Cements from rice hull ash I: Synthesis variables

ENVR 158

Flávio A. Rodrigues, flavioar@umc.br, Cenro Interdisciplinar de Investiagação Bioquímica (CIIB), Universidade de Mogi das Cruzes, Rua Cândido Xavier de Almeida Souza 200, Mogi das Cruzes SP, 08780-210, Brazil and Jonatas Silva Romano, jonatasromano@yahoo.com.br, Centro Interdisciplinar de Investigação Bioquímica (CIIB), Universidade de Mogi das Cruzes (UMC), Av. Dr. Cândido X. A. Souza 200, Mogi das Cruzes, 08780-911, Brazil.
Rice hull contains about 20% silica. Usually this material is burned at rice fields rendering silica particles that cause environmental problems. On the other hand, commercial Portland cement is a complex material; however, two calcium silicates are the most important components: Ca3SiO5 and beta-Ca2SiO4. This work describes the synthesis of beta-Ca2SiO4 using silica obtained from rice hull. Rice hull was burned at 600°C to remove the organic material. The solid reactants (silica, calcium oxide and barium chloride) were weighed and water was added in order to render suspensions having a solid:water ratio of 1:20. The suspensions were treated in an ultrasonic bath for 60 minutes. After drying, the resulting solids were grounded and heated up to 800°C. The effect of particle size was studied using FTIR spectroscopy, x-ray diffraction and differential thermal analysis. It was found that particle size determines the extension of the reaction and energy consumption.
 

General Papers
6:00 PM-8:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Environmental Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006