Powder pelletization

Sodium Tetrahydroborate, Na[BH ]. This air-stable white powder, commonly referred to as sodium borohydride, is the most widely commercialized boron hydride material. It is used in a variety of industrial processes including bleaching of paper pulp and clays, preparation and purification of organic chemicals and pharmaceuticals, textile dye reduction, recovery of valuable metals, wastewater treatment, and production of dithionite compounds. Sodium borohydride is produced in the United States by Morton International, Inc., the Alfa Division of Johnson Matthey, Inc., and Covan Limited, with Morton International supplying about 75% of market. More than six million pounds of this material suppHed as powder, pellets, and aqueous solution, were produced in 1990. 

Sohds in divided form, such as powders, pellets, and lumps, are heated and/or cooled in chemical processing for a variety of objectives such as solidification or fusing (Sec. 11), drying and water removal (Sec. 20), solvent recoveiy (Secs. 13 and 20), sublimation (Sec. 17), chemical reactions (Sec. 20), and oxidation. For process and mechanical-design considerations, see the referenced sections. 

Nylon powder. Pellets were dissolved in ethylene glycol under reflux. Then ppted as a white powder on addition of EtOH at room temperature. This was washed with EtOH and dried at 100° under vacuum. 

Polyolefins (Polyethylene, Polypropylene) Powder, pellets Tough and chemical resistant. Weak in creep and thermal resistance. Polyethylene maximum use temperature 210 F, polypropylene 260 F. May be injection and extrusion molded, vacuum formed. Low cost. Antistatic sheet and tiles, heat-shrinkable tubing, deicer boots. 

Vinyls Powder, pellets, General-purpose material. Many Cable shielding,... 

Sand samples were dried at 110 °C and treated with lithium meta and tetraborate to make pressed powder pellets. They were analysed using a X-ray fluorescence Siemens SRS3000 equipment for major and trace elements. For major and trace elements precision is valuated in terms of relative standard deviation being < 1% (Sutarno Steger 1985). 

What is the nature of the material to be measured Is it a gas, a liquid, a slurry or a solid If solid, is it a powder, pelletized resin, fiber, film, or web How large is it Is it homogeneous Is it clear, cloudy, or opaque Is it colored Viscous Bubbly Hot Cold Under high pressure Under vacuum Corrosive Highly toxic Is it moving, and if so, how rapidly Does it need to remain sterile ... 

Mix iron and hematite powder, pelletize the mixture and heat to 837 °C in a sealed silica or gold tube for 24 h. After heating, quench in liquid N2 (Battle and Cheetham, 1979). 

Synthetic inorganic ion exchangers Zeolites Synthetic zeolites (Figure 4.7) are available as powder, pellet, or bead. The greatest advantage of synthetic zeolites against natural zeolites is that they can be manufactured with a wide variety of physicochemical properties. The main disadvantages of synthetic zeolites are... 

To evaluate the effect of sample macroporosity, pressed titanium powder pellets of 45-70% relative density were combusted at 1 bar of nitrogen. Once initiated, the combustion wave front proceeded downward from the surface of the sample and converted Ti to TiN. Conversion was maximum at a relative density of about 58% (Figure 11.1) and the maximum... 

The inclusion of the relatively large chlorine into the polymeric chain reduces the tendency to crystallize. Commercially available grades include a homopolymer, which is mainly used for special applications, and copolymers with small amounts (less than 5%) of vinylidene fluoride.84 The products are supplied as powder, pellets, pellets containing 15% glass liber, and dispersions. Low-molecular-weight polymer is available as oil or grease. The oil is used to plasticize PCTFE.85... 

Tablets are broken by chewing before swallowing with water Disintegrate in oral cavity without drinking water to form a suspension for ease of swallowing Two-piece capsule shells filled with granules, powders, pellets, minitablets, sprinkles, semisolids, oils One-piece capsules filled with oily liquid Single-dose unit bag containing granules...

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