Extraction Of Silicon Oxide From The Partially Dealuminated Metakaolin Residue Of The Kaolin-based Aluminum Sulfate Manufacturing Process

Gamal Aboulfotouh, Aluminum Sulphate Co. of EgyptFollow
Nabil Abdullah Al-Sagheer, Aluminum Sulphate Co. of EgyptFollow
Noura Fathy Abdel Salam, Faculty of Engineering, Cairo universityFollow
Fayza S. Hashem, Faculty of science, Ain Shams university, Cairo, EgyptFollow

Article Type

Research Paper

Corresponding Author

Nabil Abdullah Al-Sagheer

Highlights

Partially dealuminated kaolin residue (PDK) of kaolin-based aluminum sulfate coagulant can be utilized for the extraction of silica and production of sodium.
The leachability of silica was improved by the reduction of Al, Fe, and Ti concentrations. About 90 % of silica was recovered from the digestion of partial dealuminated kaolin with a 5-molar solution of NaOH with a ratio of 1: 5 for 2 hours at 75°C. 98.4% of silica was extracted at the neutral pH.
The produced sodium silicate was treated with amorphous silica to raise the modulus of sodium silicate.

Abstract

Partially dealuminated metakaolin (PDMK) is a by-product of aluminum sulfate production. The novelty is to use PDMK as a low-cost source for extraction of silica and production of high modulus Na₂Si₂O₃ at relatively low temperature and at normal pressure. The process of silicon oxide extraction was tested, including the thermodynamic parameters such as the heat of formation, the entropy, and the enthalpy of the reactions. The PDMK and the formed compounds were characterized using a Fourier transform infra-red spectrophotometer (FTIR), and X-ray diffractometry (XRD). The effect of the dissolved aluminate compound on the extraction procedure of the amorphous silicate was also tested. 50%, 45%, and 18%, of Al, Fe, and Ti elements were removed respectively to improve the extraction of silica. 88.7% of silica was extracted by using NaOH (5 Mol.), at 75°C for 2h. A sodium silicate of modulus (SiO₂: Na₂O) 1.1 was prepared as indicated in the above figure. A low silica modulus sodium silicate (1.1) was used to prepare high silica modulus sodium silicate with SiO₂: Na₂O = 3.11 at 80°C for 3h. At 200 °C and for 3h of alkaline digestion reaction, the ratio of SiO₂ to Na₂O reached 3.55.

Keywords

Amorphous silica, kaolin-based aluminum sulfate residue, partial dealuminated metakaolin, silica gel, silica preparation, sodium silicate synthesis

Recommended Citation

Aboulfotouh, Gamal; Al-Sagheer, Nabil Abdullah; Abdel Salam, Noura Fathy; and Hashem, Fayza S. (2024) "Extraction Of Silicon Oxide From The Partially Dealuminated Metakaolin Residue Of The Kaolin-based Aluminum Sulfate Manufacturing Process," Egyptian Journal of Petroleum: Vol. 33 : Iss. 4 , Article 4.
Available at: https://doi.org/10.62593/2090-2468.1051