Under the situation of raw material's quality not being guaranteed in 4# blast furnace of Han Steel,its steady condition and smooth running and high-efficiency production are realized with operation parameters being continuously optimized and low-silicon smelting adopted,and its highest operating rate reaches 2.

The intensification of blast furnace operation is based on quality raw materials and smooth running are put forward.

The cause of clogging on furnace wall and instable running of BF is the relatively great fluctuation of water temperature difference above the middle of bosh.

By implementation of Ca-treatment in the secondary refining instead of Re wire feeding into the CC mould the ratio of smooth operation in refining SM490A has been greatly raised and the elongation of the steel increased by 12% and perfect good cold bending achieved.