Crystallization industrial apphcations

Crystallization may be carried out from a vapor, from a melt, or from a solution. Most of the industrial apphcations of the operation involve crystallization from solutions. Nevertheless, crystal solidification of metals is basically a crystallization process, and much theory has been developed in relation to metal crystallization. This topic is highly specialized, and is outside the scope of this subsection, which is limited to crystallization from solution. 

All grades of industrial diamond have, to first approximation, the same hardness. However, the size, the toughness or friability, the strength and thermal stabihty, the shape, and impurity contents of the crystals vary greatly and are key metrics for predicting performance in various applications. The abihty to control these properties constitutes a principal advantage of synthetic diamond over natural diamond for industrial apphcations. 

The combined pharmaceutical appHcations account for an estimated 25% of DMF consumption. In the pharmaceutical industry, DMF is used in many processes as a reaction and crystallizing solvent because of its remarkable solvent properties. For example, hydrocortisone acetate [50-03-3] dihydrostreptomycin sulfate [5490-27-7] and amphotericin A [1405-32-9] are pharmaceutical products whose crystallization is faciHtated by the use of DMF. Itis also a good solvent for the fungicide griseofulvin/72%(97-< 7 and is used in its production. 

Other Industrial Applications. High pressures are used industrially for many other specialized appHcations. Apart from mechanical uses in which hydrauhc pressure is used to supply power or to generate Hquid jets for mining minerals or cutting metal sheets and fabrics, most of these other operations are batch processes. Eor example, metallurgical appHcations include isostatic compaction, hot isostatic compaction (HIP), and the hydrostatic extmsion of metals. Other appHcations such as the hydrothermal synthesis of quartz (see Silica, synthetic quartz crystals), or the synthesis of industrial diamonds involve changing the phase of a substance under pressure. In the case of the synthesis of diamonds, conditions of 6 GPa (870,000 psi) and 1500°C are used (see Carbon, diamond, synthetic). 

In the confectionery industry, com symps are used extensively in nearly every type of confection, ranging from hard candy to marshmallows. In hard candies, which are essentially soHd solutions of nearly pure carbohydrates, com symp contributes resistance to heat discoloration, prevents sucrose crystallization, and controls hygroscopicity, viscosity, texture, and sweetness. Maltose symps, high conversion symps, and acid-converted symps (36 and 42 DE) are used for this appHcation. 

Report 3 Advanced Composites, D.K. Thomas, RAE, Famborough. Report 4 Liquid Crystal Polymers, M.K. Cox, ICI, Wilton. Report 5 CAD/CAM in the Polymer Industry, N.W. Sandland and M.J. Sebbom, Cambridge Applied Technology. Report 8 Engineering Thermoplastics, I.T. Barrie, Consultant. Report 11 Communications Apphcations of Polymers,... 

---