To improve the mass production process of both low-phosphorus and conventional-grade steels more economically, a new refining process, called SRP ( Simple Refining Process), has been developed at Kashima Steel Works. In this process, two 250t capacity top and bottom blown converters are used as reactors, namely one dephosphorization furnace and one decarburization furnace. Low P2O5-content lumpy slag, obtained from the decarburization furnace, is used as a dephosphorization agent in the dephosphorization furnace, minimizing total lime consumption and achieving stable and quick refining. In addition, scrap can be used in the dephosphorization furnace due to bottom blowing. On the other hand, by the reduction of slag volume in the decarburization furnace, manganese ore can be effectively smelted. Therefore manganese alloy consumption can be reduced. SRP made it possible not only to produce extra low phosphorus steels but also reduce the total cost of the steel-making process.
