ST. PAUL  — The Minnesota Department of Natural Resources has rejected a request for a full environmental review of a proposed taconite mine expansion in northeastern Minnesota.

Environmentalists argued a more thorough study of the project is needed because the expansion would dig up rocks containing sulfur. Northshore Mining wants to expand its mine near Babbitt in St. Louis County by 108 acres. Parent company Cliffs Natural Resources said that would allow for five to 10 more years of mining.

Northshore sends crushed ore from the mine by train to its plant in Silver Bay, where it produces taconite pellets that are shipped to steel mills in the lower Great Lakes.

The DNR said it has adequate information from an environmental assessment and doesn’t need the full review.