APPLICATION OF ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY FOR THE IDENTIFICATION OF BONDING AGENTS IN MAGNESIA-CARBON REFRACTORIES

摘要

Bonding agent is playing a very vital role for the performance of magnesia-carbon refractories in the lining of converters, ladles, electric furnaces, and other metallurgical units. In such materials, the bonds between the refractory oxide particles and the solid carbon-containing substance are realized using a carbonaceous binder which is subjected to transformations according to the oligomer-polymer-coke scheme due to thermal effects in a non-oxidizing atmosphere. Many a times reverse engineering is essential to identify the type of organic binder used in the magnesia-carbon system for benchmarking the product due to its excellent performance. Therefore, a confirmatory test is required to identify the same. In this paper, Electron Paramagnetic Resonance (EPR) spectroscopy which is a very powerful tool for detecting paramagnetic species has been successfully applied for the identification of type of bonding agents used in the magnesia-carbon refractories. Resin bonded magnesia-carbon brick shows very weak EPR signal, whereas, pitch bonded magnesia-carbon brick exhibits very strong EPR signal due to the formation of paramagnetic centers.