Reducing impurities of silica sand by one step and two step leaching Available to Purchase

The demand of high purity quartz sand is increasing for various needs such as solar cells, semiconductor chips, optical fibers, catalytic chemicals, and flat panel displays. One of the most widely used processes for this purpose is the one step or two step leaching method. This study investigated purification process to increase the silica content of quartz sand using the one step leaching method using dilute hydrochloric acid and comparing to two step leaching using dilute hydrochloric acid and sodium bicarbonate as solvent. The effectiveness of the process of removing impurities from quartz sand was studied based on the results of analysis using XRF, XRD, and SEM-EDX. The results showed that two step leaching with dilute HCl and Na₂CO₃ was effective in reducing the level of impurities in quartz sand after the one step leaching using very low concentrations of hydrochloric acid. Dilute Na₂CO₃ can improve impurities removal. SiO₂ concentration increased from 96.3% in raw material to 98.3 and 98.8% after one-step and two-step leaching, respectively. Effectiveness of removing impurities increased from 54% by one step leaching method to 67.6% by two step leaching method.