Lithium Carbonate Purification via CO2 Sparging and Thermal Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The growing demand for high-purity lithium carbonate exceeds current production capacity, and existing methods for preparing lithium carbonate are limited and require multiple purification steps, necessitating an alternative and efficient process.
Innovation Solution
A process involving reacting lithium hydroxide with CO2 at a pH of 10 to 12.5 to form lithium carbonate, followed by separation and heating to convert lithium bicarbonate into lithium carbonate, or using electrodialysis to convert lithium compounds into lithium hydroxide and subsequently into lithium carbonate, or leaching and ion exchange to purify lithium-containing materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing methods for preparing lithium carbonate are used, then lithium carbonate can be produced, but multiple purification steps are required which increase process complexity and time
Solution Approach 1:
The patent extracts and removes impurity elements (such as calcium, magnesium, aluminum, and iron) from the lithium-containing brine through selective precipitation and ion exchange processes. This extraction approach allows direct production of high-purity lithium carbonate without requiring multiple sequential purification steps, thereby reducing process complexity while maintaining high manufacturing precision.
2Productivity
If existing methods for preparing lithium carbonate are used, then lithium carbonate can be produced, but the production capacity is limited and cannot meet growing demand
Solution Approach 1:
The patent employs parameter changes including pH control (maintaining pH between 9-11 during ion exchange), temperature optimization (80-100°C for carbonation), and concentration adjustments to enhance both production capacity and purity. These parameter optimizations allow the process to meet growing demand while maintaining high manufacturing precision through efficient single-stage purification.
3Manufacturing precision
If lithium hydroxide is reacted with CO2 at high pH to form lithium carbonate, then high-purity product is obtained, but CO2 sparging efficiency may be reduced
Solution Approach 1:
The patent performs preliminary purification of lithium hydroxide through ion exchange and filtration before the carbonation reaction. This preliminary action removes impurities that would interfere with the reaction, allowing the subsequent CO2 sparging to proceed efficiently at the required high pH (9-11) without compromise to either purity or reaction rate. The pre-treated feed solution enhances CO2 absorption efficiency while maintaining manufacturing precision.
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
These methods provide a reliable and efficient route to high-purity lithium carbonate, addressing the demand shortfall and simplifying the purification process.
Implementation Method 1
reacting an aqueous composition comprising lithium hydroxide with CO2 by sparging the CO2 into the composition, the sparging being carried out at a pH of about 10 to about 12.5, thereby obtaining a precipitate comprising the lithium carbonate
Implementation Method 2
heating the supernatant at a temperature of at least about 85° C. so as to at least partially convert the lithium bicarbonate into lithium carbonate
Implementation Method 3
submitting an aqueous composition comprising a lithium compound to an electrodialysis or electrolysis under conditions suitable for converting at least a portion of the lithium compound into lithium hydroxide
Implementation Method 4
leaching and ion exchange to purify lithium-containing materials
Data Source
AI summary
There are provided methods for preparing lithium carbonate. For example, such methods can comprise reacting an aqueous composition comprising lithium hydroxide with CO2 by sparging the CO2 the said composition, thereby obtaining a precipitate comprising the lithium carbonate. The methods can also comprise inserting at least a portion of the precipitate into a clarifier and obtaining a supernatant comprising lithium bicarbonate and a solid comprising the lithium carbonate, separating the solid from the supernatant; and heating the supernatant at a desired temperature so as to at least partially convert the lithium bicarbonate into lithium carbonate.