Toth process

Both the Toth and Alcoa processes provide aluminum chloride for subsequent reduction to aluminum. Pilot-plant tests of these processes have shown difficulties exist in producing aluminum chloride of the purity needed. In the Toth process for the production of aluminum chloride, kaolin [1332-58-7] clay is used as the source of alumina (5). The clay is mixed with sulfur and carbon, and the mixture is ground together, pelletized, and calcined at 700°C. The calcined mixture is chlorinated at 800°C and gaseous aluminum chloride is evolved. The clay used contains considerable amounts of silica, titania, and iron oxides, which chlorinate and must be separated. Silicon tetrachloride and titanium tetrachloride are separated by distillation. Resublimation of aluminum chloride is requited to reduce contamination from iron chloride. 

A consolidated picture of the different processes for the production of aluminum is shown in Figure 6.25. There are altogether four processes (i) Alcan process (ii) Toth process (iii) Alcoa process and (iv) Bayer process. 

Figure 6.25 Flowsheets for Al extraction stream 1 Bayer process, 2 Alcoa process, 3 Toth process, 4 Alcan process.

A pelletized mixture of clay, lignite and a small amount of NaCl is chlorinated at 900°C, producing gaseous AICI3 (Toth process). Alternatively, alumina is mixed with about 20% by weight carbon and a small amount of sodium... 

More efficient processes are the Alcoa and Toth processes which require much less electric power than the Hall process. Another method, using no electricity, involves heating a mixture of aluminum ores with a coal-derived fuel in a closed furnace. Still another process called calsintering, using fly ash as a source of alumina, has been described (1978). See calsintering. 

See Toth process kaolinite aluminum silicate clay Pharmolin [Engelhard]. 

Use Ferroalloys (steel manufacture), nonferrous alloys (improved corrosion resistance and hardness), high-purity salt for various chemical uses, purifying and scavenging agent in metal production, manufacture of aluminum by Toth process. 

The resting state of the propanoate catalysts may well be an acyl complex [60,61], while the attack of alcohol at the acylpalladium complex is considered to be the rate-determining step. It is probably more precise to say that fast preequilibria exist between the acyl complex and other complexes en route to it and that the highest barrier is formed by the reaction of alcohol and acylpalladium complex. The precise course of the reaction is still not known presumably deprotonation of the coordinating alcohol and the migratory elimination are concerted processes, accelerated by the steric bulk of the bidentate ligand. Toth and Elsevier showed that the reaction of an acetylpalladium complex and sodium methoxide is very fast and occurs already at low temperature to give methyl acetate and a palladium(I) hydride dimer [46]. 

Del-Cul, G.D., Bond, W.D., Toth, L.M. et al. 1994. Citrate based TALSPEAK lanthanide-actinide separation process. ORNL/TM-12785. 

Particle production is an important process of particle technology. The paper of J. Toth et al discusses the results of investigation on salting-out precipitation of glycine and sodium chloride. In another paper, production of micronized cocoa butter particles by supercritical process was reported by J.-J Letourneau et al. 

Varadi M, Toth A, Rezessy J (1992) Application of NIR in a fermentation process. VCH Publishers, New York... 

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