Development and characterization of epoxy- based composites filled with Linz-Donawitz sludge

Integrated steel plants in general produce large amounts of solid wastes during iron and steel making process. LD sludge or Linz-Donawitz sludge (LDS) are the fine solid particles recovered after wet cleaning of the gas emerging from LD convertors during steel making. In general 8 kg Linz-Donawitz sludge is generated per one ton of crude steel production. This solid waste can have many valuable product-oriented applications if processed economically. The common reuse methods for Linz-Donawitz sludge are recovery of metal values, recycling in sinter plant, and production of value-added products. But its use as filler in polymer composites is not yet established. This work includes the processing and characterization study of epoxy resin filled with micro-sized Linz-Donawitz sludge. Mechanical properties of the composites are evaluated under standard test conditions. Sliding wear tests are conducted using Taguchi's L25 orthogonal arrays over a range of sliding velocities (36-315 cm/s), normal loads (5-25 N), sliding distances (500-2500 m), and LinzDonawitz sludge contents (0-20 wt.%). A theoretical model is developed to estimate the wear rate of these composites under different test conditions. The results obtained from the proposed theoretical model are found to be in good agreement with the experimental values under similar test conditions. Taguchi's analysis suggests that the composition of the composite and the sliding velocity are the most significant factors affecting the specific wear rate. This study further reveals that wear resistance of neat epoxy is enhanced by incorporation of micro-sized LD sludge particles.