Sublimation of metals

A similar type of catalyst including a supported noble metal for regeneration was described extensively in a series of patents assigned to UOP (209-214). The catalysts were prepared by the sublimation of metal halides, especially aluminum chloride and boron trifluoride, onto an alumina carrier modified with alkali or rare earth-alkali metal ions. The noble metal was preferably deposited in an eggshell concentration profile. An earlier patent assigned to Texaco (215) describes the use of chlorinated alumina in the isobutane alkylation with higher alkenes, especially hexenes. TMPs were supposed to form via self-alkylation. Fluorinated alumina and silica samples were also tested in isobutane alkylation,... 

Gasless Mixture 668/Mn Mn 10, Cu 30, Si 30 Pb02 30%. Pressure on heating of this mixture was developed by sublimation of metals Ref W.A. Show, Development of an Incendiary Pellet , Tech Command Army Chem Center, Md Kept TCR-59 (May 1950)... 

We have proposed the method of synthesis of carbon nanostructures and composites on their base by arc discharge in the liquid phase. In this connection the work on production of ultradispersed metal powders by the electroerosion method [1-4] began in the eighties years and still continues today. Besides carbon nanostructures produced by evaporation of carbon electrodes in the liquid phase, there appears a possibility of producing metal-carbon composites by sublimation of metal in the carbon-containing liquid. In this case the metal nanoparticles form with carbon nanostructures on their surface. 

Heat of sublimation of metal (kcal per gram-atom) 25.9 19 8... 

Latent heats of evaporation and sublimation of metals have been calculated from the vapour pressures by the Clapeyron-Clausius equation ( 7.VIII L). 

The values for the heats of sublimation of metals given in Table CXXXIX although only approximate, bring out some important relationships. In... 

Table CXXXIX. Heats of Sublimation of Metals (kcals)...

Figure 1.5. Periodic variation of the heals of sublimation of metals of Groups 1 to 14 (see Figure 1.4 for meaning of points).

Sublimation of metallic elements from rock or ore samples requires high temperatures. The equipment used is based upon silica furnace tubes in order to withstand the necessary conditions. The silica tube is heated in a furnace and the sublimate condenses either on a cool part of the tube or on a cooled surface immediately after leaving the tube. 

Heat of Fusion For Elements and Inorganic Compounds Heats of Sublimation of Metals and Their Oxides Key to Tables of Thermodynamic Coefficients Thermodynamic Coefficients for Selected Elements Thermodynamic Coefficients for Oxides Entropy of the Elements... 

To illustrate how the third and fourth ionization energies dominate the energetics of f-element oxidation-reduction processes, three cycles will be considered. Only the first cycle, scheme I, includes f d transitions inherent in the sublimation of metals. Scheme I represents the process of oxidation of the metal to the normal 3 -i- oxidation state. 

An important correlation between trivalent f-block ions and their Trivalent atoms (f" ds ) is the P(M) function proposed by Nugent et al. [29]. This function has been utilized for predicting enthalpies of sublimation of metals and enthalpies of formation of aqueous ions. David et al. [27] used heavy-actinide thermodynamic properties to establish a P(M) function relating all of the actinide metals and their 3 + aquo ions. Morss and Sonnenberger [ 103] used newer data to refine this P(M) and to develop similar P(M) plots relating f-block metals and their sesquioxides and trichlorides (Figs 17.5 and 17.6). 

---