Increasing the efficiency of silicon and aluminum extraction from Volclay by a water iteration treatment for the synthesis of MCM-41 nanomaterials

This work aims to reduce the prices of a wide range of nanomaterials which are unreachable in the industry by using natural sources as silicon and aluminum precursors. In a previous work, silicon and aluminum have been extracted from Volclay after applying the alkaline fusion process at 550 °C, and a water treatment of this fused clay by adopting a weight ratio (1:4, fusion mass:H₂O) to synthesize Al-MCM-41 nanomaterials. In this study, the weight ratio of fusion mass:H₂O was increased to 1:8 to synthesize a highly structurally ordered MCM-41 under the same reaction conditions. The Al-MCM-41 nanomaterials are investigated by inductively coupled plasma optical emission spectrometry (ICP–OES), powder X-ray diffraction (XRD), N₂ adsorption–desorption measurements and scanning electron microscopy (ESEM). As a result, the increase in the weight ratio fusion mass:H₂O generates more silica and aluminum, which allows the formation of well-ordered MCM-41 nanomaterials with high pore volume (0.70 cm³/g), high surface area (1044 m²/g), and uniform mesoporous diameter (3.67 nm); as a consequence, the increase in the weight ratio fusion mass:H₂O leads to an increase in the mass of Al-MCM-41 (9.3 g for 1:8 compared to 5 g for 1:4), whereas the yield of production of mesoporous materials increases to 86%.