Lithium Hydroxide Production via Sorption and Membrane Purification
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Solution Overview
Problem
Current methods for producing lithium hydroxide from lithium-bearing brines face challenges such as high reagent consumption, large volumes of waste, and inefficiencies in concentrating lithium chloride solutions, particularly in brines with high calcium and magnesium content, leading to low processing rates and high impurity levels.
Innovation Solution
The method involves purifying the brine from solid-phase impurities before selective extraction using a granular sorbent, followed by nanofiltration, reverse osmosis, and deep ion-exchange purification to produce high-purity lithium hydroxide, with additional steps for reducing impurities and recycling sorbent materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If halurgic technology with stepwise separation of sodium and potassium chlorides is used to concentrate lithium-bearing brines, then lithium chloride concentration can be increased, but reagent consumption increases and large volumes of solid waste are formed
Solution Approach 1:
The patent extracts and removes solid-phase impurities from lithium-bearing brines using filtration before processing, separating harmful substances (solid impurities containing calcium, magnesium, and other contaminants) from the useful lithium-containing solution, thereby reducing subsequent reagent consumption and waste generation
Solution Approach 2:
The patent performs preliminary filtration to remove solid-phase impurities before the main processing steps of concentration and purification. This advance removal of contaminants prevents them from interfering with subsequent operations, reducing the need for additional chemical reagents and minimizing solid waste that would otherwise require disposal
2Manufacturing precision
If high concentration of lithium chloride solution is achieved through multiple filtration and concentration steps, then purity increases, but processing time and operational complexity increase
Solution Approach 1:
The patent combines multiple purification functions into a single integrated filtration system that simultaneously removes solid-phase impurities and prepares the solution for subsequent concentration steps. This consolidation reduces the number of separate operations and equipment units needed while maintaining high product purity
Solution Approach 2:
The patent segments the processing into distinct functional stages: initial filtration to remove solid impurities, followed by concentration, then purification. This segmentation allows each stage to be optimized independently, reducing overall complexity while achieving high purity lithium hydroxide through systematic progression
3Quantity of substance
If conventional electrolysis methods are used to produce lithium hydroxide from lithium chloride, then product can be obtained, but high impurity levels remain in the final product
Solution Approach 1:
The patent performs preliminary purification of the lithium chloride solution through filtration and concentration steps before electrolysis. This advance preparation removes impurities that would otherwise contaminate the lithium hydroxide product during electrolysis, ensuring high product purity without requiring complex post-electrolysis purification
Solution Approach 2:
The patent uses purified lithium chloride solution as an intermediary substance between the raw brine and the final lithium hydroxide product. This intermediate solution is carefully prepared through filtration and concentration to eliminate impurities, serving as a clean feedstock for electrolysis that ensures high product purity
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 reduces impurity content, increases processing efficiency, and allows for the production of high-purity lithium hydroxide and carbonate, while minimizing reagent consumption and operational costs, expanding the range of suitable raw sources and improving economic performance.
Implementation Method 1
selective extraction of LiCl from the original multicomponent lithium-bearing brine using granular sorbent DGAL-Cl
Implementation Method 2
nanofiltration for non-reactive purification from the bulk of impurities in the form of magnesium, calcium and sulfate ions
Implementation Method 3
reverse osmosis, and deep ion-exchange purification to produce high-purity lithium hydroxide
Implementation Method 4
deep ion-exchange purification from residual impurities
Implementation Method 5
electrolysis, which is carried out in an electrolysis cell with a Nafion cation-exchange membrane which separates the anolyte from the catholyte, where lithium ions are transferred to the cathode chamber, producing LiOH
Implementation Method 6
electrolysis cell with a Nafion cation-exchange membrane which separates the anolyte from the catholyte
Implementation Method 7
it is crystallized from catholyte solution in which the content of impure cations does not exceed 0.5%
Data Source
AI summary
A method for LiOHH2O production from lithium-bearing multicomponent hydromineral raw materials includes filtering lithium-bearing brine contaminated with suspended particles with regeneration of filters and processing of used regenerate, and obtaining pregnant lithium-bearing brine, isolation of lithium chloride from the brine in the form of a primary concentrate in sorption-desorption modules, and nanofiltration of the primary lithium concentrate from magnesium, calcium and sulfate ions. By means of reverse osmosis, electrodialysis concentration and ion-exchange purification from impurities followed by thermal concentration, the primary lithium concentrate is converted into a pregnant lithium chloride concentrate which is converted into a LiOH solution by membrane electrolysis. The LiOH solution is boiled down, resulting in LiOH.H2O crystallization.