Waste Epoxy Modified Iron Oxide-Polymer Composite Pellets: Green Strength Development and Oxide Reactivity in Ironmaking Technology

Abstract

The effect of waste epoxy blending with iron oxide-polymer composite pellets on mechanical compressive strength (crushing strength), nature of crushed pellets and extent of reduction of iron oxide in iron oxide-polymer composite pellet has been investigated in the laboratory. The mechanical compressive strength (crushing strength) of self-reduced pellets modified with and without waste epoxy was determined using a universal mechanical test equipment INSTRON 3369 operating at load cell 50 KN and crosshead speed 2mm/min. Gas analysis of the offgas was conducted on thermal decomposition products at 1600 °C using a continuous infrared gas analyser, followed by reduction studies at 1200 and 1600 °C. It was observed that incorporating waste epoxy into the green pellets results in significant improvement in the crushing strength from around 0.2 kN to over 4.0 kN. Additionally, green pellets with waste epoxy did not suffer from catastrophic pulverisation that was observed for pellets without epoxy. Gas measurements by continuous infrared gas analyser revealed significant amounts of the gaseous reducing agents CO and CH₄ and minor amounts of CO₂ as the major gaseous products from thermal decomposition at 1600 °C. Finally, the presence of waste epoxy in the pellet resulted in significant improvement in the extent of reduction of Fe₂O₃ by raw palm nut shell (PNS) and charred palm nut shell (CPNS), with measured extent of reduction increasing from 43.6% to 92.7% and from 63.3% to 96.9% at 35% replacement of PNS and CPS, respectively.

Keywords: Waste Epoxy, Palm Nut Shells, Composite Pellets, Compressive Strength, Extent of Reduction