Electrical charge of metal oxides in liquid metals

An attempt was made to determine the electrical charging characteristics of metal oxide particles suspended in a liquid metal. A liquid metal and metal oxide particles in the liquid were respectively chosen as a cathode and anode for the potential measurements. By taking a close symmetry of electrical circuit, the potential difference between electrodes could be measured successfully. Experimental results show that alumina carries a positive charge by providing electrons to the liquid metal phase such as molten lead and molten aluminum. The potential difference was in the range of 0.01 and 0.08 mV, and was increased with increasing temperature and the amount of oxide added to the liquid metal. Most metal oxides in liquid metal carry a positive charge owing to the formation of the space-diffused charge layer.