Monovalent metal precipitation: experiments and simulations

CMI researchers from Idaho National Laboratory and OLI Systems conducted the activity for this highlight

Innovation       
Thermodynamic simulations accelerate development of precipitation methods for separation of monovalent metal ions (e.g., Li, Na, K) by enabling understanding of the key reaction mechanisms.

Achievement

  • The favored removal of Na+ compared to Li+ upon addition of CO2 to a synthetic brine solution was predicted by thermodynamic simulations that showed the lower solubility of NaHCO3 compared to Li2CO3.
  • Comparison of experimental observations and simulation predictions indicated that Li3PO4 precipitation is constrained by kinetics as well as thermodynamics.

Significance and Impact      
Thermodynamic modeling enables more efficient experimental efforts by constraining the design space, resulting in reduced costs and waste generation.

Hub Target Addressed  
Developing and applying scientific tools to accelerate technology maturation

 

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Separation of Na⁺ as Na2CO3 and NaHCO3 salts from Li⁺ and K⁺ was achieved through reaction with CO2. Experimental results are consistent with thermodynamic simulations, confirming that NaHCO3 formation is favored at lower CO2 supply.

  

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Comprehensive thermodynamic and experimental results indicate that Li3PO4 precipitation yield increases with higher initial Li concentrations and that the process is governed by both thermodynamics and kinetics.