Compañía Minera Cuzcatlán exports silver and gold concentrates mainly to South Korea and Germany from its “green” mine in San José del Progreso, the sixth largest silver producer in Mexico and located in the state of Oaxaca.
Cristina Rodríguez, deputy director of Sustainability of the company, qualifies it as green for several reasons, the first of which is because Fortuna Silver, the parent company of Canadian origin, initially determined that it was underground, with a higher implicit cost, but also with more environmental benefits compared to the option of going under the open sky.
Therefore, if you look at it in a panoramic way, the mine comes to have a greenish landscape in its surroundings, without being completely isolated, because it is located less than five minutes from San José del Progreso, coexisting with the community in a way comparable to what that it would be an industrial plant on the outskirts of a city.
In that region, below the ground, there is a certain balance in the aquifers that reflects two environmental actions of Compañía Minera Cuzcatlán: the operation of a water treatment plant and the reuse of this vital liquid in the mine facilities.
“It’s as if the company won a silver medal,” is proud Rodríguez, who prefers this metal and not gold, referring to the fact that the mine is predominantly a silver producer (7.9 million ounces in 2019), with secondary extractions such as the gold itself.
Compañía Minera Cuzcatlán, from heaven and earth
In the San José mining complex, water comes from two main sources: the collection of rainwater and the recovery of up to 96% of the water that enters its mining process.
In turn, Compañía Minera Cuzcatlán is supplied with water from the sewage treatment plant in the Ocotlán de Morelos thanks to an agreement with the municipality of the same name. This treatment plant has provided, since 2010, almost 8% of the water needed for the San José mine. The rest of its needs (82%) are covered with a closed water circuit, so it does not discharge effluents thanks to reuse.
Compañía Minera Cuzcatlán operates and maintains the treatment plant on loan and water is also used from it for irrigation of public gardens and for other uses in the municipality.
Taking care of water has a reason in the context: the Central Valleys of Oaxaca, where the mine is located, are a region with high water stress.
So that in summary and consequently, to satisfy the industrial water needs of the San José mining complex without competing with the surrounding communities, Compañía Minera Cuzcatlán made the decision to capture, treat and reuse the wastewater discarded by the municipality of Ocotlán de Morelos, also have a sustainable cycle of water use with zero discharge.
“The reuse of water is possible because we do not use chemical, toxic or dangerous substances in our processes, that allows us to use water over and over again,” says Rodríguez. Of all the water that reaches the mining facility, only about 4% is lost, by evaporation or contained in the minerals or tailings (they are not completely dry, because otherwise they would fly as microparticles).
Although the use of cyanide is governed by safety procedures and international standards, Compañía Minera Cuzcatlán does not use this substance to separate the minerals; It does so through a safe and environmentally friendly flotation process.
Flora and fauna
Compañía Minera Cuzcatlán is carrying out a reforestation program that includes planting 13,500 native species from the Central Valleys of Oaxaca, in an area of 15 hectares in 2020, including huamuche, guaje, mesquite, nopal, jarilla and copal. In the last three years, it planted 25,000 trees on 22.5 hectares.
In general, the landscape is dominated by crops, human settlements and scarce vegetation, typical of the dry temperate climate. Cold climate trees such as casuarina and shade trees such as junipers, ahuehuetes, laurels, jacarandas, framboyans and tulips from India stand out, as well as auates, huamuchiles, magueyes, lianas and mesquites.
“Compañía Minera Cuzcatlán has reforested, because the law also requires it to do so; but it has taken special care of the fauna beyond the legislation”, affirms Rodríguez.
The wildlife there is made up of plain animals such as rabbits, opossums, badgers, armadillos, gophers, skunks and field rats, as well as species typical of this type of environment such as thrushes, chigüiros, carrots, sparrows, huilotas, sparrows, goldfinches and chupamirtos and pigeons, among other plains birds.
Compañía Minera Cuzcatlán started production at the San José mining complex in September 2011 and at the end of 2018 had produced 35.9 million ounces of silver and 269,000 ounces of gold. The mining method applied in the exploitation of the veins is cutting and filling with a mechanized extraction methodology.
The mine’s production capacity has been increased twice; in September 2013 it was increased to 1,800 tons per day and, more recently, in June 2016, the production capacity increased to 3,000 tons per day, through an expansion of the plant, allowing a daily production of approximately 80 tons of silver and concentrates.
In May 2018, a third stage filtered dry-pile tailings facility was commissioned on time and on budget with increased filtered tailings capacity to handle 1.5 years of production with more expansions planned for 2019 and 2020 that would be sufficient. to store all tailings for the currently defined life of mine plan.
The mining operation has been developed in strict compliance with the regulations and permits required by government agencies involved in the mining sector. In addition, all the work follows the international quality and safety standards established in the ISO 14001 and OHSAS 18000 standards.
Rodríguez is an environmental engineer. She argues that mining serves the development of humanity and the ideal is to seek to avoid or, when this is not possible, minimize the impact it generates on the environment.
She is simply satisfied: “Ever since one studies this career, one has many ideas and dreams in mind. Now I see them materialized”.