Image credits: Dominik Vanyi
News Article

AHMSA Shuts Down Operations at Mimosa Mine VII

By Fernando Mares | Wed, 05/18/2022 - 14:08

After 15 years, Mine VII of the Mimosa Unit shut down operations definitively due to the depletion of metallurgical coal. For Minera del Norte, subsidiary of Altos Hornos de Mexico (AHMSA), reached an agreement with Section 303 of the mining union to reduce the impact on workers that serve at the complex. 

Within the next 12 months, the company will pay over US$5 million to approximately 500 staff and temp workers. The agreement also considers the progressive rehiring of interest workers at Mine VIII, which operates in the Conchas Sur area and has recently started operations with its first longwall to supply coal to its cocking plants at Monclova.

Planning for Mine VII started in 2001 and, after two years, development works started. In 2007, its first longwall started operations and, throughout the project's 15 years, it totaled 14 longwalls. Mine VII produced over 28 million tons of metallurgical coal throughout this period, during which it supplied AHMSA’s processing plants to produce crude steel. 


Mine VII was once considered the safest and most modern coal exploitation project in the country. It used to drill up to 1.5km for the extraction of methane gas, associated with coal, used for power generation. In 2007, the company expected production of 50 million tons of coal for 23 years of operation.


In April 2022, AHMSA announced the beginning of operations at Mine VIII. Infrastructure development started in 2015 and the company announced successful operational tests on Mar. 25, 2022. Mine VII is located at a depth of over 180m, has a 1.5km length and 167 platforms that support tunnels and protect personnel. According to AHMSA, Mine VIII was developed with the most advanced technology in the sector, featuring methane gas detection and control systems that ensure safer working conditions. After a year of ramping up, the mine will produce over 1 million tons of metallurgical coal for the next year. 

“The deposit that will operate as Mina VIII has reserves of over 100 million tons of high-quality metallurgical coal, with an expected lifetime of 30 years as the main source for the production of AHMSA’s steel,” said Arturo Arroyo, Operations Director, Minera del Norte.


AHMSA is a Mexican-based leading steel producing company founded using both public and private capital. It started operations in 1944 with the aim to become the main supplier of steel in Mexico on the back of a supply shortage caused by World War II. In 1997, the company was acquired by Grupo Acerero del Norte. Currently, it produces over 5 million tons of liquid steel a year. 

The data used in this article was sourced from:  
El Diario de Coahuila, MBN
Photo by:   Dominik Vanyi
Fernando Mares Fernando Mares Junior Journalist and Industry Analyst