Thermal Behaviour of Oyster Shell as an Abrasive for Industrial Grinding Wheel

Abstract

Demand for products with excellent dimensional accuracy, structural stability and surface integrity makes hard and brittle abrasives for grinding wheels to be highly sought for which becomes more attractive when recovered from wastes for cost reduction and environmental sustainability. It is challenging to control generated heat during grinding operations, hence, thermo physical stability of grinding wheels made from Oyster shell abrasives(OSA)is hereby studied. Aimed at producing wheels with potentials to compete favorably with those made from mineral abrasives associated with high cost of production, health and environmentally threatening liabilities. Samples were made from a ternary mixture of ground Oyster shell as abrasive, Bakelite powder as Binder and two plies of Glass fiber as reinforcement through hot pressing. Formulation with 60% OSA offered 79 Shore D hardness and wear rate of 0.0002g/min which were superior to a commercial product. Microscopic evaluations revealed an even distribution of pores and the OSA grains in the Bakelite matrix with DSC results demonstrating a thermal conductivity of 0.1232W/m/K. TGA results showed a two-step thermal degradation. First was loss of moisture at 1.432mg by weight at 211.85 o C with second step being thermal decomposition of 6.352mg showing a thermal stability of 53.16% at 418.70 o C.