Gas-phase resistance to the vaporization of mercuric halides in high-temperature atmospheric gaseous condition

Gas-phase resistances to the vaporization of three mercury halides into atmosphere at elevated temperatures were evaluated. Lab-scale vaporization experiments for mercuric bromide, mercuric iodide and mercuric chloride were performed and the results were analyzed to evaluate gas-phase resistance to vaporization of three mercuric halides using the vaporization and condensation model. Overall mass transfer coefficients, K-G for the sample mercuric halides, were in the range between 4.8 x 10(-6) and 1.6 x 10(-5) g-mole sec(-1) cm(-2) atm(-1) at the temperatures from the subliming to boiling temperatures and were much smaller than interfacial mass transfer coefficients, k(i). It was estimated that resistance of pure gasphase mass transfer is much larger than that of the phase transition between condensed and gas phases. It could be therefore said that gas-phase mass transfer coefficients, k(G) for mercuric halides, were nearly equal to overall mass transfer coefficient, K-G which could be determined as a function of temperatures.