Chile has 740 tailings deposits located in ten regions, which creates important challenges for the mining industry. Just as the Government introduced a National Tailings Policy in order to protect abandoned mining sites and make progress in the dialogue and early resolution of conflicts between companies and communities, there are companies focused on generating value from tailings.
Find out what Ecometales, JRI and Codelco are doing, together with Sernageomin’s perspective on this new way to address tailings, aiming at a change in the industry towards sustainable, lower impact mining.

Chile is a mining country: it is the largest producer and exporter of copper in the world, which makes this industry its economic engine. One of the greatest challenges it currently faces is tailings, due to the impact they could have on the ecosystem. There are different companies and institutions developing new processes and revolutionary techniques that seek to generate and extract value from this mining waste.

We talked with the director of Sernageomin, Alfonso Domeyko; the general manager of Ecometales, Ivan Valenzuela; the director and technical manager of JRI, Juan Rayo and the manager of Divisional Projects, Water and Tailings of Codelco, Rene Orellana to know how they are addressing this mission of transforming tailings into elements of value and the main challenges they are facing with regard to this challenge.

1. How is Chile working on this country challenge of generating value from tailings?

Ivan Valenzuela (Ecometales): Recovering value from mining waste is, with exceptions, a new challenge for Chilean mining. Despite its magnitudes, mining tailings and dams have historically been almost invisible to the national debate. Only in the last decade, as a result of the processing of environmental permits, this topic has permeated public opinion, due to the opposition that has arisen in the communities. Nobody wants to have a tailings dam near their home, nor a cell phone antenna or a landfill.

The richness of deposits in Chile meant that companies ignored the value contained in tailings. But the fall of the ore grades, the greater difficulty in their exploitation and the scarcity of new deposits have led us to look with a different eye at the potential of the huge volumes deposited. Additionally, the existence of dams in the middle of urban areas, some of them without closure plans and others that are outright abandoned, have raised the concern of the authorities.

This double characteristic of being an environmental liability on the one hand, and depositories of a potential for value on the other, is putting the issue on the mining agenda.

This is how the Ministry of Mining is promoting a National Tailings Policy that seeks to provide greater safety, strengthening its monitoring, reportability and control. Along with this, it promotes the remediation of the inactive sites through programs, tools and compensation systems and, finally, it encourages the reprocessing and reuse of deposits, creating economic opportunities.
The authorities recently launched a platform for academic consultation and exchange of innovations for tailings management in order to promote research, development and implementation of new technologies associated with tailings deposits.

The public and private initiative “Corporacion Alta Ley”, for its part, has also put the issue on the public agenda. The relevant thing about these initiatives is that they have been achieved, together with CORFO (Development Corporation of Chile) and a number of other industry players, putting the issue in discussion with all its dimensions and complexities.

Juan Rayo (JRI): There are several mining companies in Chile that are processing their tailings to obtain value from them. Among them CAP, Candelaria, Codelco and other mid-size companies. However, the value generated is still almost negligible compared to primary mining.

CORFO is committed to developing an innovation project via Codelco Tech and JRI-Ecometales, to recover the value from old and abandoned tailings, a program that is developed with the support of Alta Ley.

Rene Orellana (Codelco): There are several initiatives being developed for the purposes of improving the country’s position on this issue.

Different initiatives are being developed to find value ​​in tailings. One of them is led by Codelco which, through its subsidiary Codelco Tech, seeks to identify the amounts (concentrations or traces) of chemical elements that have been considered as part of the minerals for the future, including germanium, gallium, tungsten, rare earth and others, and establish a biotechnology process that makes its exploitation profitable.

In addition, also through Codelco Tech, research has been conducted to identify processes that allow the treatment of contact waters or discharge of tailings deposits that are profitable and/or improve the state of the art in this area.

Finally, Codelco has been implementing, for decades, processes for copper and molybdenum recovery from its tailings. Currently, in its El Teniente Division, the throughput from its tailings is approximately 30,000 tons of fine copper.

2. Do you think that our country has the potential to become a leader in this area?

Ivan Valenzuela (Ecometales): Absolutely. Chile generates 537 million tons of tailings annually. And for every million tons of tailings, it is estimated that there is a value of more than 10 million dollars. The periodic table is present in many deposits within the country.

