Production of silica gel from waste metal silica residue

• Published in: Materials letters Vol. 275; p. 128125
• Main Authors: Morais de Oliveira, Andrielli, Alberto dos Reis Ferreira, Rondinele, César Martins Filho, Paulo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.09.2020; Elsevier BV
• Subjects: Cleaning; Differential scanning calorimetry; Extraction; Fourier transforms; Infrared analysis; Materials science; Metal silica residue; Residues; Silica gel; Silicon dioxide; Sol-gel processes; Thermal analysis; Thermogravimetric analysis; X ray fluorescence analysis; Yield; Extraction; Silica gel; Yield; Thermal analysis; Metal silica residue
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.128125

•The washing step of the silica gel was efficient, eliminating Cl particles as NaCl.•The percentages of SiO2 did not present significant differences (p < 0.05).•The methodology without HCl cleaning presented better results. Silica gel is a synthetic silica compound that can be extracted from metal silica residue by the sol–gel method. The aim of this research was the extraction of silica gel from silica metal residue presenting a methodology that optimizes the process of silica extraction and its future use in cement compounds. Extraction processes with and without HCl cleaning showed yields of 27 and 25% silica gel, respectively. This result was also confirmed in X-ray fluorescence and Fourier transform infrared spectroscopy analyzes. The thermogravimetric analysis and differential scanning calorimetry of the samples of silica gel with and without HCl cleaning in different atmospheres showed that in the oxygen atmosphere the process of mass loss occurred at lower temperatures.