Synthesis of mesoporous silica MCM-41 using sodium silicate derived from copper ore tailings with an alkaline molted-salt method

The alkaline molten-salt method was taken to effectively extract silicon from the copper ore tailings at 500-600 degrees C. The extraction rate of SiO2 and Fe2O3 was ca. 82% and below 2%, respectively. Hematite was not converted to soluble NaFeO2 in low temperature NaOH-NaNO3 molten system. Mesoporous MCM-41 was synthesized using a hydrothermal method with the extracted Na2SiO3. The analysis of small angle XRD, N-2 adsorption-desorption and HRTEM showed that the silica sample had a regular hexagonal structure of typical mesoporous MCM-41. The obtained MCM-41 silica had a BET specific surface area of 946.68 m(2)/g and mesopore volume of 0.76 cm(3)/g. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.