Brazil for the Environment

ABOUT IT

In 2024, CBA inaugurated a waste processing system at its Alumina Refinery using three filter presses. This project aims to replace the traditional wet disposal method with a dry disposal process, using the same dam in an innovative way.
The project development took place when over the last 10 years, including in-depth studies on waste stacking, removal and reuse of water accumulated in the dam, and tests with a pilot filter capable of processing 10 tons per hour.
The newly opened filter presses have capacity of 110 tons per hour and concentrate the waste before its disposal in the Palmital dam, located in Alumínio (SP), increasing the solids content from 45% to 75%. Each filter has 207 plates measuring 2.5m x 2.5m each, and the plant also has 10 compressors and 6 conveyor belts for transporting the pressed material. Thus, waste disposal is now done dry, making the system even safer.
In the environmental context, technology increases the efficiency of waste treatment., This allows for more effective management and extends the dam's lifespan by approximately 20 years. This extension gives the Company more time to plan and implement its strategies for reusing the waste in other processes, avoiding the need to impact a new area.
The company has already patented studies for the use of the dried material as a co-product, for example in the manufacture of pozzolanic cement.
To enable the stacking of waste in the current dam, it was necessary to remove a large part of the volume of liquids accumulated in it, allowing for water recirculation and the recovery of caustic soda in the refinery process.
The project aligns with CBA's ESG 2030 Strategy, which includes the goal of eliminating waste disposal in dams.

Results and Objectives

From 2017 to 2024, more than 1.8 million cubic meters of water (approximately 720 Olympic-sized swimming pools) and 27,000 tons of caustic soda were reused, avoiding the purchase of supplies and making more water available to society. With the start of operation of the filters, the liquids removed from the waste continue to be reused in the process.

The filter presses became operational at the end of the first half of 2024 and are undergoing operational adjustments to reach their maximum capacities. This is expected to eliminate the need for wet disposal of the residue, allowing for complete water recirculation and reuse of caustic soda. Dry disposal increases the dam's safety and avoids impacting new areas for the disposal of these residues. Furthermore, studies are underway for reuse in other industries, such as in civil construction for the manufacture of pozzolanic cement.

Of 2017 to 2024, more than 1.8 billion liters of water were reused. to dry the dam. Annually, the volume of 70 million liters will be reused..

With the elimination of the liquid fraction, 70,000 tons of material will no longer be sent to the dam annually. With the dry residue, CBA is also advancing in industrial-scale studies for the reuse of the material in the manufacture of pozzolanic cement, with the potential to utilize 100% of the volume generated, which totals approximately 500,000 tons per year.

By 2030, CBA aims to eliminate the disposal of waste in dams.

SDGs

External Certification

No

International Commitments

National Commitments

National Solid Waste Policy (PNRS)

More info

Dry waste disposal

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