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Show C~rbon Hydrog_n BarlUM ChromluM Lead Mercury (DRY, CHLORINE FREE BASIS) 90% 10% 100 100 100 100 (by weight) (by welght) ppM ppm ppm ppm The key par~meters which were .determined to significantly influence metal vaporization are: teMperature, oxygen concentration, chlorine concentration, and metal The impact of temperature on the effective vapor pressure of t~e met~ls is shown in Figure 4. The effective vapor pressure is based on the most stable chemical forms of the metal under the conditions considered._ 4 Mercury is highly volatile and has a vapor pressure much greater than 10 ~tm for all temperatures considered. The effective vapor pressures of leac, barium, and chrOMiUM all increase sharply with teMper~ture. The impact of oxygen concentration, expressed as stoichiometric ratio, on the behavior of barium is shown in Figure 5. The availability of oxygen determines ~pecies forMed and consequently influences the effective va~or pressure. At 1300 K, the vapor pressure of chromium is very sffiall while -~ the vapor pressures of mercury and lead are above 1 x 10 atm. The impact of chlorine concentration is shown in Figure 6. In peneral chlorides ~re more volatile than the corresponding metal oxides or uncombined metals. Thus the effective vapor pre~sure of each metal is increased as the chlorine concentration increases and more of the metal is converted to metal chloride. However, once the metal has been totally converted to metal chloride the presence of additional chlorine has no further effect on the vapor pressure o~ the metal. The effective vapor pressure of barium varies little with chlorine concentr~tion due to the unusually low volatility o~ barium chloride, 6nd high volatility of uncombined barium. Since le~d and mercury are totally vaporized at 1300 K in the absence of chlorine, chlorine has no effect on the effectlve vapor pressures of these metals at this temperature. Chromium'. volatillty rlses r.pidly as the chlorine concentration increases until most o~ the chrOMlum ha5 been converted to the appropriate chromium chlorid • • This application of the equilibrium model indicates that the amount of metal vaporized 9 |