suspended solids and residual fouling components
- Protection of downstream Lenntech membrane and ion exchange systems
Illustration of a multimedia filtration unit
- Conditioning steps to stabilize water chemistry prior to membrane separation
- Optimization of brine composition for selective lithium separation
- Ion exchange systems for hardness reduction and removal of interfering ions
Illustration of an ion-exchange unit
Lenntech integrates advanced membrane systems, including:
- Nanofiltration (NF)
- Reverse osmosis (RO)
- Closed-circuit reverse osmosis (CCRO)
- High-pressure or ultra-high-pressure RO (UHPRO)
- Ultra-high-pressure nanofiltration (UHPNF)
Illustration of a Reverse Osmosis unit
These systems enable:
- Controlled separation and recovery depending on process objectives
- Selective concentration of lithium relative to competing ions
System design is adapted depending on whether treatment targets the lithium product stream or the recovery of lithium from the spent brine or other side streams from the DLE unit.
Process Flow Diagram
A typical Lenntech post-DLE brine treatment or lithium recovery system is illustrated below:
Both post-DLE product stream and residual lithium stream treatment systems may incorporate similar process technologies. However, they are designed to operate under different conditions (such as different flow rates, pressures, and temperatures), reflecting the lower lithium concentration present in the side streams and varying concentrations in other compounds.
Treatment of spent brines and side streams aims to recover remaining lithium before discharge, reinjection, or reuse, contributing to increased overall lithium recovery from the DLE process.
Example system configuration
Typical Lenntech implementation (representative configuration):
- Flow rate: 30 m3/h
- Feed water:
- Concentrated brine from post-DLE process using membrane separation
- ~ 2g/L lithium – traces of aluminum – hardness up to 5000 ppm CaCO3
- Technologies applied:
- Ion exchange (aluminum and partial hardness reduction)
- Stream dilution
- Membrane separation (NF) operating at 10-15 bars
- Goal:
- Lithium and water recovery – recovered lithium product stream to be reinjected into post-DLE process
- Integration point:
- Concentrate line on existing DLE extraction process before discharge
For this specific project, Lenntech first carried out a feasibility study to identify the most suitable process chains for brine pretreatment and subsequent lithium recovery. The study included laboratory testing to evaluate different technology options and to define key operating parameters.
Lenntech has extensive experience in high-salinity water treatment, membrane system design, and selective ion removal, which are directly applicable to post-DLE lithium processing.
Applications of treated streams
Lenntech post-DLE treatment systems enable:
- Polishing and stabilization of lithium product streams
- Additional lithium recovery from spent brines or membrane concentrates
- Reduction of fouling and scaling in downstream processes
- Improved overall lithium recovery efficiency from DLE installations
- Controlled management of recycle, discharge, or reinjection streams
Lenntech systems are designed to optimize overall lithium recovery and process efficiency within integrated DLE operations.
Lenntech scope of supply
Lenntech delivers complete post-DLE treatment systems and installations, including:
- Process assessment and technology selection
- Laboratory testing, pilot testing, and performance validation
- Detailed engineering
- Filtration, ion exchange, and membrane equipment supply
- Modular or skid-mounted system construction
- Installation supervision and commissioning
Lenntech acts as a system integrator for post-DLE treatment, ensuring seamless integration with upstream DLE technologies and downstream processing steps.
Optional configurations and flexibility
Depending on DLE configuration and recovery objectives, Lenntech post-DLE systems may include:
- Single-stage or multi-stage membrane arrangements
- Alternative membrane types and operating pressures
- Partial recycle or bleed concepts
- Modular systems for pilot or early-phase projects
System configurations are tailored by Lenntech based on brine composition, recovery targets, and integration constraints.
Why choose Lenntech for post-DLE systems
Lenntech combines technical expertise and system integration capabilities that make it well suited for post-DLE lithium brine treatment:
- Proven experience in high-salinity and complex water treatment systems
- Strong capabilities in membrane and ion exchange process design
- Extensive background in industrial process water and brine treatment applications
- Ability to deliver custom-engineered systems adapted to specific DLE technologies
- Flexible approach covering pilot, modular, and full-scale installations
Lenntech supports clients from process evaluation through to full system implementation, ensuring reliable and optimized post-DLE performance.
For more information or quotation, please contact us: 
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