Chemical process, scientific

Production of a metal is usually achieved by a sequence of chemical processes represented as a flow sheet. A limited number of unit processes are commonly used in extractive metallurgy. The combination of these steps and the precise conditions of operations vary significantly from metal to metal, and even for the same metal these steps vary with the type of ore or raw material. The technology of extraction processes was developed in an empirical way, and technical innovations often preceded scientific understanding of the processes. 

The scientific basis of extractive metallurgy is inorganic physical chemistry, mainly chemical thermodynamics and kinetics (see Thermodynamic properties). Metallurgical engineering reties on basic chemical engineering science, material and energy balances, and heat and mass transport. Metallurgical systems, however, are often complex. Scale-up from the bench to the commercial plant is more difficult than for other chemical processes. 

Center for Chemical Process Safety. In 1985, the American Institute of Chemical Engineers estabHshed the Center for Chemical Process Safety (CCPS) (New York). The objective of the CCPS was to help prevent catastrophic chemical accidents by compiling information on the latest scientific and engineering practices, safety programs, and adininistrative procedures of the larger members of the chemical industry, so that they can be shared with other (and particularly the smaller) members of the chemical and petrochemical industries. 

Our immediate and instinctive reaction to an impact or explosion leaves a mental image of utter chaos and destruction. There may be a fascination with the power of such events, but our limited time resolution and limited pressure-sensing abilities cannot provide direct information on the underlying orderly mechanical, physical, and chemical processes. As with other phenomena not subject to direct examination by our human senses, the scientific descriptions of shock and explosion phenomena rest upon a collection of images of the processes which are derived from a range of experiences. The three principal sources of these images in shock science—experiment, theory, and numerical simulation—are indicated in the cartoon of Fig. 3.1. 

Figure 9-24A. Packing factors (stacked packing selected grids). Used by permission of Morris and Jackson, Absorption Towers But-terworth Scientific Publications, and imperial Chemical Industries, Ltd., and adapted by U.S. Stoneware Co. (now, Norton Chemical Process Products Corp.).

Keeping in mind the controversial discussion on new physics in micro reactors [198], we certainly have to be at least as careful when introducing or claiming essentially novel chemical processes. A thorough scientific consideration is required for an exact definition and differentiation here that is beyond the scope of this book. So far, no deep-rooted scientific work has been published analyzing the origin of the novelty of chemistry under micro-channel processing conditions. 

Hessel, V., Hardt, S., Lowe, H., Chemical processing with microdevices Device/plant concepts, selected applications and state of scientific/commerdad implementation, Chem. Eng. Comm., Special edition - 6th Italian Conference on Chemical and Process Engineering, ICheaP-6 3 (2003) pp. 479-484. 

Since 1950, significant technological advances have been made in chemical process safety. Today, safety is equal in importance to production and has developed into a scientific discipline that includes many highly technical and complex theories and practices. Examples of the technology of safety include... 

Martin, F. S. and Miles, G. L., Chemical Processing of Nuclear Fuels, Butterworth Scientific Publications, London, 1958, 102. 

---