The combination of new extraction technologies and rising mineral market values—especially for metals—has created profitable processing opportunities for old mining waste rock dumps, potentially turning them into valuable assets. Mining materials that were economically unviable a few years ago can now be leveraged with more cost-effective concentration and recovery techniques, benefiting additionally from favorable market prices.
Moreover, certain elements—rare earths, tantalum, tin, tungsten, gold, silver, and by-products like feldspar and silica—have seen later commercial interest and were initially overlooked. Almost any mineral resource can now be re-evaluated: gold, sulfides, iron, and others can all be recovered using the right techniques.
We offer pilot plants to test the effectiveness of the proposed treatment before full investment. This allows for investment in the correct technology with a clear understanding of expected results.
The techniques generally start with crushing and/or grinding, followed by gravity concentration, magnetic or electrostatic separation, optical sorting, flotation, and leaching for precious metals in increasing order of complexity. Additionally, these projects contribute to environmental restoration by substantially reducing waste volume, as certain products or by-products are sold off, and new waste generated in the concentration phase can be encapsulated.
Any recovery effort requires a detailed study that includes mineralogy, testing of different techniques, and an industrial interpretation of results, which are then translated into equipment selection and sizing. Any project phase can be analyzed and offered for consideration.
Recovering minerals from waste rock can extend the operational life of mining projects.
Reduces the risk of landslides or collapses that could impact nearby communities, infrastructure, or waterways.
Enhances the reputation of mining companies, allowing them to position as responsible and sustainable enterprises to communities and regulators.
Recovery of valuable materials can generate additional revenue and reduce the need for new extractions.
Helps reduce soil, air, and water contamination by stabilizing or removing toxic materials that might otherwise disperse into the environment.
This former mining complex, active from 1880 to 1970, housed key industrial facilities for lead and zinc smelting and the production of sulfuric acid and copper sulfate, among others. Waste from these smelting operations, primarily slag, accumulated across the 50-hectare site, reaching depths of up to 50 meters and containing significant amounts of potentially recoverable metals.
In 2013, MINEPRO coordinated a geophysical survey to design an optimal sampling plan. This was followed by chemical characterization and laboratory flotation and leaching tests to recover metals (Cu, Au, Pb, and W) and rare earth elements.
The Filón Sur deposits, exploited during the 1980s and 1990s, were accompanied by mineral treatment facilities that included leach piles containing several hundred thousand cubic meters of crushed ore. This ore was treated with a cyanide solution to recover the contained metals (Au and Ag). However, the low efficiency of this leaching technique left high metal concentrations in the material, which remains viable for reprocessing and recovery.
Between 2013 and 2014, MINEPRO actively participated in the project’s environmental processing documentation. The team designed a sampling and characterization plan for the leach piles, followed by a program of spiral gravity concentration and concentrate leaching tests. These tests yielded key parameters for the basic engineering design of treatment facilities and a preliminary feasibility study, both carried out by MINEPRO.
Historically mined for tin, operations at this site have generated several waste deposits in the form of ponds and rock dumps. These deposits contain tin and tantalum (cassiterite and columbotantalite), which are of considerable interest for metal recovery and commercial concentrate production.
Throughout 2013, MINEPRO developed and executed a laboratory and pilot plant testing program focused on the gravity concentration of tin and tantalum minerals from one of the site’s ponds. Additionally, a conceptual design for a treatment plant to reprocess mining waste was completed.
