Question

The Bayer process, which is over 120 years old, is the only process used for the commercial production of alumina today and remarkably the main sub-processes that underpin the Bayer process are essentially the same as those used over 120 years ago. The lack of development of a new commercial process for the production of alumina is due to a variety of reasons. In summary however it is essentially due to the fact that no alternative process that has been developed has been more economical then the Bayer process. Discuss an alternative process for producing alumina from bauxite (your alternative process may include a maximum of two of the major sub-processes used in the Bayer process (i.e. digestion in alkali, clarification (settling / filtration), seeded precipitation, calcination)). Include a brief comparison of cost between your alternative process with similar stages used in the Bayer process. Include a discussion of any potential environmental challenges that may be encountered using your alternative process.

NOTE: The chemistry that you propose in your alternative process must be reasonable.

Answer 1

solution - free radical polymerization consists of the elementy reactions of initiation, propagation and and termination. Termination refers to the bimolecular neretion of propagating radicals by combination (ory disproportionation that leads to the deactivation of propagating radical chain ends. combination versus disproportionation: the relative extents of the two different modes of bimolecular termination, disproportionation ana combination, often expressed as the ratio of their respective rate coefficients is difficult to measure as manifested by the spread in book. . Termination occurs mainly by combination for mest vinyl monomers, although disproportionation usually makes a significant contribution when the propagating radical is stericany hindered on possesses. PDI is higher for combination than disproportionation.