Another thing is how we take advantage of that potential, as in other countries where value recovery from mining waste is a normal practice. For this to happen, a major change in mindset, regulations, process improvement and knowledge of markets other than copper are required.

A relevant fact to address this issue is to recognize the high concentration and large magnitudes of deposits. Of 740 tailing dams registered in the country, 10 represent 90% of the total volume, around 6,600 million tons, belonging to 4 or 5 owners, for whom the recovery of value does not seem attractive yet, especially in consideration of the risks associated with the management of its tailings and dams.

Current rules and regulations do not help either. Mining legislation assumes the exploitation of “new” mining resources, not those piled as waste. There are aspects to be reviewed in order to stimulate the exploitation of this secondary material. The participation of organizations such as Sernageomin (National Geology and Mining Service), concerned with mining safety and dam control, is highly relevant.

In relation to smaller, inactive and abandoned dams, which can be financially attractive for better deposited grades, there is a strong need to boost them so that third parties can recover value, generating a dynamic market. It should be avoided that due to lack of spur or regulations, dam’s activity is interrupted in unsafe conditions and with an impact on urban areas.

In order to take advantage of the tailings potential, the joint and determined participation of different stakeholders open to innovation in mining is required, but most importantly, with a long-term perspective, because there are many obstacles to be removed.

Juan Rayo (JRI): Chile has 16 billion tons of tailings disposed on its continental surface and it will continue to grow in the future, at 800 million tons of tailings per year.

The copper grades of these tailings have a calculated average close to 0.15% of copper and it is estimated that the proportion of molybdenum is of the order of 80 PPM, 3-5% of magnetic iron, 50 PPM of rare earth.

The resource accumulated in the tailings deposited and recoverable has been estimated by JRI in a total of USD $25B, which would be distributed between the owner of the tailing, the tailings operating company and the State of Chile (taxes).

Rene Orellana (Codelco): The concentrator plants in our country are among the largest in the world, the same for the size of some tailings deposits in the country, so the chances of generating business from this waste, transforming it into resources, are high.

The Government, through its National Tailings Policy, has been leveraging this type of business. For example, it opened the possibility that projects that are in environmental assessment processes incorporate the treatment of some abandoned tailings deposits as compensation. In this regard, more than 100 abandoned tailings deposits have been identified and, in total, including inactive and active tailings deposits, the number is estimated at over 700 tailings deposits, which at some point may be subject to treatment to find the values ​​present in tailings.

3. Do you think that Chile is working for a mining that is oriented to the control of emissions and waste, that is to say, a low-impact mining?

Ivan Valenzuela (Ecometales): More and more work is being done along these lines, incorporating measures to control and minimize impacts. What it needs to be reviewed is whether it is done with sufficient speed and proactivity, in the face of an increasingly demanding context towards extractive industries.

Tailings are an opportunity to make progress in a low-impact mining. The tailings policy could reverse the situation of abandoned dams through environmental compensation: it can promote value recovery through suitable instruments and set new standards, for example, that tailings are deposited in the cavity of the field, significantly reducing the impact of the most massive mining waste.

While there has been progress, there are difficulties of all kinds for mining to enter the circular economy. The industry has adopted “green trends” in energy, water and emissions, but the commitment to “reducing waste”, probably due to its constraints, does not permeate with the same strength in business definitions.

For this to happen, a jump in productivity, innovation and processes is necessary, with the incorporation of new players of an industrial mining nature, that do the job that mining companies won’t do directly, but acknowledging that the role and proactivity of the mining companies to generate stimulus to the ecosystem is critical.

Juan Rayo (JRI): Chile is turning very slowly towards cleaner mining, which does less damage to the environment and has a low social impact.

In JRI’s opinion, the retrieval of tailings to the mine is the key to achieving “good mining”.

Rene Orellana (Codelco): National mining has been worried about its tailings for decades. This is how, in this country, there have been large projects to increase water recovery from its tailings, in order to reduce the impact of its operations on water consumption from continental sources. It has also been seen how the use of seawater in mining processes has been increasing, for the same purpose.

Major unconventional tailings projects have also been developed (today in the country you find one of the largest, if not the largest deposits of thickened tailings) and also filtered tailings deposits. These types of deposits, and conventional tailings are developed with standards over national legislation, adopting the good international practices that are set over time.

It should be remembered that the type of deposit of upstream construction tailings, where catastrophes have occurred in other countries in the recent past, was prohibited by law in Chile at the beginning of the 70’s decade.

