Wide Particle Size Distribution Research Articles

Influence of the particle size distribution of coarse-grained refractories on the thermal shock performance

This study investigated the influences of the particle size distribution (characterized by the amounts of fines and coarses and by the maximum particle size (1|3 mm)) and the compaction pressure (50|100 MPa) of die-pressed bars on the behavior of the bulk density, cold modulus of rupture (CMOR) and Young’s modulus E during five thermal shocks (TS). Highest densities were obtained for wide particle size distributions with densest packed coarse aggregates, a slight excess of lubricating fines and a high compaction pressure. Highest CMOR and E were obtained for the same parameters with the exception of a maximum particle size of 1 mm inducing lower flaw sizes. Independent on the compaction pressure, lowest CMOR losses during TS were obtained for a wide particle size distribution with a high number of aggregates constituted of medium-sized grains and densest packed coarses. Supposedly, crack deflection and contact shielding toughening occurred. During TS, E behaved differently. Probably, E was low when there were many flaws. During TS, these led to a large process zone and high decrease of E whereas for batches with higher initial E a crack could propagate with less microstructural interactions giving supposedly a smaller process zone and a reduced decrease.

Taste Masking of Granulated Acetaminophen by Water Insoluble Ethylcellulose Coating.

Bitter tasting of drugs leads to non-compliance especially in the case of pediatric patients due to their inability to swal-low medication. In this study, we aimed to mask the bitter taste of acetaminophen (APAP) particles through coating. A pH independent water insoluble ethylcellulose polymer was used to coat the APAP. The coating of water insoluble ethylcellulose on APAP can have a significant impact on the dissolution profile. Various grades of APAP were used for coating; fine grade, Compap L90% having wide particle size distribution (PSD), and a special granular (SG) APAP 1680 having narrow PSD. Coating was performed using top spray (Vector) for Compap L90% and SG APAP 1680 grade of APAP. Bitter taste of SG APAP was masked after spraying dispersion equivalent to a weight gain of 10% compared to 35% used for Compap L90%. Using bottom spray (Wurster coater, GPCP 2.0), coating was performed on SG APAP 1680 grade of APAP by spraying aqueous dispersion of ethylcellulose (Surelease) equivalent to a weight gain of 10%. The scalability of the top spray process was also evaluated in GPCG 30 and bitter taste was masked by using Surelease dispersion equivalent to a weight gain of 6%. Coated APAP was examined for particle size (PS), particle size distribution (PSD), flowability, and drug release profile. Dissolution was performed using USP apparatus 2 and 4 in phosphate buffer and evaluated for mechanism of drug release. Particle size obtained for coated SG APAP 1680 via top and bottom spray process was 404 µm d(90) and 487 µm d(90) respectively. The results of the study demonstrated the potential of Surelease dispersion in taste masking. The use of SG APAP 1680 having narrow PSD allowed taste masking to achieve at low weight gain without greatly affecting the dissolution profile.

Effect of lognormal particle size distributions on particle spreading in additive manufacturing

Additive manufacturing (AM) has attracted much attention worldwide in various applications due to its convenience and flexibility to rapidly fabricate products, which is a key advantage compared to the traditional subtractive manufacturing. This discrete element method (DEM) study focusses on the impact of particle polydispersity during the particle spreading process on parameters that affect the quality of the final product, like packing and bed surface roughness. The particle systems include four lognormal particle size distribution (PSD) widths, which are benchmarked against the monodisperse system with the same mean particle diameter. The results reveal that: (i) the solid volume fraction of the initial packed particle bed in the delivery chamber increases then plateaus as the PSD width increases; (ii) regardless of PSD width, the solid volume fraction of the particle bed increases with spreading layer height before compression, but decreases with layer height after compression; (iii) the bed surface roughness increases with PSD width or layer height both before and after the compression of the spreading layer; (iv) the extent of increase in solid volume fraction during compression is correlated with the extent of decrease in bed surface roughness; and (v) the broader PSDs exhibit larger fluctuations of solid volume fraction of the particle bed and bed surface roughness due to greater variability in the arrangement of particles of different sizes. The results here have important implications on the design and operation of particle-based AM systems.

