Systematic evaluation of amorphous silica production from rice husk ashes

Author(s)

Santana Costa, Jose Arnaldo ^[1] ; Paranhos, Caio Marcio ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, Polymer Lab, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF CLEANER PRODUCTION; v. 192, p. 688-697, AUG 10 2018.
• Web of Science Citations: 24

Abstract

Amorphous silica (SiO2) was extracted from the rice husk ashes (RHAs) of the agulhinha and cateto varieties. Optimized time, temperature, extractor concentration, and reaction time for a sustainable and cleaner production of SiO2 from RHAs were studied. Textural and internal structures were analyzed by N-2 adsorption-desorption isotherms. The percentage of SiO2 in the treated rice husks (RHs) increased by approximately 11 and 12% for the agulhinha and cateto varieties, respectively. The silica present in the RHAs remained predominantly amorphous for all of the times and temperatures investigated. The optimum parameters for calcination of the RHs were: 2 hat 700 degrees C. Type IV isotherms with type H1 hysteresis and good specific surface area values were observed. The optimum parameters for extraction of the amorphous silica were: concentration of 4 mol L-1 NaOH and 4 h of reaction. The extraction yield values were 80-99% and 83-97% for the agulhinha and cateto RHAs, respectively. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 14/05679-4 - Development of silica-based mesoporous materials from biomass for use as remediation system for polycyclic aromatic hydrocarbon (PAH's)
• Grantee: José Arnaldo Santana Costa
• Support type: Scholarships in Brazil - Doctorate