Planejamento de portos graneleiros para atender a produção de usina pelotizadora considerando designação de áreas de pátio e fila de navios

Abstract

One of main raw materials of steel industry is the iron ore pellet which is produced in pelletizing process. Due to its physic-chemical properties, the pellets are used mainly at blast furnace feeding, bringing a higher efficiency in steel production process. The iron ore pellets are produced in batches in a continuous process, and are stored at the bulk port „s stockyard until the times that are loaded into vessels to be delivered to customers. In case of lack of storage area availability, the pelletizing production must be discontinued, generating considerable financial impacts. Thus, the pelletizing planners must plan which stockyard and the position of each batch focusing in have sufficient area to store the pellets lots planned to be produced. At same time, they have to plan the lineup of vessels that will arrive at port and that will withdraw the batches from stockyard allowing areas be released for new batches storage. The objective is always to minimize eventual production stoppages due to lack of storage area. The well-known information by planners is the batches production planning date and vessels estimated time of arrival. For the location planning of cargoes at the stockyard, it is discussed at the literature the nominated Yard Assignment Problem (YAP). Considering the planning of vessels berthing sequencing, it is proposed the berth allocation problem (BAP). Although the wide number of BAP published studies, there is a scarcity of studies that discuss the BAP for bulk ports e even less studies integrating the BAP with YAP for pellets bulk ports. Furthermore, it is important to highlight that most of studies that discuss both problems combined has the focus on vessel quay and in reduce vessels permanence time at port. Unlikely of the others, this study has the objective of minimize the nonattendance of pellets batches production plan, in other words, reduce the time between the planned production time and the time the stockyard was used to receive the pellets batch, as well the time of vessels stay at port. To solve this problem is proposed a mathematical model to define the location of each pellets batch at stockyard in an integrated way to the vessels quay planning aiming to attend the pelletizing production plan and avoid eventual production stoppage due to lack of stockyard area. This study can be applied to other pelletizing companies in the worldwide that have different configurations in their own stockyards and quays. The obtained results indicate that the model has high applicability and can be used as a decision tool at the planning process of pellets production allocation at the stockyard