Experimental study on microscopic characteristics of liquid-cooled granite based on mercury injection method

To study the effect of liquid cooling, including acid cooling and water cooling, on the microscopic characteristics of high-temperature granite, scanning electron microscopy and energy spectroscopy analysis tests (SEM-EDS) as well as mercury injection experiments were carried out on liquid-cooled granite. The SEM-EDS results show that the elemental composition is barely affected by water cooling, while acid cooling causes reductions in O, Si, and metallic elements. The pores and cracks were observed in both cases. Moreover, a more non-flat, loose, and rough surface is created under acid cooling conditions compared to water cooling. Mercury injection tests show an increase in porosity, pore volume, and specific surface area in liquid-cooled granite samples, while their fractal dimensions show an opposite trend. Acid cooling leads to significantly greater property changes than water cooling, owing to the dissolution effects of mud acid. The results demonstrate that the acid cooling process results in greater capacity of pore generation and expansion, as well as lower pore structure complexity, compared to water cooling.