Aqueous Lithium Recovery Through Pre-Concentration And Direct Extraction

Solution Overview

Problem

Existing methods struggle to efficiently recover lithium from dilute aqueous sources, which are abundant but often overlooked, due to limitations in concentration and separation technologies, leading to inefficiencies and high costs.

Innovation Solution

A method involving a feed preparation stage to concentrate lithium sources using membrane separation and thermal evaporation, followed by direct lithium extraction through ion exchange or electrochemical separation, and subsequent purification and concentration stages to enhance lithium recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If direct lithium extraction is used on dilute brine sources, then lithium recovery can be achieved, but the process is inefficient and costly due to low lithium concentration

Engineering Contradiction:

Improvelithium concentrationVSAvoidlithium recovery efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies preliminary concentration of dilute brine using evaporation or membrane separation processes before feeding to the DLE unit. This preliminary action increases lithium concentration from dilute levels (e.g., <100 ppm) to levels suitable for efficient DLE operation, thereby resolving the contradiction between recovering lithium from dilute sources and maintaining high recovery efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the lithium recovery process into distinct stages: (1) brine concentration stage using evaporation or membrane separation, and (2) DLE stage for lithium extraction. This segmentation allows each stage to be optimized independently, with the concentration stage preparing the feed for efficient DLE operation, thus resolving the efficiency problem with dilute sources

Inventive Principle:

Principle #1Segmentation

2Quantity of substance

If conventional evaporation methods are used to concentrate brine, then lithium concentration increases, but energy consumption is high and other salts precipitate

Engineering Contradiction:

Improvelithium concentrationVSAvoidenergy consumption

Core Design Contradiction:

Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent changes the concentration parameter from direct thermal evaporation to controlled evaporation combined with membrane separation. This parameter change allows concentration to occur at lower energy input while maintaining selectivity for lithium, avoiding the high energy consumption and salt precipitation problems of conventional evaporation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces membrane separation as an intermediary process between the brine source and DLE. This intermediary selectively concentrates lithium while allowing other components to pass through or be retained differently, reducing the energy required compared to direct evaporation and preventing unwanted salt precipitation

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If membrane separation is used to concentrate lithium, then energy consumption decreases, but other salts may co-concentrate and interfere with extraction

Engineering Contradiction:

Improveenergy consumptionVSAvoidlithium purity

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent employs feedback control in the membrane separation process, monitoring the composition of the concentrate stream and adjusting operating parameters to maintain optimal lithium concentration while minimizing co-concentration of interfering salts. This feedback ensures high lithium purity for subsequent DLE operation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies local quality by using selective membrane materials with specific pore sizes and charge characteristics that preferentially allow lithium ions to pass while blocking or retaining other salt ions. This local selectivity at the membrane level achieves high lithium purity in the concentrate stream with low energy consumption

Inventive Principle:

Principle #3Local quality

4Device complexity

If lithium extraction is performed from dilute sources without pre-concentration, then process simplicity is maintained, but extraction efficiency and economics deteriorate

Engineering Contradiction:

Improveprocess complexityVSAvoidlithium recovery efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent applies preliminary concentration of dilute brine using evaporation or membrane separation processes before feeding to the DLE unit. This preliminary action increases lithium concentration from dilute levels (e.g., <100 ppm) to levels suitable for efficient DLE operation, thereby resolving the contradiction between recovering lithium from dilute sources and maintaining high recovery efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the lithium recovery process into distinct stages: (1) brine concentration stage using evaporation or membrane separation, and (2) DLE stage for lithium extraction. This segmentation allows each stage to be optimized independently, with the concentration stage preparing the feed for efficient DLE operation, thus resolving the efficiency problem with dilute sources

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively concentrates and recovers lithium from dilute sources, achieving high purity and yield, addressing the inefficiencies of current technologies and meeting growing demand for lithium.

Implementation Method 1

concentrating an aqueous lithium source in a feed preparation stage to yield an extraction feed having an extraction lithium concentration, using at least a membrane separation operation

Methodology Applied

Scientific EffectMembrane separation: Semipermeable Membrane

Implementation Method 2

extracting lithium from the extraction feed, or a derivative thereof, using direct lithium extraction in an extraction stage

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 3

extracting lithium from the extraction feed, or a derivative thereof, using direct lithium extraction in an extraction stage

Methodology Applied

Scientific EffectElectrochemical separation: Electrolysis

Data Source

PatentUS12447418B2Lithium recovery using aqueous sources

Publication Date: 2025.10.21 SCHLUMBERGER TECH CORP

AI summary

Described herein are methods of recovering lithium from dilute lithium sources. The methods include concentrating a dilute aqueous lithium source to yield an extraction feed having an extraction lithium concentration; extracting lithium from the extraction feed using direct lithium extraction in an extraction stage to yield a lithium intermediate; concentrating a stream obtained from the lithium intermediate in a concentration stage to yield a lithium concentrate; and converting lithium in the lithium concentrate to lithium hydroxide.