Impurity removal from Si by Si-Ca-Mg ternary alloying-leaching system

In this work, Si-Ca-Mg alloys were made with different compositions and solidification conditions to investigate the impurity segregation separation performance from Si, especially for crucial P at several ppmw levels. Varying acid leaching parameters also employed optimized process window. Results indicate that novel alloying-leaching system is valid high extraction. The ternary intermetallic phase Ca7Mg7.5±?Si14 appears as main precipitate in all gather other minor impurities. Rapid cooling significantly reduced size of precipitates Si grain, was limited. experiments, HCl found most economical agents among studied combinations. Smaller particle promotes efficiency, but increment narrows increasing Ca/Mg ratio. Leaching kinetics following modified Kröger-Ziegler model based on a cracking-shrinking mechanism. purification efficiency increases mixing ratio, by rapid cooling. An analytical developed alloy predict its removal varying concentration through thermodynamic approach, which shows good agreements experimental results.