Agglomeration, solids

Figure 12. Comparison of simple macrohomogeneous agglomerate (solid line) and thin-film (dashed line) cathode models to experimental data (diamonds). Data are adapted from ref 34.

The initially liquid reaction product, LiF, becomes an agglomerated solid below about 500 K. 

FIG. 15 Characteristic stress-strain behavior of an elastic compressible agglomerate (solid lines) in common testing configurations uniaxial tension, uniaxial compression, and hydrostatic compression (from Bika et al., 2001). Yield point ay and tensile strength a, are indicated. 

Tab. 8.4 summarizes the most important advantages of agglomerated solid mineral and metallurgical wastes. Bullet points 1 to 3 are self-explanatory since the particle size of most solid wastes is too small for direct processing or is ultrafme after they were removed from gaseous or liquid plant effluents as solid pollutants (Section 8.1). 

So far, the sizing of machines for the agglomeration in stirred suspensions and immiscible liquid agglomeration is totally based on common sense approaches, experience with similar applications and trial and error. Thickeners are primarily designed to handle the amount of contaminated liquid at low flow conditions, which do not disturb the accretion (assisted by flocculation agents [B.48, B.97]) and the settling behavior of the suspended agglomerating solids. 

Unfortunately the use of such a relation other than illustrating first principles is extremely limited in industrial applications because both the specific area of the particles Sq and the porosity 8 are extremely difficult to characterize when dealing with agglomerated solids that are also compressible. A more useful analysis can be made to characterize the filterability of a slurry by the use of the filtration equation as defined by equation (2) below, that shows how the filtration rate is affected by the filter operating parameters (pressure drop AP, filtration area A, filter medium resistance and also slurry related parameters (viscosity p, solids concentration w, specific cake resistance rj ... 

Wet scrubbers are ideally suited for applications where the recovered solid needs to be dissolved or slurried in a liquid for remrn to the process, or where die agglomerated solids are difficult to handle. Outside these limits, other equipment should be carefully considered in lieu of wet scrubbers. 

Two or more agglomerated solid substances, not suited for dry trituration, are roughly mixed before trituration with some molten base. Once more a plastic or stainless steel mortar is used, but with a scraper instead of a plastic pestle. Thereafter the mixture is rubbed, with no more than a half to an equal volume of molten base, in the same mortar, but now again with a plastic pestle. 

Tapas, A.R., Kawtikwar, P.S., Sakarkar, D.M. (2010). Spherically agglomerated solid dispersions of valsartan to improve solubility, dissolution rate and micromeritic properties. International Journal of Drug Delwery, 2,304-313. 

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