STUDIES OF METAL-WATER REACTIONS AT HIGH TEMPERATURES: I. THE CONDENSER DISCHARGE EXPERIMENT: PRELIMINARY RESULTS WITH ZIRCONIUM

The condenser-discharge method of conducting molten metal- water reactions at high temperatures was refined. Two methods to measure energy input to specimen wires and, therefore, to compute initial metal temperatures were developed. Calculated metal temperatures were estimated to be accurate to within 100 deg C. Two reaction cells were designed, one for operation at atmospheric pressure with water at room temperature, and the other for operation at high pressure and with water at elevated temperature. Means were developed to determine the surface area of metal exposed to reaction and to determine the total extent of reaction. Pressure transducers were used to record the rate of reactions. The zirconium- water reaction was studied with initial metal temperatures from 1100 to 4000 deg C with 30 and 60-mil wires in room-temperature water. Initial pressures in these runs were the vapor pressures of water at room temperature (20-30 mm). Runs were made with 60-mil wires in water heated to 200 deg C (225 psi). Results in room-temperature water indicated that the reaction became explosive at an initial metal temperature of 2600 deg C. Below this temperature, 20% or less reaction occurred. At higher water temperatures, reaction ranged from 40 to 70%. Runs in heated water showed markedly greater reaction, reaching 50% for fully melted metal at the melting point (1840 deg C). Results suggested that the rates of both solid-state processes and the diffusion of water vapor through the hydrogen blanket surrounding reacting particles must be considered. (auth