Characterization of rice husk ash obtained from an industrial source

Abstract

Chemical, physical and mineralogical characterization of an industrial rice husk ash is reported and the differences with ash typically obtained by laboratory combustion of husks were highlighted. Valorization of industrial ash was targeted by controlling the combustion temperature of rice husks at 600 °C, 650 °C, 700 °C and 750 °C in an atmospheric fluidized bed industrial boiler of a paper mill. The other parameters were ash sampling points (air-preheater, economizer and electrostatic-precipitator) and the ash processing condition (as-received and ground). Irrespective of the burning temperature or sampling point, all ashes had a cellular microstructure with a high specific surface area (25 m²/g − 50 m²/g), silica content was greater than 80% with the amorphous fraction being larger than 90%. Pozzolanic reactivity of ground ash for the entire burning temperature range of 600 °C -750 °C was acceptable and a 15% replacement of cement with the processed ash in blended mortars yielded optimum strength and flow performance.

Keywords:

• rice husk
• rice husk ash
• supplementary cementitious material
• pozzolanic reactivity
• compressive strength

Acknowledgments

Authors acknowledge the Department of Biotechnology, New Delhi, India, to provide a research grant under the aegis of DBT-Innovate, U.K. Newton-Bhabha Fund (BT/IN/Innovate-UK/35/BS/2016-17). We are grateful to our research partners M/s Kuantum Papers Ltd. Hoshiarpur, Punjab, India to provide kind support during the performance of experiments. Authors also express their gratitude to Prof. P.S. Mangat and Dr. Anthony Bell, Materials and Engineering Research Institute, Sheffield Hallam University, U.K., for their support in Rietveld analysis of the XRDs. The first author is grateful to the All India Council for Technical Education and Q.I.P. Centre, Indian Institute of Technology Roorkee, Roorkee, for providing a scholarship for his doctoral studies at the Indian Institute of Technology Roorkee, Roorkee, India. First author is also grateful to the Commonwealth Scholarship Commission, U.K. for providing scholarship to carry out his doctoral research at M.E.R.I., Sheffield Hallam University, U.K.

Disclosure statement

No potential conflict of interest.

Additional information

Funding

Authors acknowledge the Department of Biotechnology, New Delhi, India, to provide a research grant under the aegis of DBT-Innovate, U.K. Newton-Bhabha Fund (BT/IN/Innovate-UK/35/BS/2016-17)