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natural capital

GRI 103-2, 103-3 SDG 11.6

Preventing impacts on the environment and using natural resources consciously is an increasingly urgent concern on the planet. Five out of the ten main risks that comprise the risk matrix presented at the 2020 Global Economic Forum are environmental: extreme weather, climate action failure, natural disasters, biodiversity loss, and human-led environmental disaster.

For this reason, we are committed to improving our environmental monitoring and the results of our indicators, so as to contribute more to future generations. We want to be a company recognized for its sustainable conduct, one that builds the eco-efficient mining of the future, with fewer resources consumed and less waste generated.

We are in the process of reviewing our environmental goals. However, in this last cycle, we continue with the goal of reaching, by 2025, 75% of recirculation and less specific use of water; reduce the specific emission of greenhouse gases by 5%; reduce the disposal of tailings in dams and decrease the specific generation of mining and metallurgical waste by 50%; in addition to ensuring that all the units have an alternative study for future use and a decommissioning plan, aligned with the development of the surrounding communities where we operate.

Our Integrated Management System is based on a policy that establishes the guidelines that steer the way we do business, focusing on management of quality, the environment, and occupational health and safety, and social responsibility. In addition, we are guided by environmental laws and regulations relevant to our business in each country where we are present. SDG 13.2

All operational units are ISO 14001-certified, therefore we follow globally recognized compliance systems and standards that support us in achieving our goals. On an annual basis, each unit undergoes an assessment of compliance with environmental legislation and commitments, conducted by an outside company. Every two years, the units’ Environmental Management System is audited internally. Each year, a self-assessment is carried out to identify opportunities for improvement and, following the Precautionary Principle, to ensure that we adopt appropriate measures to prevent environmental degradation. GRI 102-11

We invest not only in innovation projects, to contain the advance of climate change, but also in Environmental Education Programs (“PEAs”), aimed at raising awareness and changing habits in the communities. In 2020, we earmarked US$ 42.8 million in investments and environmental expenses, of which 22% were used for waste disposal, 18% for environmental management, and 17% for wastewater treatment.

For 2021, we have already approved the “Vazantes Mineiras” project, a project linked to decommissioning initiatives, with multiple land uses, even during mine operation, which will integrate the area’s environmental, social and economic issues. This is an innovative vision, anticipating the implementation of future uses and enabling the development of a new business model. The initiative is divided into four modules: research, planting and production, tourism, and social.

Legado das Águas
Environmental investments GRI 103-2
Environmental expenses GRI 103-2

Water Resources Management
MATERIAL TOPIC GRI 103-2, 103-3, 303-1 SDG 6.a, 9.4

Water remains a central theme for Nexa, and is part of our Sustainability Master Plan, which outlines guidelines for the conscious use of water. As part of our commitment to the sustainable management of water resources, we carry out relevant socio-environmental projects in this area, such as Jovens Cientistas (“Young Scientists”), Gente Cuidando das Águas (“People Caring for Water”), and the Água Boa (“Good Water”) Support for Public Management (details on the projects can be found on page Social Capital and Relationship). Committed to disseminating this issue to the mining sector, we spearheaded the coordination of the technical group of the Brazilian Mining Institute (Ibram) that deals with this issue, having made a public commitment last year to develop more sustainable mining.

In a year in which several external actions had to be postponed due to the pandemic, we sought to focus our work on internal actions to raise awareness and reduce consumption. Among our goals of ongoing improvement in reducing water use in all of our operations, we have already achieved the target set for 2025, which was to reach 75% water recirculation. In December 2020, we reached 82%, a significant gain compared to the previous year (67% recirculation). GRI 303-2

Several ongoing improvement actions contributed toward the improved index, such as control of wastage and use of new water only when recirculated water cannot be used. The percentage indicators for recirculation and specific use of new water (m3/t) are systematically monitored in an integrated corporate database.

