The miner said the approval comes after its work to raise the site's dam at the Step 3 licence area.
The tailings dam has a downstream construction design and is an embankment dam structure. It is being built with compacted imported earth fill material and granular materials for its drainage and filter zones.
"Tailings are not used to build the dam, and instead construction materials are placed in controlled layers," the miner said of the project.
"This is a conservative and high-quality design for a tailings dam, being designed and built as a water-retaining type of dam."
Regulatory authorities in Brazil granted the installation licence for the dam work in January 2018. Construction was completed in August 2019.
Bulk commodities CEO Seamus French said Minas-Rio produced 23 million tonnes in 2019.
"This is an important milestone for our Minas-Rio iron ore operation in Brazil towards reaching its full potential. Minas-Rio has a long asset life of 48 years and produces a high grade, premium quality product for our customers, supporting lower emissions in the steel industry," he added.
Minas-Rio operates a comprehensive tailings safety management programme as required by Anglo American's Group Technical Standard. Also in compliance with Brazilian legislation and global best practices, the programme includes daily inspections, weekly instrument reading and geotechnical inspections at least every two weeks, along with quarterly inspections.
Minas-Rio was cleared for restart in December 2018 after idling the mine for the extensive repair of an iron ore slurry pipeline that reached from the mine to its port.