Circular Economy
and Waste

Sustainability: a priority in our way of operating

Sustainability has been a strategic topic since the establishment of Nexa and has always guided our business in all aspects. This means special attention to the management of waste and tailings resulting from the activities and their constant improvement to increasingly mitigate and reduce our socio-environmental impacts.

We invest in the development of innovative technologies aimed at the reuse of tailings and waste and we have three different ways of disposing them: return to the mine (backfill), dry stacking and, finally, we dispose of the materials in dams.

Currently, only 15% of the tailings and waste generated by us in Brazil and Peru are disposed of in dams.

In line with the transparency principles and aiming to maintain effective communication with our stakeholders,we have a specific page on Dams and Deposits.

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Circular Economy and Waste

In our strategy of prioritizing alternatives to reduce the generation of mining and smelter tailings, and in compliance with local legislation, we also use this waste in byproducts to avoid its disposal and reduce environmental liabilities. Circular economy initiatives such as this one offer new uses to materials and support our goal of continually reducing the impact of our activities on the environment.

Our management

As part of our continuous improvement process, we adopted a management platform that allowed us to improve performance and unify our database for more assertive information management.

The system, which has already been deployed in all units in Brazil and is currently being tested in Cajamarquilla, Peru, automatically generates the full waste lifecycle – generation, storage, processing and final disposal. For this, it considers the environmental regulations in force in both countries, as well as the main market practices.

Another differential for our operation is that the teams rely on engineering projects and on MiningLab, our innovation platform. Through it, we seek to develop new technologies that allow us to reduce our volumes of waste and adopt the principles of the circular economy to transform them into secondary products for trading.

Get to know our initiatives

As a result of our investments in Research and Innovation, we have relevant projects being implemented at our units in Brazil and Peru.

Circular Economy in Morro Agudo

Circular Economy in Morro Agudo

We transform all the tailings generated in the operation into a secondary product – agricultural limestone dust, which gives rise to Zincal200, a product used in agriculture to reduce soil acidity and increase productivity. After sedimentation, part of the tailings is reused in the plant and another is sold as Zincal. In 2020, we reached record sales of Zincal, which allowed us to reduce the volume of old tailings stored. In 2021, we surpassed 1.3 million tons of limestone sold and doubled the reprocessing of old waste at the plant.

Iron Concentrate in Vazante Project

Iron Concentrate in Vazante Project

The project’s purpose is to generate revenue from the transformation of waste into iron concentrate (10% of its composition), thus reducing the volume of material disposed of in stacks. There is currently a test plant for the progress of this project.

Synthetic Granite in Três Marias

Synthetic Granite in Três Marias

After the commissioning of the pilot plant for the production of glass-ceramic material installed at Senai Cimatec, experiments began to produce glass pieces from the waste generated in the belt filter at the Três Marias unit. The three types of materials produced by the experiment were classified as inert waste. The project will move to industrial testing in 2022.

Recycling of Batteries

Recycling of Batteries

Green Electron, Nexa’s partner recycling company, collects discarded batteries at several collection points throughout Brazil and sends them to Nexa for mining processing. At the Juiz de Fora/MG plant, the piles are initially crushed and blended with other secondary raw materials and later fed into the Waelz Rotary Furnace using German technology. In the furnace, the metals are released in the form of oxides, which are sent to various production lines.

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Our aspiration

We aspire to be a global benchmark in the value creation with the resources that we mine and that originate from our production process or from partners.

Check our indicators

Materials used by weight or volume
Correlated indicators
GRI Dimension:
Environmental
GRI Code:
301-1
SDG
Materials used by weight or volume
Classification 2019 2020 2021
ROM (Internal Supply) Non Renewable 12.984.367 10.656.539 12.216.550
Concentrates (Internal Supply) 1.230.367 1.192.832 1.258.656
Other Materials (External Supply) 88.708 105.528 188.838
Other Materials (Internal Delivery) 317.529 323.010 278.301
Total volume of main resources 14.620.971 12.278.909  13.942.345

 

Recycled input materials
Correlated indicators
GRI Dimension:
Environmental
GRI Code:
301-2
SDG
Recycled input materials
2019 2020 2021
Total of recycled materials used 85.464 85.291 3.570.052
Total of materials used 14.620.971 12.278.909 13.942.345
Percentage of recycled materials used 1% 1% 26%

 

