Codelco's decision comes after an incident on June 9 when 115 people, mostly school children, suffered sulphur dioxide poisoning released by heavy industry, provoking the closure of schools in the area.
It was the second such incident in a matter of just three days.
Sulphur dioxide is a classic air pollutant usually linked to the burning of fossil fuels.
Greenpeace described the area around the Ventanas plant as "Chile's Chernobyl" following a serious incident in 2018 when around 600 people in Quintero and Puchuncavi received medical treatment for symptoms such as vomiting blood, headaches, dizziness, paralysis of their extremities and strange red marks on children's skin.