Evaluation of damage of almandine garnet grains by N2 adsorption method

Abstract

Damage of abrasives (e.g. garnet abrasive) represents a current problem in the AWJ technology. Due to this, possible reuse of the garnet recyclated from sludge after the cutting by the AWJ technology is investigated. Geological origin and material properties of almandine garnets (mineralogy, granularity, grain shape and others) influence this technology significantly. New parameters of input materials, such as the specific surface area and pore distribution (criterion of the internal grain damage), are examined by the N2 adsorption method for the evaluation of damage of abrasives. Parameters of the input abrasive of almandine garnet AG80 and its recyclates AGR1 and AGR2 were compared in order to determine the degree of the internal grain damage. Results of measurement of the input abrasive AG80 showed that it is a nonporous or macroporous material with minimal damage of grains. For the recyclates, the damage of grains was evident. After cutting and subsequent recycling of garnet grains, the pore structure occurred probably due to drop out of inclusions from the garnet structure or development of a network of slits/cracks.