Distribution characteristics of soil particle size in alpine steppe and alpine meadow in the source region of the Yangtze River, China.

To explore the heterogeneity of spatial distribution and particle size distribution (PSD) in the main underlying surface soil in the source area of the Yangtze River, we used the fractal theory to describe the soil particle size distribution of alpine steppe and alpine meadow, and analyzed the difference of fractal dimension characteristics of soil of two different underlying surface and its relationship with soil particle composition. The results showed that soil particle size in the study area was mainly concentrated in 100-800 μm. The single fractal dimension (DV) of alpine steppe soil was 2.429-2.508, and that of alpine meadow soil was 2.697-2.743. The soil texture of alpine steppe was coarse, while that of alpine meadow soil was fine. Soil texture was the finest in the 20-30 cm depth, and the coarsest in the 0-10 cm layer. The multi-fractal dimension (capacity dimension D0, information entropy dimension D1, correlation dimension D2) of alpine steppe (0.896-0.961, 0.828-0.887, 0.725-0.819) was higher than that of alpine meadow (0.890-0.914, 0.693-0.744, 0.540-0.603). Compared with the alpine meadow, the alpine steppe had wider soil PSD, more complex soil structure, and higher soil heterogeneity. DV was positively correlated to clay and silt contents, and negatively correlated to sand content. D1 and D2 were negatively correlated with clay and silt contents, and positively correlated with sand content. Sand content was the main factor accounting for the non-uniform distribution of PSD and the changes of fractal dimension.

Application of microbially induced carbonate precipitation to form bio-cemented artificial sandstone

It is difficult to collect and characterise well-preserved samples of weakly-cemented granular rocks as conventional sampling techniques often result in destruction of the cementation. An alternative approach is to prepare synthetic geomaterials to match required specifications. This paper introduces microbially induced carbonate precipitation (MICP) as a method to reliably deliver artificially cemented specimens with customised properties, closely resembling those of soft carbonate sandstones. The specimens are generated from materials with two highly different particle size distributions (PSDs) to access a range of achievable combinations of strengths and porosities. The MICP parameters are kept constant across all samples to obtain similar calcium carbonate characteristics (size of individual crystals, type, etc.), while injected volume is varied to achieve different cementation levels. Although uniform cementation of very coarse sands has been considered very difficult to achieve, the results show that both the fine and coarse sand specimens present high degrees of uniformity and a good degree of repeatability. The unconfined compressive strengths (UCSs) (less than 3000 kPa) and porosities (0.25–0.4) of the artificial specimens fall in the same range of values reported for natural rocks. The strength gain was greater in the fine sand than that in the coarse sand, as the void size in the latter was significantly larger compared to the calcium carbonate crystals’ size, resulting in precipitation on less effective locations, away from contacts between particles. The strengths and porosities obtained for the two sands in this work fall within ranges reported in the literature for natural soft rocks, demonstrating the MICP technique is able to achieve realistic properties and may be used to produce a full range of properties by varying the grain sizes, and possibly the width of PSD. • MICP specimens were generated with a good degree of uniformity and repeatability. • The MICP strategy delivered specimens with controlled mechanical properties. • Properties of artificially cemented sands resemble those of natural soft sandstones. • Varying combinations of UCS and porosity are achieved through different grain sizes.

Spray drying of pure kiwiberry pulp in dehumidified air

Food producers are interested in products with “clean” composition and natural origin. Thus, the elimination of the carriers additions perfectly fits this trend. The aim of the work was to spray dry pure kiwiberry pulp at low drying air temperature (100 °C and 120 °C), possible by the application of dehumidified air. An additional goal was to compare the effect of the kiwiberry variety (Weiki, Geneva and Bingo) and temperature on powder recovery and physicochemical properties of powders. The powder recovery was up to 93%. Kiwiberry powders were characterized by low hygroscopicity and water activity and high total polyphenolics content. Based on hierarchical cluster analysis method, it was found that the kiwiberry variety had a greater impact on the properties of powders than drying temperature: Weiki powders were characterized by the lowest polyphenolics content and the lowest antioxidant activity, while Weiki and Bingo powders had the highest content of aromatic compounds. Powders obtained at lower temperature were characterized by higher water content and activity, lower hygroscopicity, higher apparent density, smaller particle size and wider particle size distribution. The results are of high practical potential, because powders did not contain any carrier material and were characterized by low hygroscopicity. The most recommended is to use Bingo variety and drying temperature 120 °C.