Legado das águas

In 2020, we received the seal as a founding company of Legado das Águas (“Legacy of Water”), the largest private reserve of Atlantic Forest in Brazil (nearly 1% of the total), with 31,000 hectares of protected woodlands and Brazilian biodiversity. The seal was awarded by Reservas Votorantim to Group companies that support the initiative. Aside from preserving water, Legado das Águas promotes development of the economic activity of riverside communities, with a high level of engagement of the populace in the expansion of local tourism and in the preservation of nature. Since 2012, Nexa has contributed R$ 10 million to support the initiative, with more than R$ 2 million in 2020.

Legado das Águas has become a Brazilian benchmark in environmental asset management, due to the business model that uses standing forests as a means of innovation in ecotourism, scientific research, and socio-economic development. Scientific research and monitoring of flora and fauna have already registered 1,765 species in the Legado area, 50 of which are endangered animal species and nine are endangered plant species. Recognized as an Outpost of the Atlantic Forest Biosphere Reserve by the UN/Unesco system, it recently found two albino tapirs, possibly the only two in the world, and rediscovered a species of orchid thought to be extinct in the wild.

Water Catchment in Vazante SDG 11.6, 15.1

We continued monitoring the Santa Catarina River, supporting the study that has been conducted by the Institute for Technological Research (IPT) to assess the impact of river drying in the region, due to the reduced volume of rainfall in the drainage basin and the phenomenon of sinkholes, which are depressions that characteristically occur in limestone-rich soils.

We have a project to recover headwater sources of the Santa Catarina River, which involves an area of 50,000 hectares, with 134 springs, over a five-year period. For 2020, we protected 27 springs by constructing 19,900 meters of fence, to begin installing flow monitoring points.


We are aware that the management of tailings deposits and dams is one of the main risks associated with mining activities. Accordingly, in 2019 we reviewed the management process, completed the installation of sirens and mandatory mass evacuation drills with the populace living in the surrounding area. In 2020, due to the pandemic, we were unable to carry out the simulations involving communities. However, we continue carrying out all inspection practices, and have evolved in the instrumentation of the Vazante and Morro Agudo dams, implementing online monitoring.

In order to control and monitor our dams and tailings deposits, we apply guidelines from the International Commission on Large Dams. Additionally, we implemented our Six Golden Rules for Managing Tailings Deposits and Dams, which are mandatory and entered into force in 2020. In the event of any transgression, the case will be evaluated by a local committee, which will decide the disciplinary measure to be adopted.

With the aim of bringing greater transparency and visibility about our dam management, we developed a website that features information on our operations. For example, it is now possible to have online access to the result of the geotechnical stability report of the dams (nexadams.com).

We currently use three waste disposal methods in our operations: return to the mine, by filling the spaces where the mineral was removed (known as backfilling), dry stacking, and dams. For all our control and monitoring methods, we follow the laws in force in each country where we operate.

Some operations may combine one or more disposal methods. At the Atacocha, El Porvenir and Cerro Lindo units in Peru, we adopted the backfill system, whereby 21% of the tailings are returned to the mines at the Pasco Complex (Atacocha and El Porvenir), and 38% is returned to the Cerro Lindo mine, in which part of the waste is filtered, separating water and solids. The water is recirculated and the filtered tailings are sent to the dry stacks to be compacted. This same model will be adopted in the Aripuanã operation, still under construction. At the Vazante mine, we started the dry stacking method, thereby reducing environmental impacts and risks to the operation.

Reuse of material

As a priority, we seek to reuse tailings/waste by using new technologies. When this is not technologically applicable, the material is disposed in such a way as to contain environmental impact and to pose lower risk, such as dry stacking. Dams are resources that we avoid using; when they are necessary, we build them in a single stage, using downstream elevation or centerline method. Currently, only 34% of the tailings generated by Nexa in Brazil and Peru are sent to dams, as other disposal technologies are mainly used.

The Management Team regularly monitors this issue, through structure stability reports, presented in monthly reports. We use processes and procedures that form the Integrated Dam Management System (called SIGBar) and an Integrated Deposit Management System (called SIGDep), permanently monitored by an independent firm, which receives inspection data every 15 days and monitoring by monthly instruments, respectively, to issue its reports.

