In many pyrometallurgical applications, subprocesses such as emulsification, droplet, bubble or jet formation, coalescence, and surfactant adsorption occur at small time scales (typically milliseconds to fractions of seconds), both at slag/metal and slag/gas interfaces. These phenomena are surface tension driven and-due to the high-temperature environment-very difficult to investigate in a quantitative manner. Under these dynamic conditions, the instantaneous surface tension of slags may vary in time as well as along its surface and may change dramatically the rate of the involved processes. This paper presents a new high-temperature experimental setup to study and measure the dynamic surface tension of slags, the mechanisms of slag jet and droplet formation, and the capillary breakup of molten slag jets. It features a three zone furnace with optical access, and a droplet generation device incorporating a back-pressure system in combination with a stopper for precise slag flow control. The first successful results of controlled formation of calcia/alumina droplets and coherent jets in an argon environment are discussed. Various time-dependent phenomena such as droplet formation and elongation, necking, breakup, oscillation, satellite formation, and jet disintegration were investigated and quantified using a high-speed camera system. A dynamic pendant drop method was applied to determine the surface tension. The obtained values are in excellent agreement with literature data.