Physical bulk density

Physical Properties. Physical properties of waste as fuels are defined in accordance with the specific materials under consideration. The greatest degree of definition exists for wood and related biofuels. The least degree of definition exists for MSW, related RDF products, and the broad array of ha2ardous wastes. Table 3 compares the physical property data of some representative combustible wastes with the traditional fossil fuel bituminous coal. The soHd organic wastes typically have specific gravities or bulk densities much lower than those associated with coal and lignite. 

There is considerable variance in the porosity of limestones, thus the bulk densities generally are 2000 2800 kg/m (125-175 Ib/ft ). The density of some chalk limestones are even less. Dolomitic stones average 2—3% higher densities than high calcium ones. Depending on the physical size of the quicklime particles and their divergent porosities, bulk densities are 770 1120 kg/m (48-70 Ib/ft ), and densities of their hydrates 400 640 kg/m ... 

The general manufacturing scheme for phosphate salts is shown in Figure 11. Condensed phosphates are prepared from the appropriate orthophosphate or mixture of orthophosphates, so the preparation of orthophosphates must be considered first for the manufacture of any phosphate salt. Phosphoric acid is neutralized to form a solution or slurry with a carefully adjusted acid/base ratio according to the desired orthophosphate product. The orthophosphate may be recovered either by crystallization from solution, or the entire solution or slurry may be evaporated to dryness. The dewatering (qv) method is determined by the solubihty properties of the product and by its desired physical properties such as crystal size and shape, bulk density, and surface area. Acid orthophosphate salts may be converted to condensed phosphates by thermal dehydration (calcination). 

The most important properties of refractory fibers are thermal conductivity, resistance to thermal and physical degradation at high temperatures, tensile strength, and elastic modulus. Thermal conductivity is affected by the material s bulk density, its fiber diameter, the amount of unfiberized material in the product, and the mean temperature of the insulation. Products fabricated from fine fibers with few unfiberized additions have the lowest thermal conductivities at high temperatures. A plot of thermal conductivity versus mean temperature for three oxide fibers having equal bulk densities is shown in Figure 2. 

In the United States, a number of physical tests are performed on siUcon carbide using standard AGA-approved methods, including particle size (sieve) analysis, bulk density, capillarity (wettabiUty), friabiUty, and sedimentation. Specifications for particle size depend on the use for example, coated abrasive requirements (134) are different from the requirements for general industrial abrasives. In Europe and Japan, requirements are again set by ISO and JSA, respectively. Standards for industrial grain are approximately the same as in the United States, but sizing standards are different for both coated abrasives and powders. 

The bulk density of cellulose acetate varies with physical form from 160 kg/m (10 lb /ft ) for soft dakes to 481 kg/m (30 lb /fT) for hammer-milled powder, whereas the specific gravity (1.29—1.30), refractive index (1.48), and dielectric constant of most commercial cellulose acetates are similar. 

The physical properties of spray-dried materials are subject to considerable variation, depending on the direction of flow of the inlet gas and its temperature, the degree and uniformity of atomization, the solids content of the feed, the temperature of the feed, and the degree of aeration of the feed. The properties of the product usually of greatest interest are (1) particle size, (2) bulk density, and (3) dustiness. The particle size is a function of atomizer-operating conditions and also of the solids content, liquid viscosity, liquid density, and feed rate. In general, particle size increases with solids content, viscosity, density, and feed rate. 

Daitomaceous Earth. .. Loss on ignition, 11.50. Diatomaceous Earth -Physical Properties. Bulk Density, 0.26 gm/cc. Temperature Resistance, 1400 DC.. .. http //www.infoindia.com/uff/daito.html... 

FIG. 6 A comparison of the Monte Carlo (points), HHNCl, HNCl, and PYl density profiles. The results are for bulk density 0.403 (lower group of curves) and 0.741 (upper group of curves). The curves at z — 0, are, from the bottom, from HHNCl and HNCl approximations. (Reprinted from A. Trokhymchuk, D. Henderson, S. Sokolowski. Local density of overlapping spheres near a hard wall A density functional approach. Physics Letters A 209, 317-320. 1995, with permission from Elsevier Science.)... 

The tests that reflect physical properties of the catalyst are surface area, average bulk density, pore volume, and particle size distribution. 

Plot the physical properties of the equilibrium catalyst. The plotted properties will include particle size distribution and apparent bulk density. The graph confirms any changes in catalyst properties. 

Soil physical properties most likely to be altered by biomass burning are soil structure, soil wettability, and clay mineralogy (Table HI) (43). The destruction of organic matter results in losses of soil structure, increases in bulk density, diminished aggregate stability and decreases in macropore space (44). 

G.R. Blake and K.H. Hartge, Bulk density, in Methods of Soil Analysis Part 1 Physical and Mineralogical Methods, ed. A. Klute, Second edition, American Society of Agronomy and Soil Science Society of America, Madison, Wl, pp. 363-375 (1986). 

Particle shapes influence properties such as surface area, bulk density, flow, and so on. A number of methods are available for describing shape from simpler qualitative descriptions, through property ratios, to techniques that employ fast Fourier transformations to describe the projected perimeter of the particle. The measurement of the shape and the relevance of the data obtained are generally the two difficulties associated with particle shape. Fortunately, in the processing of materials physically unlike those in chemical processing, shape is perhaps is less significant and is more often than not inherently accounted for in the nominal diameter. 

After determining the relevant physical properties (i.e., particle size, solids particle density and bulk density), the next step is to evaluate some of the existing techniques of powder classification. 

In this chapter the physical properties of resins related to processing will be described. The chapter and Appendix A4 include physical properties for many resins. These properties include bulk density and compaction, lateral stress ratio, stress at a sliding interface, melting flux, heat capacity, thermal conductivity, and melt density. Some of these properties are easy to measure by many laboratories while others such as the melting flux and stress at a sliding interface can be measured in only a few places using highly specialized equipment. 

The powder s flow properties are also important because they control the physical processes that are used to manipulate the material. Carrs s index, which is a measure of powder bulk density and angle of repose, provides information on flow properties, which are important when production utilises high-speed tableting machines. 

The literature contains relatively little data on the physical properties of binder solutions and therefore conclusions must be drawn largely from qualitative observations. For example, Davies and Gloor (1972) have linked the effectiveness of binders with their adhesiveness or tackiness and have found that more viscous binder solutions increase the size of granules and reduce the bulk density. Hydroxypropylcedulose (HPG), with which atomising difficulties were encountered because of its viscosity, was responsible for the largest increase in mean particle... 

Using the catalyst vendor s equilibrium catalyst report, the physical properties of the circulating catalyst may be monitored for any change. Albemarle routinely analyzes a sample of the circulating catalyst inventory among others for physical characteristics, including surface area (SA), metal content, apparent bulk density (ABD), and particle size distribution (PSD). 

The additive mnst have a high degree of physical integrity so that it is able to withstand the severe hydrothermal environment of the FCCU. Factors such as attrition resistance, apparent bulk density, and particle size distribution are critical in retaining the additive in the unit. 

Beyond similarities in bulk density, the physical properties of fly ash and bottom ash are very distinct (Table 3). The diameter of fly ash particles is generally several orders of magnitude smaller than that of bottom ash particles, leading to... 

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