Experimental investigation of the particle size distribution and the influence of operating parameters in limestone drilling

The feature of rock drilling particles is closely related to the improvement of drilling efficiency. The characteristics of drilling particle size distribution (PSD) and its relationship between the operating parameters in limestone drilling are experimentally investigated. Experimental results show that drilling particles are mainly distributed in a range of 0.1–1000 μm and show a bimodal distribution. The PSDs are systematically analyzed by characterization parameters. PSD width defines the distribution scope and uniformity, and large width shows at medium rotation rates or high penetration rates. Compactness reflects the particles packing condition in the drill hole, based on the gradation analysis and Fuller theory, which is less influenced by higher rotation rates while tends to decrease at higher penetration rates. The bimodal feature is described by bimodal span and bimodal amplitude ratio, which characterize the fine and coarse fractions and influence the structure of particulate system, and both of them show a concave function of rotation rate. An overall parameter, average particle size, shows a concave curve under increasing rotation rates and different monotonic curves under increasing penetration rates. Moreover, the agglomeration of fine particles appears at higher rotation rates in the grinding and comminution process, which reduces the breakage of coarse particles and causes an increase of average particle size.

Comparative Study on Cold Compaction Behavior of TiH2 Powder and HDH‐Ti Powder

The compaction mechanism of titanium hydride powder is an important issue because it has a direct impact on density and strength of green compacts and ultimately on the physical and mechanical properties of a final sintered products. In this paper, the characteristics and compaction behavior of titanium hydride and hydrogenation‐dehydrogenation titanium powders are comparatively studied and analyzed for better understanding of compaction mechanism of brittle low‐strength titanium hydride. The results indicate that the particles of titanium hydride powder are easily crushed under compaction loading at relatively low pressure well below compression strength of bulk titanium hydride, the degree of particle crushed increases with the increase of pressure. The compaction behavior of titanium hydride powder mainly includes the rearrangement and crushing of particles in the early compaction stage, minor plastic deformation, if any, and further rearrangement of particle fragments with filling the pores in the later stage. Such compaction behavior provides relative density of green hydride compacts higher than that for titanium powder of the same size. The relatively coarse titanium hydride powder with wide particle size distribution is easier to fill the pores providing highest green density.

Impact of polydispersity on the flow dynamics in the riser of a circulating fluidized bed

Circulating fluidized bed (CFB) has been commonly operated with polydisperse particles with a wide particle size distribution (PSD), which significantly affects solid transportation and the resulting thermochemical performance. Dense gas-solid flows in a pilot-scale CFB riser are simulated via the multiphase particle-in-cell (MP-PIC) coupled with a heterogeneous drag model. Gas-solid hydrodynamics together with the particle-scale information with a wide PSD is discussed. The results show that in the riser, the non-uniformly spatial distribution of solid phase appears with the presence of a core-annulus structure and a dilute-upper dense-bottom profile. The wide PSD gives rise to the axial segregation phenomenon with the accumulation of large particles in the bottom region. Enlarging the superficial gas velocity and PSD width respectively decreases and increases the segregation intensity of solid phase. As compared with gas velocity, the PSD width performs limited impacts on solid concentration, particle-scale information along the axial direction, and solid residence time. The horizontal solid dispersion coefficient is at the scale of 10−3 m2/s, while the vertical dispersion is at the scale of 1 m2/s. For a wide PSD, particles with larger sizes have larger slip velocities but smaller dispersion coefficients in the riser.

