PURPOSE: To maintain a proper degree of reduction in a blast furnace for simultaneously smelting zinc and lead by measuring the oxygen potential in discharged slag when molten metal is discharged and by changing the value C/Zn in starting materials to be charged using the measured value as a controlling factor.
CONSTITUTION: Whenever molten metal is discharged from a blast furnace for simultaneously smelting zinc and lead, the oxygen potential in slag discharged in a predetermined time during the discharge of the molten metal is measured. When the measured value is continuously different from the desired value by a fixed value or more by a predetermined number of repetitions, the weight ratio of C/Zn in starting materials to be charged into the furnace is changed in accordance with a prearranged standard. The degree of reduction in the furnace is controlled so as to bring the oxygen potential close to the desired value. By this method the amount of Zn in discharged slag is reduced and the amount of coke can be saved.
KUSUHASHI HIROSHI
IKEDA KAZUO
Next Patent: METHOD FOR TAPPING MOLTEN METAL FROM SIMULTANEOUS SMELTING FURNACE FOR ZINC AND LEAD