Solid lied process costs

All ore mineral deposits lie in or on solid rocks of which the Earth s crust is predominantly composed. The geological processes which are responsible for the formation of rocks also form the ore bodies associated with them. For the formation of an ore body, the metal or metals concerned must be enriched to a considerably higher level than their normal crustal abundance. The degree of such enrichment below which the extraction cost makes the processing of the ore uneconomical is termed the concentration factor. Typical values of the concentration factor for some of the common metals are given in Table 1.5. 

This is true. The power of LDV and other velocity measurement methods lies in the interpretation of the results for the improvement of process performance. Velocity field measurements close to the base of vessels can be used to clarify mechanisms of solids suspension which depend on the shape of the bottom. Velocity measurements close to the top of the vessel can be used to probe dead zones and examine the effect of changing geometry on the size of these dead zones. These measurements are very targeted and can provide very powerful information to the user. This must be balanced with consideration of the costs of purchasing and supporting LDV equipment. 

The principal value of polyethylene lies in its desirable balance of physical properties in the solid state and its chemical inertness. These qualities in combination with its low cost and ready processability make it the material of choice for a wide variety of uses. The balance of physical properties can be controlled by judicious selection of the resin and processing parameters, thereby producing items useful in an extremely broad range of applications. In this chapter the macroscopic properties of polyethylene, with particular emphasis on commercially relevant attributes, are discussed with respect to the key molecular and morphological variables that influence them. 

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