Determination of adhesion in bitumenmineral systems by heat-of-immersion calorimetry

The strength of chemical bonds formed between eight rock-forming minerals and six bitumen samples were examined by heat-of-immersion calorimetry. The materials were characterised by their physical and chemical properties. The amount of energy released by the bitumen-mineral interaction was much larger than expected for an immersion reaction, exceeding usual values by a factor of up to 10². An oxidation mechanism, catalysed at the mineral surface, is proposed to account for this observation, and trends in the heat-of-immersion data are correlated with chemical properties of the bitumen and mineral samples.