Dry Processing

About Vale

Dry Processing

Dry Iron Ore Processing

Dry processing at Vale

In the last 10 years, Vale invested almost R$66 billion in facilities and development of technologies for the dry iron ore processing production. Today, most of our iron ore production (about 60%) is through dry processing.

The natural moisture processing is used at Carajás and Serra Leste mines, at S11D Eliezer Batista complex, in Pará, and at several plants in Minas Gerais. 

In five years, the company's goal is 70%, with R$11 billion of investments.

North System

200 metrictonc im 2018 - 80% of the production
through dry processing

Pará

100% im 2024

Minas Gerais

from 20% im 2016 to
32% im 2018

In Brasil

2014
2018
2024

Benefits

What are
the benefits
of the dry
processing?

Sustainability:

For the dry treatment, no water (from the environment) is required to process the extracted ore; thus, there is no need to build tailings dams. In comparison to the wet processing, the dry processing technique reduces the total water consumption by 93%, on average.

Productivity and Safety:

Productivity increases due to greater resource savings, lower power consumption, fewer production phases, fewer equipment, and a simpler and safer operation.

No Waste:

In the wet processing, there is loss of material, which is directed to the tailings dams. In the dry processing, 100% of the iron ore is processed and commercialized.

Learn more about
dry processing

How does it work?

Before commercialization, the extracted iron is crushed into small pieces and classified according to the rock sizes. In this process, the ore is screened through screens, where the separation is made according to a standard product specification. The size classification by screening is one of the most important phases of production.

During the wet processing, water is used to classify and purify the iron ore, removing impurities (such as silica) that affect the final product quality.

Then, material must be exposed to moisture reduction processes in order to be stacked and transported to the clients. This processing route is used for the ore that has low iron content.

During the dry treatment, no water is added and, after crushing and screening, the ore is ready for the market.

Types of ore processing

The run of mine (ROM) processing can be done by two different methods – the wet and the dry processing.

Wet Processing

After the wet processing, the muddy sludge
produced at the mine is known as tailings.
This waste is disposed of in dams.

Dry Processing

This natural moisture processing without water
does not generate tailings, so no dam is required.

Study of solutions

Vale continues to study different solutions and technologies for ore processing. Check out some of them below.

Dry stacking

To reduce the use of dams, Vale plans to invest almost R$1.5 billion (US$390 million) for implementation of dry tailings stacking technology in Minas Gerais between 2020 and 2023. The technique allows filtering and reusing water from the tailings so that tailings can be stacked, thus reducing the use of dams.

In 2011, the company developed a pilot project at Cianita stack, in Vargem Grande, with R$100 million of investments.

Dry magnetic concentration

Another solution that has been studied is the dry magnetic concentration of iron ore based on the technology developed by New Steel, a company acquired by Vale at the end of 2018.

This technology eliminates the use of water in the process of concentrating the low iron content ore, which allows the tailings to be disposed of in piles as waste rock, similar to the process used in dry stacking. This process is still under industrial development.

Glossary

To understand the ore processing and check other definitions related to dams, access the glossary

Click here to acess

Dams

To learn more about dams
acess the dams page

Learn more about Vale dams
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