Affiliation:
1. School of Chemistry and Materials Engineering, Liupanshui Normal University, Liupanshui 553004, China
2. School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221016, China
Abstract
Acid-leached gangue residue is produced after the gangue extraction of metal ions; the main component is silicon, which can be used to extract silica. To ascertain the kinetics and mechanism of silica extraction from acid-leached coal gangue residue, this study explored the effects of the NaOH concentration, solid-to-liquid ratio, reaction temperature, and reaction time on the extraction process. The optimized conditions, determined through this investigation, involved a NaOH concentration of 4 mol/L, a reaction time of 4 h, a solid-to-liquid ratio of 1:4, and a reaction temperature of 180 °C, yielding a SiO2 extraction ratio of 90.16%. Additionally, the leaching kinetics of silica in a NaOH solution were examined using three kinetic equations from the “unreacted shrinking core model”. The results revealed that the control type of the leaching process was the “mixing control”, and the apparent activation energy was determined to be 52.36 kJ/mol.
Funder
Guizhou Provincial Education Department
Guizhou Provincial Science and Technology Department
Liupanshui City Science and Technology Foundation