Slurry concentration

The recommended solvents for various stationary phases vary from one manufacturer to the next and will depend upon the stationary phase being packed. However, the concentration of stationary phase in solvent is generally in the region of 1 kg 

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Thick mixtures with viscosities greater than 10 Pa s are not readily mixed in conventional stirred pots with either propeller or turbine agitators. The high viscosity may be due to that of the matrix fluid itself, to a high slurry concentration, or to interactions between components. 

Means should be provided for measuring and varying the slurry concentration in the contacting zone up to 50 % by volume. 

Relate the filter cake deposited per unit volume of clear filtrate collected r to feed slurry concentration, w. 

Figure 17-9. Surfactants in a slurry concentrate sorbitan monooleate, ethoxylated nonylphenol.

H. D. Brannon. Fracturing fluid slurry concentrate and method of use. Patent EP 280341, 1988. 

The need to separate solid and liquid phases is probably the most common phase separation requirement in the process industries, and a variety of techniques is used (Figure 10.9). Separation is effected by either the difference in density between the liquid and solids, using either gravity or centrifugal force, or, for filtration, depends on the particle size and shape. The most suitable technique to use will depend on the solids concentration and feed rate, as well as the size and nature of the solid particles. The range of application of various techniques and equipment, as a function of slurry concentration and particle size, is shown in Figure 10.10. 

The capacity of filtration centrifuges is very dependent on the solids concentration in the feed. For example, at 10 per cent feed slurry concentration 9 kg of liquid will be centrifuged for every 1 kg of solids separated whereas with a 50 per cent solids concentration the quantity will be less than 1 kg. For dilute slurries it is well worth considering using some form of pre-concentration such as gravity sedimentation or a hydrocyclone. 

Table 7.3 Effect of slurry concentration and C02 flow rates, Orifice diameter on conversion and cavitation yield [46]...

It is desired to increase the rate of filtration by raising the speed of rotation of the drum. If the thinnest cake that can be removed from the drum has a thickness of 5 mm, what is the maximum rate of filtration which can be achieved and what speed of rotation of the drum is required The voidage of the cake = 0.4, the specific resistance of cake = 2 x 1012 m-2 the density of solids = 2000 kg/m3, the density of filtrate = 1000 kg/m3, the viscosity of filtrate = 10-3 N s/m2 and the slurry concentration = 20 per cent by mass solids. 

Water jet cutting and burster washout for chemical agent munitions Literature review on energetic slurry concentrations and handling... 

EDE. 2001b. Literature Review on Energetic Slurry Concentrations and Handling, August 21. Salt Lake City, Utah El Dorado Engineering, Inc. 

The tested GCC was ground to a particle size of 90% < 2 microns. The slurry concentration was 74.5%, and dispersant concentration was 0.73% (as polymer solids/dry CaC03). 

The free world market for cerium-oxide based polishing compounds is not large—approximately 4400 metric tons per year—, and we do not see a substantial growth potential despite the 11% annual growth in sales of spectacle lenses. The reason is twofold first, faster more efficient polishing compounds are available which can be used in slurry concentrations one-half that of a few years ago second, fully half the market for ophthalmic glass lenses has been captured by plastic lenses of CR-39 polymer. Cerium oxide is ineffective in polishing this material specially treated alumina or stannic oxide are used. 

A hydrocyclone assembly is required to handle 10,000 gpm of slurries of a solid with specific gravity 2.9 with a cutoff point of dx = 100 fim. The allowable pressure is AP = 5 psi. Several slurry concentrations V will be examined. Substituting into Eq. (12.1), with z the function of V in parentheses,... 

From Figure 12.3(b), with 5 psi a 660 mm unit will handle 1000 gpm and have a cutoff between 50 and 150 um. This corresponds to the calculated data with V about 19 vol %. For a more detailed study of hydrocyclone sizing, the article of Mular and Jull (in Mular and Bhappu, 1980, pp. 376-403) may be consulted. The pressure drop can be adjusted to compensate for changes in slurry concentration. 

At slurry concentrations below 0.01%, both reagents give similar values for surface hydroxyl concentration which are consistent with literature values ( 4.6 hydroxyls/100 A2). 

Figure 9. Apparent surface hydroxyl concentration as a function of slurry concentration O Reaction with Zr(V-allyl)k, X Reaction with CH3MgI...

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