Diagrams showing equilibrium potentials ( relative to the standard chlorine electrode) plotted vs the negative logarithms of oxide-ion activity (pO(2-)) have been constructed for titanium species including oxides, chlorides, and metal, in molten calcium chloride over the temperature range 800-1100 degrees C. The utility of such diagrams is particularly evident in the field of the molten salt extractive metallurgy of titanium via recently developed electrochemical processing methods. These plots suggest ideal process routes that produce low-oxygen titanium under controlled melt composition and potential. (c) 2005 The Electrochemical Society.