CBA completes waste drying plant, which cost R$500 million

The Companhia Brasileira de Alumínio (CBA) begins the operation of a filtration system by the end of April, consisting of 3 filter presses, for drying waste from its alumina plant located in Alumínio (SP), which generates 1,500 t/day of waste. With this, the company will be able to completely do without a dam for wet tailings storage. 

According to Luciano Alves, CEO of the company, the project has involved investments of R$420 million so far, but the total, considering what will be invested in the future, should reach around R$500 million.

The filtration system, which was imported, is a technology already approved on the market and the objective is to have a safer operation, as the disposal is now done dry and no longer wet. In fact, as Luciano Alves explains, CBA had already been drying the dam for a few years, not only thinking about starting up the waste filtration system project, but also because, by reusing the liquid material from the dam, it is possible to reuse part of the raw materials in alumina plant. To date, 81 per cent of the wet waste contained in the dam has been removed, which is now prepared to receive dry waste.

According to Leandro Faria, general manager of Sustainability at CBA, in addition to the environmental benefit, there is an economic benefit, because the liquids contained in the dam are reused, as is the case with caustic soda, used in the alumina production process. Another benefit of the project is that it allows the useful life of the dam to be extended. 

“So, a dam that would be close to the end of its useful life will have another 20 years to go. What was a dam becomes an area for the deposition of dry waste. And it has the benefit of being able to use the dry residue in other industries, such as the cement industry”, 

he says.  

According to the CEO, the project is part of a larger CBA future growth strategy, with a portfolio of projects totaling approximately R$2.5 billion and which includes alumina, furnace room, recycling and other parts of the process, in which The concept of no longer using tailings dams is included.

“There are other projects related to this, such as mobile processing, which is still on an R&D scale, in which the ore is processed at the mining front, returning the residue to the pit itself, without the need for a dam.”

He explains that two years ago the company started operating Room 3, in the aluminium production unit, and has an investment to be made to resume the operation of Room 1, adding another 50 thousand tons to production capacity. This project is scheduled to start up in 2027.