Waste generated
Correlated indicators
GRI Dimension:
Waste
GRI Code:
306-3
Sector SASB:
Mining and Metals
SASB Dimension:
Waste and Hazardous Materials Management
SASB Code:
EM-MM-150 a.1
SASB Code:
EM-MM-150 a.2
SDG
Volume of Waste (thousand tons) and Recycled Percentage
Hazardous 2019 2020 2021
Mineral-metallurgical waste (sterile) 8.749,86 6.744,80 9.497,91
Mineral-metallurgical waste that was recycled, reused or remanufactured (sterile) N/A N/A 1.485,70
(16%)
Mineral-metallurgical waste (reject) 10.172,39 9.126,08 9.928,30
Mineral-metallurgical waste that was recycled, reused or remanufactured (tailings) N/A N/A 5.048,40
(51%)
Industrial waste 5,24 5,9 7,58
Non Hazardous Mini-metallurgical waste (sterile) 1.010,03 2.207,74 1.181,16
Miner-metallurgical waste that was recycled, reused or remanufactured (sterile) N/A N/A 801,36
(68%)
Mini-metallurgical waste (tailings) 1.043,04 1.245,45 1.265,73
Mini-metallurgical waste that has been recycled, reused or remanufactured (tailings) N/A N/A 156,58
(12%)
Industrial waste 104,65 133,52 26,34

 

Total Weight of Waste, per type and disposal method (tons)
2019 2020 2021
Disposal of non-hazardous waste 104.657,85 133.521,19 26.338,36
Composting 1.405,82 1.399,75 1.864,12
Reuse/recycling 99.218,64 124.615,23 18.456,59**
Recovery
Incineration (or use as fuel) 262,87 777,95
Sanitary landfill 1.934,22 2.092,68 2.435,27
Co-processing/refinery 208,53 169,68 1.511,47
On-site storage 1.530,99 3.904,63 0,01
Industrial landfill 42,05 135,85 575,57
Other 54,73 1.203,37 717,38
Hazardous Waste Disposal 5.240,78 5.899,75 7.582,32
Composting
Reuse/recycling 294 379,1 1.605,84*
Recovery 0,64 0,5 0,32
Incineration (or use as fuel) 0,39 1,3 68,86
Industrial landfill 2.633,63 2.760,06 2.741,41
Co-processing/refinery 1.912,86 2.408,94 2.866,92
On-site storage 259,07 301,56
Disposal for specific purposes 2,38 4,13 0,45
Sale – partial recycling 137,56
Other 0,24 44,16 298,53
Total Waste Disposal 109.898,63 139.420,94 33.920,67
Composting 1.405,82 1.399,75 1.864,12
Reuse/recycling 99.512,54 124.994,33 20.062,42
Recovery 0,64 0,5 0,32
Incineration (or use as fuel) 263,26 1,3 846,81
Sanitary landfill 1.934,22 2.092,68 2.435,27
Industrial landfill 2.633,63 2.895,91 3.316,98
Co-processing/refinery 2.121,39 2.578,62 4.378,40
On-site storage 1.790,06 4.206,19 0,01
Disposal for specific purposes 2,38 4,13 0,45
Sale – partial recycling 137,56
Others 54,97 1.247,53 1.015,90

* Increase in recycling projects in Peru and mobilization of cleanup areas in Vazante (Brazil).

** Reduction of recycled waste due to categorization of Waelz aggregate as a by-product in 2021.

N/A: Data not reported for the period

Total amounts of overburden, rock, tailings and sludges and their associated risks
Correlated indicators
GRI Dimension:
Environmental
GRI Code:
MM3
Sector SASB:
Mining and Metals
SASB Dimension:
Waste and Hazardous Materials Management
SASB Code:
EM-MM-150 a.1
SASB Code:
EM-MM-150 a.2
Volume of Waste (thousand tons) and Recycled Percentage
Hazardous 2019 2020 2021
Miner-metallurgical waste (sterile) 8.749,86 6.744,80 9.497,91
Mineral-metallurgical waste that has been recycled, reused or remanufactured (sterile) N/A N/A 1.485,70
(16%)
Mini-metallurgical waste (tailings) 10.172,39 9.126,08 9.928,30
Mini-metallurgical waste that has been recycled, reused or remanufactured (tailings) N/A N/A 5.048,40
(51%)
Industrial waste 5,24 5,9 7,58
Non-hazardous Miner-metallurgical waste (sterile) 1.010,03 2.207,74 1.181,16
Mineral-metallurgical waste that has been recycled, reused or remanufactured (sterile) N/A N/A 801,36
(68%)
Mini-metallurgical waste (tailings) 1.043,04 1.245,45 1.265,73
Mini-metallurgical waste that has been recycled, reused or remanufactured (tailings) N/A N/A 156,58
(12%)
Industrial waste 104,65 133,52 26,34

N/A: Data not reported for the period

 

Our contribution to the SDGs

SDGs related to the topic:

 

In 2017, we signed a commitment to the global agenda consisting of 17 goals and 169 targets to be achieved by 2030.

SDGs related to the topic:

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Read more about Nexa in the links below

Strategy

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Biodiversity and Land Use

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Use and Disposal of Water

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Climate Change

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Dams Management

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Decommissioning

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