The problem of flyrock in a limestone quarry in Northern Italy: analysis of the causes and mitigation interventions

The mining activity in a quarry in Northern Italy involves the excavation of limestone by drilling and blasting for cement production. In the context of this activity, a recent accident involved the projection of rock fragments outside the quarry area during a production blast. The accident is attributable to evident inaccuracies in drilling that led to the failure to comply with the parameters established in the authorised blast scheme. According to what was observed on site, the leading causes of these inaccuracies are due partly to possible deviations of the holes during the drilling phase and partly to the lack of regularity of the excavation faces. The paper proposes new blast schemes to continue the activity. These schemes are a solution and a call for expertise and skill. Knowledge and commitment are crucial in ensuring the success of these schemes, which are designed to eliminate or at least reduce the effect of the two factors (deviation of the holes and irregularity of the residual faces) during the execution of the production blasts.