title: Effect of autoclaving and sintering on the formation of β-wollastonite.
abstract: β-wollastonite (β-CaSiO3) was synthesized from rice husk ash and calcium carbonate, and a study of the effects of the autoclaving and sintering steps is presented here. Autoclaving and sintering at 8h and 2h yielded the β-wollastonite phase in full, with improved crystallinity. Nucleation between rice husk ash and calcium oxide occurred around 135 °C, pressure 0.24 MPa, and growth proved to be more crystalline after the ripening period. For shorter processing times, and for both unsintered and unautoclaved samples, cristobalite and unstable tricalcium silicate phases were present. Crystallite size was increased by longer sintering times but reduced by longer autoclaving times. The β-wollastonite obtained had a random branch-like structure. In conclusion, the introduction of the autoclaving step successfully obtained β-wollastonite from a reaction between rice husk ash and calcium oxide.
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: hamisahismail@yahoo.com.
authors.forename: Hamisah
authors.initials: H
authors.lastname: Ismail
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: linda@ukm.edu.my.
authors.forename: Roslinda
authors.initials: R
authors.lastname: Shamsudin
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. Electronic address: azmi@ukm.edu.my.
authors.forename: Muhammad Azmi
authors.initials: MA
authors.lastname: Abdul Hamid
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D006358:Hot Temperature; D012275:Oryza; D010087:Oxides; D017640:Silicates / Q000737:chemistry*; D013242:Sterilization
chemical_list: D017610:Calcium Compounds; D010087:Oxides; D017640:Silicates; C016538:lime; C031293:calcium silicate
keywords: Autoclaving; Calcium oxide; Rice husk ash; Sintering; β-wollastonite