Foaming Behavior in Molten Slag Caused by Decomposition of Carbonate Minerals

The average foam life is proposed as an index to the foaming behavior in molten slag. The molten slag system of Na_2B_4O_7-CaO-MgO is foamed by the gas from the thermal decomposition of carbonate minerals as the foamer. The experimental results show that foamer type and particle size have influence upon the average foam life of slag. The concentration of CaO and MgO in molten slag not only varies the physical properties of melt but also influences directly the decomposition rate of carbonate and the bubble size of gas, thus playing an important role in foaming and to foam stability of slag.