Per: Francisco Junior Batista Pedrosa (Ipt - Instituto de pesquisas tecnológicas), Eric Augustin (Instituto de pesquisas tecnológicas ), Tayná Cunha Souza (Instituto de pesquisas tecnológicas ), Sandra Lúcia de Moraes (Instituto de pesquisas tecnológicas ), André Luiz Nunis da Silva (Instituto de pesquisas tecnológicas ), Fabrício Parreira (vALE), Flávio Dutra (vALE), Valdirene Resende (vALE), Felipe Pimenta (Vale)
Abstract:
Iron ore agglomerates are fundamentals in the use of low-grade iron ore deposits and in the decarbonization journey of the steel industry, as they are “engineered” products in terms of chemical composition, shape and mechanical resistance. Although chemical composition is the key factor in the performance of reduction reactors, mechanical strength is a prerequisite, especially when dealing with agglomerates destined for the transoceanic market. As transport, handling and arrangement in piles or beds involve different efforts, it is of fundamental importance to carry out characterization tests that simulate, in the best possible way, these efforts. Iron ore agglomerates are conventionally characterized by standardized tests that evaluate resistance to compression, abrasion (tumbling) and impact (Shatter). The traditional Shatter test is carried out on sinters, following a procedure that evaluates the degradation of the product after 4 successive drops. However, in general, carrying out 4 drops in agglomerates of high mechanical resistance (pellets and briquettes) is not sufficient to discretize the performance of products produced from different mixtures and/or production methods. In view of this, an alternative method was developed, called Stressed Shatter, which consists of recording the number of falls that the cluster supports to reach a Shatter index of 85%. This test, which has been conducted manually, can now be conducted on an Automatic Shatter. The results of the Stressed Shatter tests conducted on manual and automatic equipment are relatively similar, with a difference of 3%. The assays were performed in duplicate and demonstrated excellent reproducibility. Another point observed is that the mass of the agglomerate has a significant influence on impact resistance. The results presented in the present study enable Automatic Shatter as a method for characterizing agglomerates with the advantage of reducing labor and minimizing the risk of accidents. Such equipment and method can be used in R&D centers, in addition to quality control of processes and products in the mining and steel industries.
