Enhancing the thermal conductivity of clay using iron phosphate as an additive

Abstract

Clay has been a close companion in human endeavor form millennia. Clay’s highly porous nature, environmentally friendly extraction, and waste-free disposal have made it a promising material in the journey towards sustainability. Clay is already being used as carbon dioxide trappers as well as green catalysts for well-known organic reactions [1]. One of clay’s most prominent applications is being used as heat transfer interfaces, in cookware, nuclear waste containers, and geothermal borehole heat exchangers, etc. [2], [3]. However, the low thermal conductivity of clay makes it a less efficient heat transfer material, which is addressed in this study by incorporating iron phosphate as an additive. Iron phosphate used in the study was obtained as a byproduct from Alpha titanium bis(hydrogenphosphate) monohydrate, α-Ti(HPO4)2•H2O, α-TiP synthesis using alkaline roasting of ilmenite [4]. This process yields a phosphoric leachate that contains iron phosphate. Thus, this study valorizes a highly acidic byproduct while improving the heat transfer capabilities of a sustainable material; thereby further aligning the objectives of the study towards sustainability.