SEPARATION OF METAL DROPLETS FROM SLAG

The motion of liquid metal droplets in molten slags was studied using low temperature physical modeling and X-ray observations at high tempe ratures. Experiments were done to assess settling times of metal dropl ets in slags. Experimental work included oil and water modeling and hi gh temperature experiments utilizing a furnace equipped with an X-ray fluoroscopy apparatus. Results show that settling times of metal dropl ets in stagnant slags and water droplets in a variety of oils can be a ccurately predicted utilizing Stokes' equation modified for the approp riate experimental conditions. It was also found that gas stirring in slags, whether by chemical reaction or gas injection, and slag foaming increases droplet settling times. Stable foams resulting from the rea ction of FeO in the slag and carbon in the metal as well as gas inject ion in the metal phase caused rafts to form which could permanently ho ld droplets up to about 5 mm in diameter at the top of the slag. For b etter separation, slags with low viscosities are recommended and foami ng should be avoided.