Brazilian miner and iron ore producer Vale said this week it is currently monitoring its Gongo Soco mine, following “movements” in both the primary and secondary parts of the mine’s northern slope pit.
“The northern slope continues to slide into the structure, a process that has been taking place gradually since last year,” the company said.
Vale said it is assessing the eventual increase of such movements at its Sul Superior dam, which is nearly a mile (1.5 kilometers) away from the moving slope pit.
“The pit and the dam are remotely monitored 24 hours a day, using radar and a robotic station capable of detecting millimetric movements, as well as by drone surveillance and by the Geotechnical Monitoring Center,” it noted.
Vale’s Sul Superior dam is at No. 3 emergency level, which means the dam may collapse at any time.
Vale said it finished the construction of a containment structure 3.7 miles away (6 km) from the Sul Superior dam. The structure’s effectiveness is yet to be evaluated by authorities.