Graded charging process and time series of raw materials for blast furnaces

To counter the condition that quality deterioration of raw materials causes the pressure drop in a blast furnace increasing, new burden charging methods are sought to improve the permeability. Study results show that mixing different size particles can decrease the voidage and thus worsen the permeability, but decreasing the particle mixing can increase the permeability. In order to improve the permeability, the grading patterns, the sequence and period for charging different sizes of raw materials were studied in turn. And also the burden charging characteristics of cascade hoppers, two parallel hoppers, and three parallel hoppers were researched. The study result is very important in decreasing the pressure drop and keeping the BF stability and smooth.