Regular Article

Evolutional behavior of carbonaceous material during dissolution in molten iron of COREX

¹ State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, 430081, PR China
² School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China
³ State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing, 100083, PR China

^* e-mail: xu_runsheng@163.com

Received: 11 September 2017
Accepted: 9 February 2018

Abstract

The dissolution behaviours of lumpy coal and coke used in COREX gasifier in molten iron were investigated. The time-dependent interfacial reaction products were observed and the microcrystalline structures of solid fuels were identified. The results showed that the rate of carbon dissolution in molten iron using lumpy coal was significantly less than that when the coke was used. The ordered carbon microcrystalline at the reaction interface would be a priority to dissolve. The interface thickness of the eroded coke was larger than that of coal char due to the uneven microtexture distribution and the irregular pore structure. The amount of attachments on the erosion interface was positively related to the dissolution time regardless of the type of solid fuel. Although the amount of ash phases on the coal char surface was less than that on the coke surface, the final carbon content in molten iron and dissolution rate of coal char were still less due to its microstructure of carbon matrix. This study contributes to understanding the dissolution mechanism of the solid fuels used in COREX gasifier and improving the fuel utilization.