Media charging

Media charge 50% of vessel volume Material charge 25% of vessel volume Rotational speed 50-85% of critical speed... 

The general objective of this study was to determine the sample size limits of each of the above mills. Factors which affected mill efficiency and grind times were also evaluated. In some cases, the grind times required to reduce the sample particle size to less than three microns were determined as a function of grind media type, grind media charge and sample size. All particle size analyses were carried out on a Coulter Counter (Model TA II). 

A series of runs were made on this unit using 1/8 inch stainless steel grind media in which the sample size, media charge and slurry concentration were varied. Runs were also made using 1 mm glass media. The grind times versus particle size are shown in Tables II and III. 

Media Charge Sample Size Cone. Particle Size (u) vs. Grind Time... 

Figure 6. Milling Time (to 3 urn) vs. Grind Media Charge (Crescent 6000).

The grinding media charge can be expressed as a percentage of the mill volume, that is, a mill half-full of media contains a 50% charge. The void space present between a static ball charge is approximately 41%. The quantity of material in a mill can be expressed as the ratio of mill volume to the volume of the voids in the ball load, otherwise known as the material-to-void ratio (M/Vratio). In practice, the M/Vratio is kept close to 1, while grinding media charging varies from 20 to 50%. 

Charge media Charge (mm) Detonation condition Detonation velocity (m/s)... 

In this chapter, we will briefly present basic mass transfer mechanisms in polymer membranes and the mechanisms dominating in some membrane separations. In the first part of the chapter, we give a brief description of general transport mechanisms of solutes (charged or not) through a porous media (charged or not). In the second part, we discuss in detail some membranes processes and the transfer mechanisms, interesting from the theoretical point of view. 

Pb = average bulk density of grinding media charge [t/m ]. 

The weight of the grinding media charge of the mill, or of a compartment thereof, can now be calculated from... 

The bed of feed material being ground should cover the top layer of grinding media, but not to any appreciable depth. If the bed is too high or too low, it indicates defective composition of the grinding media charge. With too coarse media the bed will be too low, and vice versa. 

The results of photoinduced absorption in polymer solutions and oligothiophene films and solutions (see Sections 3 and 4) show a profound effect of the surrounding medium on the character of the photo-excited species. Based on these results, we inferred that for pristine conjugated polymers embedded in a nonpolar medium, neutral photoexcitations are favored, whereas in polar media, charged and neutral photoexcitations co-exist. In conjugated polymer/C6o mixtures, embedded in a non-polar medium, energy transfer and triplet sensitization are favored, whereas in polar media, photoinduced electron transfer phenomena clearly dominate. 

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