Treatment of dust from electric arc furnaces

Recycling of electric steel dust when sintering iron ore to eliminate zinc.

The main objective of this work is to recycle the electric steel dust in the sintering of iron ore, through the pre-agglomeration (micropelletization) of the waste together with coke, aiming at the elimination of zinc in the process. In Figure 1, it is possible to observe the main methodology applied at work and the raw materials involved.

In the tests in which the micropellets composed of electric steel dust were added to the mixture to be sintered, the sintering machine was filled in 3 layers (Figure 2). After sintering, samples were taken from 3 points of the sinter cake (top, middle and bottom). Then the material was sent for analysis in the Scanning Electron Microscope (SEM).

The results obtained by MEV indicate that the sinter cake presents a variation in its composition. The Figure 3 shows the micrographs.

The Zn content in the samples varied, however more tests should be done to check the level of variation of this element after sintering. These tests consist of chemical analysis and some more analysis under the microscope. In addition, another type of ore from Arcelor Mittal in Tubarão – ES is being studied in the sintering process.