Spherical agglomeration pelletization process

A final technique presented for the continuous production of solid dosage forms is extrusion/ spheronization—a technique producing spherical agglomerates of very uniform size. The process is based on low-pressure extrusion and shaping the moist, plastic extrudate into spheres in a spheronizer. These spheres (pellets) are, in most cases, coated after drying and filled into hard gelatin capsules or compressed into... 

A successful variation of oil agglomeration was used for removal and dewatering of soot from a 1—3% soflds suspension consisting of <5 — fim particles in refinery process waters (Fig. 8). Heavy oil was added to the dilute slurry and intensely agitated in a multistage mixer. The soot agglomerated with the oil to form 3—5 mm pellets that were easily screened from the water (95). The pellets contained only 5—10% water. The process was modified to recover very fine clean coal, and it produced highly uniform, hard, spherical pellets 1—2 mm in diameter. 

Newitt and Conway-Jones defined (2) pelletization as the process of transforming a wet, solid mass of finely divided particles into dry, spherical bodies by a continuous rolling or tumbling motion. In a broader sense, pelletization is an agglomeration event used in many powder processes, either for ease of handling or to add value to the product. It spans a range of industries that process solid particles into some suitable form, such as metallurgical, chemical, plastics, fertilizer, rubber, food, and pharmaceuticals (3-6). Since spheres have the lowest surface to volume ratio and exhibit... 

Catalyst-supporting materials are used to immobilize catalysts and to eliminate separation processes. The reasons to use a catalyst support include (1) to increase the surface area of the catalyst so the reactant can contact the active species easily due to a higher per unit mass of active ingredients (2) to stabilize the catalyst against agglomeration and coalescence (fuse or unite), usually referred to as a thermal stabilization (3) to decrease the density of the catalyst and (4) to eliminate the separation of catalysts from products. Catalyst-supporting materials are frequently porous, which means that most of the active catalysts are located inside the physical boundary of the catalyst particles. These materials include granular, powder, colloidal, coprecipitated, extruded, pelleted, and spherical materials. Three solids widely used as catalyst supports are activated carbon, silica gel, and alumina ... 

The shape of the droplets depends in part on the distance the droplets travel before contacting the liquid nitrogen. The distance has to allow sufficient time for the formulation of spherical droplets as they contact the liquid nitrogen. When all processing parameters are carefully characterized and optimized, smooth, spherical pellets can be routinely manufactured. In cases, in which the desired pellet diameter is less than 2 mm, the liquid nitrogen is stirred to prevent agglomeration. 

Overall, the characterization of the melt agglomeration end point using the biexponential mathematical model is simple and without the need to consider the physicochemical properties of the processing materials used. As the process of agglomeration is aimed at making highly spherical pellets, predictive methods based on sphericity will help to capture the ideal end point together with predictive methods based on size. 

After filtration, carbon black aggregates are first packed into agglomerates then into pellets (of millimeter dimensions) in order to produce roughly spherical grains that are easy to handle. The process has several advantages first it is a totally sealed, so that full respect of environment is obtained second a precise control of elementary particle size (from 10 to 100 run) and of aggregate structures is achievable. ... 

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