The influence of binder type on the properties and performance of taphole clays for blast furnaces

Abstract

Taphole clay (THC) is an unshaped refractory commonly used in blast furnaces to seal the taphole after the tapping process has been completed. THC is typically bonded with conventional coal tar pitch (CTP), but alternative binders have been developed due to the high toxicity of this material. This study investigated the performance of various binders commonly added to THCs, including CTP, phenolic novolac resin (PNR), low benzopyrene coal tar pitch (ECTP), and a petroleum-based binder (PBB). The properties of the prepared THCs were investigated, and the analytical hierarchy process was used to infer the behaviour of the prepared materials during blast furnace operation. The results obtained show that the best binder for a particular THC depends on its operational requirements. In cases where excellent injectability and hearth protection are mandatory, CTP or ECTP are highly recommended. Conversely, if a low-toxicity and easy-to-drill THC is required, PBB emerges as a promising binder. PNR is the recommended choice for blast furnaces where rapid cure and tapping stability are priorities.