VISCOSITY CHANGE OF ACID AND BASIC OPEN HEARTH SLAGS DURING THE REFINING PERIOD

The writer investigated the viscosity change of acid and basic open-hearth slags during the refining period, with measuring apparatus for viscosity based on the rotating cylinder method. In the oxidation period the viscosity of the slag is small because of the addition of metallic oxides, such as iron ore, scale, and fluorspar. But in the equilibrium period the viscosity of the slag becomes gradually thicker by increasing the concentration of acidity or basicity, the acid or basic contents being absorbed from furnace banks.