Corrosion Behavior of Carbon Steel in Soil with Different Particle Size Distribution during Wet-to-Dry Process

Introduction Corrosion of carbon steel in soil is considered to be similar to that in a neutral solution. That is, soil corrosion is considered to be promoted by water and dissolved oxygen in soil water. In the outdoor environment, soil water content changes due to rainfall. Therefore, in order to understand the corrosion mechanism, it is important to evaluate soil corrosion with a system that reproduces the dry and wet cycle. We measured the time course of the corrosion rate in terms of soil corrosiveness in a single wet and dry cycle. So far, we have focused on the soil particle size as the dominant environmental factor, which is considered to affect the diffusion of water and oxygen in the soil, and have clarified the corrosion tendency. In this study, the relationship between the particle size distribution and corrosion behavior was evaluated using the AC impedance method. Experimental The soil was prepared from three levels of blown lowland soil (Soil A, B and C) with different particle size distribution. The particle size distribution was measured by the laser diffraction/scattering method. The soil was placed in a glass container, and the electrodes were buried in the soil. At the beginning of the experiment, enough water was supplied so that the soil was immersed. The soil water content decreased with time after the water supply had been stopped. The impedance measurements were carried out at constant time interval. The temperature in the chamber was held at 25ºC. Results and discussion Figure 1 shows Nyquist plots obtained from the impedance measurement of the carbon steel in soil A at different time. The equivalent circuit is also shown, where R s is the solution resistance, R ct the charge transfer resistance, CPE the constant phase element and Z W the Warburg impedance. Capacitive loops appeared on the Nyquist plots, and the diameter of the loops varied with the measurement time. R ct was calculated from the radius of the capacitive loops. Figure 2 shows the particle size distributions measured at three levels of soil. The maximum frequency appeared around 10 μm in all soils. Soil A contained more particles larger than 100 μm, although the peak at 10 μm was the lowest. On the other hand, Soil C showed the highest peak at 10 μm, but contained few particles larger than 300 μm. Soil B showed properties intermediate between soil A and C. Figure 3 shows the time course of 1/R ct for each soil. Soil A and B showed a 1/R ct maximum around 200 hours, and the maximum of soil A was greater than that of soil B. On the other hand, soil C did not show a clear maximum value of 1/R ct and remained constant. The difference in the corrosion behavior in each soil is considered to be due to the filling rate of the soil particle. It is known that the larger the particle size distribution is, the larger the filling rate of the particles and the smaller the gap diameter between the particles become. In soil with a wide particle size distribution, water is strongly trapped by capillary force in the narrow gaps between particles. Thus, as the soil dried, a thin water film was maintained on the steel surface, and oxygen was efficiently supplied. Therefore, it is considered that the maximum value of 1/R ct was the largest in soil A. Soil C had a high porosity, and the oxygen was efficiently supplied to the steel surface during the drying process, but at the same time, the wetted area decreased. Therefore, 1/R ct did not show a maximum value and remained constant. Conclusion The corrosion rate of steel in soil with different particle size distributions was evaluated by the AC impedance method. It was found that the corrosion behavior differed depending on the particle size distribution. The corrosion behavior is considered to be due to the diffusion of water and oxygen through gaps between particle. Figure 1

How addition of a nickel cyclohexyl-salen complex impacts a one-pot synthesis of nickel/hierarchically porous carbon monolith catalyst

Synthesis of hierarchically porous carbons incorporating metal nanoparticles can be carried out by a “one-pot” process in which the metal precursor is mixed with polymer precursors and structure directing agents, that undergoes a sol-gel self-assembly polymerization and then pyrolyzed under an inert atmosphere. Such syntheses are potentially cheaper and could make carbon catalysts more compatible with organic solvents. Previous work had shown that addition of metal salts interfered with the self-assembly process. To prevent this interference, and increase thermal stability, a nickel cyclohexyl salen complex was used as metal precursor. Dynamic light scattering (DLS) of the precursor solutions shows the presence of micelles in the absence of added complex. Addition of the complex is observed to give large agglomerates and a reduction in micelle concentration. SEM of the carbons formed shows that the nickel particles have a wide distribution of particle sizes and a heterogenous spatial distribution. Gas adsorption showed only modest changes resulting from nickel complex addition. XRD confirms the formation of nickel nanoparticles. The heterogenous distribution of nanoparticles observed in SEM is consistent with the large agglomerates observed in DLS being nickel cyclohexyl-salen complex which is not fully dispersed in the polymer and therefore gives heterogenous dispersion in the resulting carbon. The metal dispersion and stability of the carbon were improved over that observed with other salen complexes. The resulting catalysts were found to be catalytically active for the reduction of p-nitrophenol by sodium borohydride with catalytic activity consistent with the particle size distributions.

