Regular Article

Effects of mill scales on the combustion characteristics of pulverized coals

¹ School of Metallurgical Engineering, Anhui University of Technology, 243002 Ma'anshan, PR China
² Key Laboratory of Metallurgical Emission Reduction & Resources Recycling, Ministry of Education, Anhui University of Technology, 243002 Ma'anshan, PR China

^* Corresponding author: springcsu@126.com, dzx2012@ahut.edu.cn.

Received: 6 November 2016
Received in final form: 21 February 2017
Accepted: 5 July 2017

Abstract

The effects of mill scales on the combustion characteristics of pulverized coals, bituminous coal and anthracite are investigated by combustion experiments in a horizontal electric resistance furnace at 900 °C and by thermogravimetric analysis method. The performance of the process is estimated based on combustion rate, ignition temperature and burnout index. It is found that the combustion of pulverized coal can be enhanced by adding mill scales and the optimal addition content for bituminous coal and anthracite are 1% and 1.5%, respectively. With the mill scales addition, the combustion rates of bituminous coal and anthracite are increased by 21.31% and 7.53%, respectively. The results also show that the combustion reactivity of pulverized coals is also improved by mill scales addition. The ignition temperature and burnout index are decreased by 10 °C and increased by 8.03%, respectively, for the combustion of bituminous coal with 1% mill scales addition, and that are decreased by 3 °C and increased by 1.74% for the combustion of anthracite with 1.5% mill scales addition.