Effect of Extrusion on the Physical and Mechanical Properties of Briquette Made with Blast Furnace Flue Dust and Iron Ore Fines

In this study, the extrusion of reduced blast furnace composite fines at elevated temperatures allows manufacturing final products with distinctive microstructure and mechanical properties. The experimental results of extrusion of the composite powder under different laboratory conditions are presented and analysed. The main objective of the study is to demonstrate that blast furnace flue dust fines can be consolidated to highly dense products through extrusion. Reduced blast furnace flue dust and iron oxide fines were compacted at 100 MPa pressure to produce 20 mm and 40 mm diameter and height, respectively, and these compacted materials were subjected to different thermal treatment temperature, namely 1100 °C and 1200 °C, respectively. The product after heat treatment was extruded by direct extrusion process at different pressures such as 175 MPa and 240 MPa, respectively, at both the temperatures. The mechanical properties such as density, compressive strength, hardness and microstructure of the final product have been reported. Quantitative and qualitative metallography has been applied within the extruded product to match with the values of the mechanical properties. The product achieves maximum density of 7.55 gm/cc after extrusion with 240 MPa extrusion pressure at 1200 °C. Furthermore, the maximum compressive strength and hardness values are 336.67 MPa and 117.42HV20, respectively, when the extrusion pressure was maintained at 240 MPa and heat treated at 1200 °C.