Optimization of potassium extraction from discontinuous evaporation brine using the Taguchi experimental design

Abstract

This study applies the Taguchi design of experiments (DOE) in optimizing the process of potassium extraction in discontinuous evaporation brine, particularly with regard to the evaporation temperature, initial K⁺ concentration, and evaporation time, which are the major factors in the process. An orthogonal array of L9 was used to reduce the number of experiments while maintaining statistical efficiency . The analysis of variance showed that evaporation temperature is the most significant factor, contributing approximately 72.5% of the total variation in Potassium Extraction Efficiency (PEE), followed by initial K⁺ concentration, which contributed 20.2%, and evaporation time, which contributed 5.6%. A predictive linear regression model was developed, and the results showed that all investigated factors positively influenced PEE within the studied experimental range, as confirmed by the R² value, which was greater than 98%. The optimal conditions were established to achieve the maximum PEE yield, and the results were: 90°C, 40 g/L of initial K⁺ concentration, and 6 hours of evaporation time. The optimized operating conditions established in this study provide a basis for future investigations on the integration of solar-assisted evaporation systems. These findings contribute to the valorization of desalination brine through improved potassium recovery.