Cerro Lindo Unit

Waste and Tailings Management
MATERIAL TOPIC GRI 103-2, 103-3 SDG 9.4, 12.4, 12.5

We remain committed to developing new technologies that allow us to reduce our waste volumes and transform them into secondary products, to be marketed. To develop these new products and improve the existing ones, we rely on our innovation platform — the Mining Lab — which selects start-ups with unique solutions for different purposes, in addition to partnerships with universities and research institutes.

Several products that originated from these research projects are currently being developed, such as the production of sulfoaluminate pre-clinker for application in concrete, and synthetic granite for the construction industry, made from the tailings at the Três Marias unit; and the separation of hematite from the tailings generated at the Vazante mine for use in the steel industry (details on the projects are found on page Technology, automation, and innovation).

In 2020, our operations generated around 19 million tonnes of mining and smelting waste, 82.1% of which were hazardous and 17.9% were non-hazardous, a 7.9% total reduction compared to 2019. GRI MM3

Recovery and reprocessing

Cerro Lindo – In order to increase the circular economy in our operations, we conducted a study to reuse the barium sulfate (baryte) contained in the tailings from the Cerro Lindo unit. We find between 10% and 20% baryte that can be used, with economic, social, and environmental benefits. The results of the research at pilot plants show that it is possible to obtain a baryte concentrate with commercial interest; however, this is not yet economically viable. The studies will continue in 2021.

Juiz de Fora – At our materials recycling unit, we aim to increase the percentage of production from secondary material to 33% by 2023 and 40% by 2025. In 2020, we recycled 13.4% of the waste from Electric Arc Furnace Dust (EAFD), 0.41% of the brass oxide, 0.8% of the imported Waelz oxide, and 1% of the low-grade silicate.

Morro Agudo – We transformed all the tailings into a secondary product, Agricultural Limestone Powder, from which Zincal200 is derived. The tailings from the mining operation are sedimented, part of which is reused in the plant and part of which is sold as Zincal, a product used in agriculture to decrease soil acidity and increase yields. In 2020, we reached a record in the sale of Zincal, which allowed us to reduce the volume of old stockpiled tailings. Last year, we passed the milestone of 1.3 million tonnes of limestone sold, and doubled the reprocessing of old tailings at the plant. GRI 102-2

Vazante – We developed the mechanized mining method and mineral processing technology to produce zinc by means of reprocessing tailings from the Aroeira dam. The extra zinc production contributed to the Vazante unit and surrounding community, generating more direct and indirect jobs. In this process, part of the tailings removed from the dam is transformed into concentrated zinc, and the other part is transformed into dry-stacked tailings, a safer and more sustainable process. In 2020, roughly 111,000 tonnes of tailings were reprocessed, generating approximately 7,000 tonnes of zinc concentrate with a content of 39% and 104,000 tonnes of dry tailings.

Volume of waste (thousands of tonnes) GRI 306-2, MM3

Climate change

Climate change has been the subject of frequent discussion and, has increasingly gained relevance in the mining sector. Recently, it has become a key issue for Nexa, which will start reporting its indicators in a more comprehensive way. Aware of our role in containing the advance of global warming, we have developed actions to reduce energy consumption and pollutant emissions in our operations.

We want to reduce the air polluting load by increasing the percentage of renewable energy at mines and smelters and decreasing the pollutants released into the atmosphere, as well as increasing energy efficiency by avoiding the use of non-renewable energy. Moreover, we intend to reduce significant incidents that may impact climate change, and to increase preventive management in the use of resources in the area of influence, through changes in people’s behavior and lifestyle.

In 2020, we started using the GHG Protocol calculation tool at all operational units, considering new sources of energy consumption and greenhouse gas emissions. This effort was carried out by the Environment team, with a strategic vision and reflecting our concern for the sustainability of our business.

