Abstract
The interaction of carbon materials with molten slags occurs in many pyro-metallurgical processes.
In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic
reduction of MnO-containing silicate slags yields the metal product. In order to study
the interaction of carbon with MnO-containing slags, sessile drop wettability technique is
employed in this study to reduce MnO from a molten slag drop by carbon substrates. The
interfacial area on the carbon substrate before and after reaction with slag is studied by scanning
electron microscope. It is indicated that no Mn metal particles are found at the interface
through the reduction of the MnO slag. Moreover, the reduction of MnO occurs through the
contribution of Boudouard reaction and it causes carbon consumption in particular active sites
at the interface, which generate carbon degradation and open pore growth at the interface. It is
shown that the slag is fragmented to many micro-droplets at the reaction interface, potentially
due to the effect on the interfacial energies of a provisional liquid Mn thin film. The rapid
reduction of these slag micro-droplets affects the carbon surface with making deep micro-pores.
A mechanism for the formation of slag micro-droplets is proposed, which is based on the
formation of provisional micro thin films of liquid Mn at the interface.
In the production of high carbon ferromanganese in submerged arc furnace, the carbothermic
reduction of MnO-containing silicate slags yields the metal product. In order to study
the interaction of carbon with MnO-containing slags, sessile drop wettability technique is
employed in this study to reduce MnO from a molten slag drop by carbon substrates. The
interfacial area on the carbon substrate before and after reaction with slag is studied by scanning
electron microscope. It is indicated that no Mn metal particles are found at the interface
through the reduction of the MnO slag. Moreover, the reduction of MnO occurs through the
contribution of Boudouard reaction and it causes carbon consumption in particular active sites
at the interface, which generate carbon degradation and open pore growth at the interface. It is
shown that the slag is fragmented to many micro-droplets at the reaction interface, potentially
due to the effect on the interfacial energies of a provisional liquid Mn thin film. The rapid
reduction of these slag micro-droplets affects the carbon surface with making deep micro-pores.
A mechanism for the formation of slag micro-droplets is proposed, which is based on the
formation of provisional micro thin films of liquid Mn at the interface.