It has also been investigated – and there are some applications – the phytoremediation of tailings deposits, aiming at reducing the emission of particulate material from them.

Finally, a private-public project has been developed in the past three years: the Dam Project, jointly executed by state agencies (Corfo, Alta Ley, Sernageomin, DGA, SMA, Ministry of Mining, and others), mining companies (AMSA, BHP and Codelco) and Fundacion Chile, which seeks to design and implement an information platform on the status of tailings deposits for the communities and authorities, in order to bring their management closer to these stakeholders, providing them with better information on quality and timeliness.

This all aims at reducing the effects of tailings operations, with a more controlled waste disposal.

4. What are the tailings-related challenges of mining in Chile?

Ivan Valenzuela (Ecometales): The new environmental and regulatory requirements are impacting the mining map and the services needed for its development. Today stakeholders are more aware that they share the same territory and there are significant disputes regarding the use of land and the productive vocations that make sense to the communities. Mining, used to operating as an isolated structure, shares territory with tourism and astronomy in the north; or with agriculture in the central regions, and we must look for a harmonious coexistence.

There are also technical and process challenges. Given lower ore grades, it is necessary to open our minds to the recovery of a set of by-products that make the business feasible. As Chilean mining has been characterized as single-product, this is now a major challenge.

With regard to small and medium-sized mining, there shall be demands that require better management plans and adequate site closures. In this way, it is possible to create a market for processing – Enami type model – because if there is no obligation to the owners it will be difficult to think of businesses that thrive.

In short, we must change the mindset: what was once a final deposit with a series of safety measures, now needs to be “released” for exploitation, with all what it implies from a regulatory, cultural and economic perspective, among others.

Juan Rayo (JRI): To manage tailings of the central regions of Chile, which could be half of the throughput for the next decade, through schemes that don’t involve building new deposits.

The foregoing implies:
– Canting the existing deposits as much as possible.
– Retaking tailings to mine cavities.

Rene Orellana (Codelco): Ore grades are decreasing, which requires the process to increase treatment rates in concentrators and, therefore, tailings volumes also increase and must be stored in a safe and sustainable manner. Hence, the challenges are to continue to manage our tailings at the levels of safety and standards that have been used, trying to reduce the areas they occupy, optimizing water recovery from them, ensuring the physical and chemical stability of the deposits, improving our systems in the face of climate change and designing closure plans to ensure all of the above, even long after the ceasing of its operations. All this within a relevant change in our culture, from a relationship with the communities and authorities towards a commitment to communities and authorities in order to build ties that are more transparent, with clear and timely information, with signs of healthy coexistence and integration into the needs and opportunities of all parties involved.


The Chilean Ministry of Mining is working hard to generate tailings value through the National Tailings Plan. Likewise, through Corfo via the projects called Strategic Technology Programs (PTEC), for the recovery of value elements.

Also, on the Sernageomin website https://www.sernageomin.cl/datos-publicos-deposito-de-relaves/, there is complete information on tailings in Chile, which includes the public data on tailings deposits, tailings deposit guides, location maps, publications, and a section with frequently asked questions and answers on tailings.

Alfonso Domeyko, national director of Sernageomin, explains that “on these issues, we have carried out a geochemical cadastre of tailings throughout the country. On the other hand, the Institution has carried out agreements with the BGR (Federal Institute of Geosciences and Natural Resources of Germany), to geochemically characterize tailings in the Antofagasta region.”

He added that “we are working in coordination with public and private entities to develop work that positions Chile as a country that does its job seriously, through different programs and projects, for the management, monitoring, and audit of tailings deposits.

The head of the National Geology and Mining Service said that they are permanently concerned by the Ministry of Mining and especially the Minister Baldo Prokurica so that, as a country, they continue to work for a low-impact mining, and that this is reflected through the National Tailings Policy and the development of the National Tailings Observatory, which together will address abandoned tailings and active deposits, improving management and environmental conditions.

Regarding the main challenges of mining in Chile in relation to tailings, Alfonso Domeyko explained that “it corresponds to the implementation of the National Tailings Observatory, where they plan to monitor the operating parameters of the deposits online, as well as the chemistry of the surrounding water. There is already a first big step with the Dam Project, where it has been proven that private and public work comes to fruition, and that is the path we must continue to manage.”