Nucor Corp.’s St. James Parish plant produced 4.55 million tons of direct reduced iron, with peak operating rates exceeding 90 percent of capacity, the company reported Thursday.

The St. James facility’s performance was included in the highlights of Nucor’s first-quarter earnings report. The company said the plant achieved that production while achieving “world-class metallization and carbon percentages.”

The plant burns natural gas to heat iron ore to temperatures high enough to burn off carbon and oxygen. The reduction process results in high-purity pellets from iron ore. Nucor mixes the pellets with scrap metal to make steel. The St. James facility began operations in late December, three months later than originally scheduled. The delay was caused by a storage dome’s collapse.

Nucor reported first-quarter earnings climbed to $111 million, or 35 cents per share, from $84.8 million, or 26 cents per share, a year ago.