Dams


CSN is also conducting a program to de-characterize existing dams, which even exceeds the requirements established by government agencies, since it also provides for the de-characterization of dams regardless of the construction method. The conduction of the de-characterization projects and the safety management of the structures follow the best national and international practices. Safety management is carried out by a dedicated technical team and monitored by the Dams Committee – composed of technicians and executives from the Company and reporting to the Board of Directors, the National Mining Agency and other competent authorities. 

Between 2020 and 2021, CSN Mineração completed the de-characterization of the B5 Dam (Casa de Pedra) and the Auxiliary do Vigia Dam (Pires Complex). The Vigia Dam is in the process of completing the de-characterization works, with completion scheduled for the year 2023.

The company is at the forefront of mining tailings management worldwide, having invested around R$400 million in technologies that allowed better tailings management with filtration and dry stacking, making our processes 100% since the beginning of 2020. % independent of the use of the tailings dam. All dams are audited by independent companies specialized in the subject, aiming at attesting stability and identifying preventive actions to guarantee this stability. Throughout 2022, all CSN Mineração dams remain stable, that is, without any emergency or alert level, and with all stability declarations issued. Continuing with the de-characterization schedule of our dams, the work on the belt channel of the Vigia Dam was completed and we are in the clear process of de-characterization of this dam, scheduled for completion in 2023.

Dam management aligned with legal requirements

CSN Mineração oriented by Resolution ANM No. 95 of 2022 (National Mining Agency), which regulates the measures applicable to mining dams, carries out the work aimed at the management of its dams.

The PSB (Dam Safety Plan), as defined in the resolution, is an instrument whose main objective is to assist the entrepreneur in ensuring dam safety standards by reducing the risks of accidents and their consequences. The PSB is composed of 6 volumes:

-General information;
-Plans and procedures;
-Records and controls;
-Periodic Dam Safety Review (RPSB);
-Action and emergency plan for mining dams (PAEBM);
-Risk management process (PGRBM).
-Directed by the PSB, the Mine and Dam Geotechnics Management (GMB) carries out the management of its structures through measures that ensure the good conservation status of its dams and the stability of our dams.

Periodically, CSN Mineração reports to the state and federal agencies responsible for dam surveillance, the status of the activities carried out, in order to comply with the legislation. At national level, the information regarding the structures is declared in SIGBM (Integrated System of Management of Mining Dams), and is open to public consultation.

Mining Dams Emergency Action Plan (PAEBM)
Check it out the Dam Emergency Action Plans (PAEBMs) below. To access the annexes of each structure, click here.

Mining Dams Emergency Action Plan (PAEBM)


Casa de Pedra Dam

Casa de Pedra Dam
Volume V – Emergency Action Plan - PAEBM

Lagarto Dam

Lagarto Dam
Volume V – Emergency Action Plan - PAEBM

Engenho Dike

Engenho Dike
Volume V – Emergency Action Plan - PAEBM

Esmeril Dike

Esmeril Dike
Volume V – Emergency Action Plan - PAEBM

B2 Dam

B2 Dam
Volume V – Emergency Action Plan - PAEBM

B2A Dam

B2A Dam
Volume V – Emergency Action Plan - PAEBM

Ecológica Dam

Ecológica Dam
Volume V – Emergency Action Plan - PAEBM

Vigia Dam

Vigia Dam
Volume V – Emergency Action Plan - PAEBM

Bichento IIIA Dike

Bichento IIIA Dike
Volume V – Emergency Action Plan - PAEBM

B4 Dam

B4 Dam
Volume V – Emergency Action Plan - PAEBM

Since 2020, 100% of iron ore tailings are filtered and dry stacked at CSN Mineração


As barragens construídas pelo método a montante estão em franco processo de descomissionamento. A segurança e o monitoramento das estruturas são feitos por engenheiros e técnicos em geotécnica de barragens. Estamos investindo na independência gradual das barragens e foco na segurança e sustentabilidade do negócio, com a melhor interface com a comunidade do entorno, trazendo o equilíbrio operacional para todos. Nesse sentido, os principais projetos são:

Tailings Filtration Plant I and II


  • Greater filters in the iron ore segment;
  • Reduce dependence on dams;
  • Dry stacking of tailings;
  • Higher production rate at the central plant.

Magnetic Concentration Plant that reduces the volume of tailings, CMAI and CMAI II:


  • Reduce dependence on dams;
  • Transform part of the tailings into a product;
  • Allow scale gain;
  • Improve ore quality.
So far, dams B1 and B2 – Água Preta, in Lafaiete (CSN); B5, in Congonhas (CMIN), ecological 2, in Rio Acima (MIPE) and Auxília do Vigia in Pires complex (CMIN).

CSN Mineração dam de-characterization schedule for the coming years


Magnetic Concentration Plant that reduces the volume of tailings, CMAI and CMAI II:


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