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One of the main difficulties in the operation of trough and runners at Arcelor Mittal Tubarão (AMT) Blast-furnace no.02 is the reduced amount of time available for repair procedures. The consequence is that the castable installation must often be performed during hot conditions and the installed castable could easily detach from the base material during the early stage of operation, exposing the previously oxidized base material to molten iron and corrosive slag attack. When events like this happen, emergency repairs must be executed, resulting in increased refractory unit consumption and an unplanned shutdown of unit operation. Considering these targets, Nippon Crucible Co. and Saint-Gobain HPR Brazil have developed a highperformance Al2O3-SiC-C composition based on an entirely novel anti-oxidation technology. Oxidizing reactions could be attenuated by adding an oxidant inhibitor and a water reducing agent. As a result, the open porosity was significantly reduced, resulting in an improvement of campaign life in terms of pig iron throughput when compared with the regular castable. An analysis of this life improvement showed successful results for the material after 250 days of campaign. The main reason for such successful results was that the deterioration caused by the oxidation was significantly less and that this change made on the high cohesive structure of the base material was maintained for a long time. The attained results allowed Arcelor Mittal Tubarão to achieve longer trough campaigns, and avoid any unplanned stoppages with zero breakdown risks. novel castable could achieve an outstanding oxidation resistance by adding the oxidant inhibitor to the dense structure, which led to an extended campaign life during field trials. With S25 NG entirely implemented, BF#02 was able to operate with reduced risks and a very stable production plan, which directly impacted on the productivity level and on the furnace lining preservation 72º Congresso Anual da ABM Anais do Congresso Anual da ABM

Resumo Aços IF (Interstitial Free), são definidos como ultra-baixo-carbono, o que confere propriedades mecânicas especificas para uma série de aplicações, principalmente durante a conformação mecânica, essencial para a indústria automotiva. Os principais materiais refratários utilizados em panelas de aço são baseados em Magnésia-Carbono e Alumina-Magnésia-Carbono, ou seja, apresentam carbono em sua composição. O carbono confere propriedades importantes para os refratários quanto a resistência a corrosão química e melhoria das propriedades termomecânicas. Entretanto, o carbono ao ser incorporado ao aço, no que se define como fenômeno de pick up de carbono, prejudica suas propriedades mecânicas. Além disto, a presença do carbono no revestimento refratário aumenta a perda térmica da panela de aço, desfavorecendo o balanço energético da Aciaria. Este trabalho desenvolveu um modelo químico do pick up de carbono, compreendendo todos os fenômenos envolvidos, bem como obteve-se um modelo térmico transiente avaliando as perdas térmicas de uma panela com e sem carbono. Palavras-chave: Aços IF; Refratários Isentos de Carbono; Pickup de Carbono e Perda Térmica.