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Show 1. It can v~porize, if the temper~ture is sufficiently hig~; 2. It CAn melt and forM a liquid droplet in conjunction with other Metal particles; 93. It can remaln unchanged in its current location. This wlll occur only if the metal i~ in the form of a very high melting refractory oXlde And there is ~ sufficient quantity of the met~l present to forM a stable matri~; 4. It can react ~nd forM a new ~oecies which would then eit~Er melt, vaporize, or remain unchanged. Th~ speCies that vaporize move away from the waste into a cooler more co xy~er : rlch atrncr=phE?re where t~,ey caY', \.\Y,dergcl f\.\r"ther reactic'Y,s cor c ond eYrse. The condensing species form new particles as well as deOoslting C"Y, the- sl.H"'faces of the particles that alre-ac;y Exist. The y.ewly fcorrne-c particles generally are about 0.02 microns in diameter and grow to range in size from 0.02 mlcrons to 1 Micron. This aerosol has consioerably more surface area than the larger particles. Thus, the condensing ~aterial, which tends to deposit evenly on all Available surface area, prefere-ntially depe.sits C"Y. the small pa.,...·ticles. (Ref. 9). This paper focu~es on the vaporization of metals frOM burnin~ wastes. The analysis is based on two SiMplifying assumptions: 1) Thermodynamic equilibrium is maintained, and 2> All elements present in the waste are intimately Mixed. Although these precise conditions are rarely encountered, they close:y app"r coxirnate cCly,diticlr,s fcouy,d iY, a wide raY'ge cof practical lr,clr,era"ticorl systems. Based on the assumptions, a computer progra~ ~evelope~ ~t ~ASA's Lew i s Research Center was used to predict the metal scecies formed ana the state of each species. The program was originally developed by Zeleznik ar,d GcordccY, iY, 19l52 <Ref. 10) ar.d has \.\y.dergcly.e several revisicorls since ti'Clt time. The version used was last revised in 19S5. The followin~ brief description of the program is condensed frc~ reference 11. The program det~rMines the equilibriUM state of a complex chemical sy~tem by minimizing the free energy. All gases are assumed to be ioeal and interactions among phases are neglected. Thus the eauation of state of the rni ~ture is ( 1 ) where P is press\.lre, V specific volume, n Moles, and T teMperature. 6 ./ . --- - .. .. - - .- ... - . .... - .. - - -- - _. |