Role of Nd3+ concentration on the microstructure and scintillation behaviour of langbeinite sulphate

Langebeinite (K2Ca2(SO4)3) ceramics doped with increasing concentrations of Nd3+ ions (0.01–0.04 mol%) was prepared by wet chemical precipitation and calcination at 800 °C. Thermal studies revealed high temperature stability of the phosphors. UV–VIS-NIR spectroscopic analysis of phosphors reveal strong absorption peaks representing f → f transitions. Direct bandgap derived from Kubelka-Munk plot was found to be ~5.66 eV. FTIR studies reveal tetrahedral symmetry of the SO42− ions. SEM micrographs reveal the formation of phosphors with wide particle size distribution and elemental composition was analysed using EDX studies. Scintillation studies representing a single high intensity peak around 784 nm is ascribed to 4I9/2 → 4F5/2 + 2H9/2 transition. Langbeinite phosphor with 0.02 mol% of Nd3+ exhibited maximum emission intensity indicating optimal concentration for scintillation studies favouring the development of NIR emitting phosphors.

Particle size, powder properties and the breakage behaviour of infant milk formula

Abstract Dairy powder breakage occurs in many processes and causes deterioration in powder properties but there is currently no research presented in the literature on dairy powder breakage behaviour. The breakage behaviour and the effect of powder properties of an infant milk formula and its sieved size fractions were investigated during three processing methods (powder venturi feeder, lab-scale dilute phase pneumatic conveyor, and laboratory high-speed mixer) based on the changes of particle size distributions (PSD) before and after breakage. Particle size influenced other properties and the breakage behaviour of powders. Four breakage mechanisms were found, dispersion, chipping, disintegration, and splitting, corresponding to the increasing degree of breakage. More intense processing conditions were needed to cause the same breakage mechanism for smaller-sized particles because of their higher powder strength. The breakage of samples with wide PSD often displayed a combination of breakage mechanisms due to the influence of particle size on breakage behaviour.

Synthesis of Magnetic Iron Oxide Nanoparticle from Logas Natural Sand and Its Application for the Catalytic Degradation of Methylene Blue

Structural properties, morphology, and the catalytic activity of hematite (α-Fe2O3) nanoparticles for degradation of methylene blue have been studied. For this purpose, the hematite particles were synthesised from Logas natural sand by 2 steps ball milling method. X-ray diffraction (XRD) confirmed the presence of a hematite (α-Fe2O3) phase. However, other phases such as SiO2 and FeTiO3 are also confirmed by XRD. Scanning electron microscopy (SEM) showed a wide distribution of particle sizes. Moreover, the shape of the grains is irregular form. The effect of reaction time and hematite nanoparticles dosage which affect the efficiency of catalytic reaction was investigated. Catalytic activity of hematite nanoparticles in the degradation of methylene blue (MB) was studied through ultraviolet visible spectroscopy (UV-Vis).

Derivation of soil water retention curve incorporating electrochemical effects

Water retention of clayey soils with wide particle size distributions involves a combination of capillary and adsorbed layers effects that result into suction–saturation relations spanning over multiple decades of matric suction values. The present study provides a physics-based analysis to reproduce the water retention curve of such soils based solely on particle size distribution and porosity. The distribution of inter-particle pore sizes is inferred through a probabilistic treatment of the particle size distribution, which is then used, together with an assigned pore entry pressure, to estimate the inter-particle water volume at a given suction. The contribution to water content from adsorbed layers is also taken into account by considering the balance of electrochemical forces between water and clay material. The total water content is therefore found by summing up the contribution of inter-particle water, as well as adsorbed layers that form around clay particles and around the individual clay platelets. Comparisons with experimental results on nine different soil samples verify the capability of the model in accurately predicting the wide water retention curves without any prior calibration. Additional to capturing the essential features of the water retention curve with remarkable detail, the analytical model also provides insights into the relative contributions of capillary and adsorbed waters to the overall saturation at different suction regimes. Being based upon easily accessible information such as particle size distribution and void ratio, the model can therefore be considered as a substitute for costly and lengthy laboratory and in situ measurements of water retention curve.

