Avaliação da aplicação de resíduo agroindustrial como agente aglomerante na fabricação de briquetes de pó de despoeiramento secundário do convertedor LD

Abstract

Agglomerations process in the iron and steelmaking need each time more improvement for allowed that the finest particles of ore or coproducts could be processed by a cheaper and more productive way. Because of that, these agglomerations process, sintering, pelletizing and briquetting have a common target a development of new binders. One of the sturdiest coproducts is the BOF/LD dust, which is usually recycled by sintering route or, less commonly by briquetting and recharged at BOF process or even charged into Blast Furnace. Applying the ESP dust from LD to the briquetting/BOF route is possible recovering other elements once the ESP dust become richer of that element over the time. However, the briquettes need to be strength enough to be transported, stacked, handled, fed and reacted at LD and do not crack and generating fines particles, once it is decreasing the yield and increasing the particles amount of ESP. One of the reasons of that is the lack of a better binder. On another hand, a possible binder is from a coproduct of the cashew nut agribusiness, and it is the cashew nutshell liquid (CNSL). The CNSL has a history of appliance as binder into another process. Therefore, it will briquette and comparing ESP dust from LD using both CNSL as proposed binder and a reference ligand as binder. As reference ligand it will be used the mixture between cement and sugar molasses. Firstly, an exploited phase was conducted where the briquettes was submitted at drop test. It was observed that briquettes using 2% of the proposed binder was as resistance as the briquettes using 6% of molasses and 2% of cement as reference binder. At that phase, it was realized that the briquette resistance is influenced by the kind of dust, binder content, healing time, pos treatment temperature and content of other inorganic binder as lime. In the next phase, it was conducted tests of compression, tumbler index and water resistance to validate the optimized conditions obtained before. All kind of test showed that is possible establish conditions which the proposed ligand outperforms the reference ligand.