GRI 103-2, 103-3 SDG 11.6, 13.2

In pursuit of a low-carbon economy, we set a target of reducing greenhouse gas (GHG) emissions by 5% per tonne of product by 2025.

One of the main actions in this regard is the operation, beginning in 2017, of a biomass boiler (eucalyptus chips) at the Três Marias unit, replacing boilers powered by petroleum-derived fuel. Considering the operating period (2017 to 2020), the equipment provides US$ 4.3 million in savings each year, with an 81% reduction in emissions of greenhouse gases and a 44% reduction in the cost of steam production. At the Cajamarquilla unit, we are implementing the project to replace diesel oil, fuel oil and LPG with natural gas. At Juiz de Fora, in 2020 we started the implementation of a gasifier that will reuse energy waste from Nexa and the city of Juiz de Fora as fuel. ODS 7.2, 9.4, 12.2

We have also advanced in the use of bio-oil (eucalyptus biomass pyrolysis oil), in a pyrometallurgical process at the Três Marias unit, replacing the consumption of fossil fuel oil. We began testing the use of hydrogen in vehicles with direct injection into the engines, reducing the consumption of diesel oil and, consequently, the emissions of greenhouse gases.

We implemented actions to optimize the transport of inputs at the Cerro Lindo operations, which allowed us to achieve a significant reduction in the transport flow, thereby reflecting a reduction of roughly 28% in GHG emissions from this activity. This project will be expanded to the Atacocha and El Porvenir operations.

We are working toward signing a new electric energy contract for all Nexa operations in Peru, and we have a partner who supplied us with 100% of the electric energy from renewable sources in 2020. In Brazil, the consumption of renewable electric energy was nearly 96.8%, totaling an overall consumption of 98.5% renewable electric energy for Nexa, of the total consumed. We also advanced in projects such as the installation of solar panels at Três Marias and Vazante, with the aim of maintaining the basis of the renewable energy matrix. We intend to extend this pattern of projects to other units, through partnerships with companies specializing in solar energy.

We consumed 17,874,424.72 GJ of thermal energy in our operations, of which 12,958,576.06 GJ were from renewable sources and 4,915,848.65 GJ were from non-renewable sources. Our energy intensity was 30.54 (GJ/t zinc and zinc oxide sold). The increase in thermal energy consumption, compared to 2019, is mainly due to the more refined mapping of inputs used. GRI 102-1, 102-50, 102-51, 102-52

Atmospheric emissions

Our greenhouse gas (GHG) emissions totaled 773,391.154 tCO2e, which meant a 24% decrease compared to the previous year (1,017,744.42 tCO2e). The reduction is mainly attributed to the temporary suspension of mining activities in Peru for two months, which has been a consequence of the declaration of a national state of emergency due to the Covid-19 pandemic.

Emissions from electricity consumption (Scope 2) corresponded to 56% of the total; direct emissions (Scope 1) totaled 252,649.063 tCO2e, or 33% of the total. Emissions intensity, in 2020, it was 1.32 t tCO2e per tonne of zinc and zinc oxide sold. Direct biogenic emissions (Scope 1) totaled 168,360.85 tCO2e.

GRI 305-1, 305-2, 305-3, 305-4

6The following gases were included in the calculations: Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O) and Hydrofluorocarbons (HFCs)

7We consider operational control as an approach for calculating

8The emission factors and indices of global warming potential (GWP) used, follow the references of the GHG Protocol

(*) We inform that the energy data (GRI Standarts 302-1, 302-2, 302-3) and greenhouse gas emissions (GRI Standards 305-1, 305-4) indicators have been revised due to the identification of an unintentional error in data compilation from one of our operatings sites. For this reason, the 2020 Annual Report originally issued on Apil 8, 2021 is being reissued to reflect the necessary corrections in the referred indicators (table below). We also clarify that the information reviewed in this Report differs from that presented in the Annual Report of Votorantim S.A., published on April 8, 2021.
GHG Protocol
Três Marias Unit