While the objectives of the demonstration were unclear, it’s the latest sign of the role played by resource nationalism in the shutdown of the Cobre Panama mine.

About 10% of the increase in estimate comes from the addition of rare earths minerals.

The discount hit a record high of $108 a metric ton on Jan. 8.

The country derives a quarter of its gross domestic product and 90% of exports from mining.

Junior producers have been particularly hard hit.

La Preciosa hosts one of Mexico's largest undeveloped primary silver resources and is located about 19km from the company's Avino mine.

Mansfield Consulting examined 14 potential critical mineral mines and two mine extensions, and found the long-term economic impact of operations over several decades could be nearly C$800 billion ($599bn).