Estudo Da Contribuição Hídrica Nas Cavidades De Máxima Relevância Em Unidade De Mineração No Pará. Study of the Water Contribution in the Cavities of Maximum Relevance in a Mining Unit in Pará

The Carajás Mining Complex, located in the Carajás National Forest, in the state of Pará, in a Federal Conservation Unit, occupies about 30 preserved hectares, where there are several animal species and about 300 natural cavities, popularly known as caves. Caves are classified according to their degree of relevance in maximum, high, medium or low and must be protected due to their ecological, biological attributes scenic, historical-cultural and socio-economic aspects. Vale, in its Vale Production System (VPS) management system, defines process safety events as those in which there is an unplanned release of energy and/or materials from its operations. The mining complex has some facilities located close to these previously mentioned cavities, some within its area of influence identified in the hazard identification and risk analysis (HIRA) studies, especially in the evaluation item of consequence analysis studies. As a result, process hazards that may infringe damage to these cavities are mapped as process hazards and the risk assessed and classified. Therefore, this work aims to carry out a more in-depth study to enable us to revisit the identified hazards in non-obvious dimensions, assess risk and acceptability and from there define additional actions to ensure that cavities are not subject to irreversible negative impacts from ore processing. An example of non-obvious danger would be scenarios in which water or aqueous tailings from ore processing or both, may enter the caves from pipelines, pipes and process drains and that may cause damage to their characteristics that make them unique and heritage of the country.