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StocksMedium•22 October 2026•
3 min read

Southern Copper studies $680 million expansion of Cuajone mine in Peru

Key Facts

1Southern Copper is studying a Cuajone expansion at an estimated capital cost of $680 million.
2The proposed expansion would raise daily milling capacity from 90,000 to 120,000 tonnes.
3Mined copper production totaled 693,602 tonnes in the first nine months of 2026, down 2.9% year on year.
4Net income reached a record $1,801.8 million in the third quarter of 2026.
5The company expects the Tia Maria project to start operations in the first half of 2028.

Southern Copper is studying an expansion of its Cuajone mine in Peru's Moquegua region at an estimated capital cost of $680 million, according to its third-quarter earnings filing published in October 2026 with the U.S. Securities and Exchange Commission. The project study comes as the company attributed lower output at its Peruvian operations to declining ore grades. The proposed expansion would raise the mine's daily milling capacity from the current 90,000 tonnes to 120,000 tonnes. The company said implementation would require "additional mining equipment and a new production line" at the concentrator. The project estimate links the expansion to expected average annual production of 55,000 tonnes of copper. The estimate also includes average annual production of 1,400 tonnes of molybdenum under the project, which remains under study.

Company-wide mined copper production totaled 693,602 tonnes in the first nine months of 2026, according to the third-quarter earnings filing. Output fell 2.9% from the same period a year earlier. Second-quarter results, released in July, had shown mined copper production of 461,206 tonnes in the first half of 2026. Output at that point was down 3.8% year on year, according to the company's earlier filing. The year-on-year decline in cumulative output through the end of September therefore narrowed compared with the decline recorded for the first half, while production remained below its year-earlier level.

In financial results accompanying its project update, Southern Copper reported record quarterly net income for the third quarter of 2026. Net income reached $1,801.8 million, according to the company's earnings statement filed with the U.S. Securities and Exchange Commission. The company attributed the record earnings to higher sales during the period. Third-quarter net sales totaled $4,696.6 million, according to the same filing. Operating cash flow reached $2,224.3 million in the same quarter as the company continued capital spending on its investment program.

Southern Copper's capital investment program for the current decade exceeds $15 billion and includes projects in Peru and Mexico, according to the company's filing. Cumulative capital expenditure in the first nine months of 2026 reached approximately $1,380.5 million through the end of September. At Cuajone, ongoing studies extend to a larger expansion option than the proposed daily capacity of 120,000 tonnes. The company said it was also studying the feasibility of raising daily milling capacity to 150,000 tonnes. That option remains part of the company's feasibility studies, alongside its assessment of the expansion for which it has set an estimated capital cost.

The Tia Maria project was 49.6% complete as of September 30, 2026, according to the company's update in its third-quarter results. Southern Copper had forecast in its second-quarter earnings filing released in July that operations would begin in the second half of 2027. It said at the time that "operations are expected to begin in the second half of 2027." The latest earnings filing gave a later start date than that earlier forecast. The company now expects Tia Maria to start operations in the first half of 2028.