Impact of ball filling rate and stirrer tip speed on milling iron ore by wet stirred mill: Analysis and prediction of the particle size distribution

The wet grinding of iron ore powder was investigated using a stirred media mill. In this study, the fitting degree of four cumulative undersize distribution functions was compared and the parameters of the four functions were discussed. It was concluded that the particle size distribution (PSD) of grinding products followed well with the Rosin Rammler Benne (RRB) function. In addition, operational parameters such as ball filling rates, stirrer tip speeds and grinding time have been investigated in terms of the width of PSD and specific energy input. The results indicated that slight differences in the width of PSD could be observed at different ball filling rates and stirrer tip speeds. It was also found that increasing the ball filling rate and stirrer tip speed could improve energy efficiency. Furthermore, an equation was established to predict PSD based on the characteristic particle size of the RRB function and size-energy model, which provided a sound fit to the grinding products under various grinding conditions

A new strategy for strengthening additively manufactured cold spray deposits through in-process densification

Abstract In this study, a novel strategy for strengthening additively manufactured cold spray deposits is proposed, based on a rather under-explored niche of the processing parameters space. We have shown that a combination of two factors (a wide particle size distribution of the feedstock powder and low processing parameters) triggered a successful implementation of this strategy. At such conditions, a significant proportion of the particles (particularly those with a large size) fail to deposit and rebound after their impact instead, initiating the in-process densification effect: by accepting a small price increase trade-off (the wide range powders are inexpensive), the rebounds result in a severe accumulative plastic deformation of the deposited particles and further reduction in porosity. These, in turn, lead to mechanical properties comparable to those produced under high processing parameters (i.e., using N2 gas at high temperatures or using expensive and unsustainable He as the propulsive gas). As a welcome benefit, the detrimental thermal effects encountered in cold spraying using high-temperature processing gas (such as oxidation, nitridation and phase changes) can be effectively minimized using the new low parameters strategy. Overall, the aim of this study is to propose a new manufacturing strategy to fabricate high-performance cold sprayed deposits without the use of expensive and unsustainable He gas.

Transport and characterization of microplastics in inland waterways

Microplastic pollution in floodplains and river channels in 14 locations at six sites along three rivers in Virginia was measured to test the hypotheses that microplastics concentrate in floodplains, exist as larger aggregates with other natural and synthetic particles, and may be different than ocean microplastics. The results show that (1) microplastic concentrations were generally just as high or higher in the floodplain than in the stream channel, (2) microplastics aggregated with natural sediment particles into the “heteroaggregates” predicted theoretically, (3) microplastics were larger in the floodplain than in the stream channel with a wider particle size distribution, (4) microplastic particles were 80 % fragments, 15 % spherical particles, and 5% fibers, and (5) chemically identified microplastics were composed of common packaging plastics that were heavily oxidized or hydrolyzed. The shape and chemical compositions of microplastic particles found was very similar to those observed in and around other rivers studied in the literature but different from the ocean environment. The floodplain could be used to capture river microplastics.

Experimental evaluation of re-entrainment from wet scrubber filtered containment venting systems

Wet scrubber-based filtered containment venting systems (FCVSs) are commonly deployed at nuclear power plants, owing to the high degree of aerosol, iodine, and organic iodine retention that is possible through the pool scrubbing action that takes place during their operation. However, after a FCVS has been operating during a severe accident, the pool water will become extremely contaminated with previously-captured radionuclides, and the bubbling action of gases passing through the pool, could result in the re-entrainment of contaminated liquid droplets into the gas stream. This would produce a secondary source term during the late phases of an accident. As such, a set of experiments have been conducted in order to evaluate the aerosol re-entrainment rates and size distribution from a system prototypical of a pool-type FCVS. Entrainment rates were measured by tracking the carry-over of a NaCl tracer into a set of liquid traps, while the size of the re-entrained droplets was measured with a phase Doppler anemometer. The experiment employed a prototypical venturi nozzle and gas injection conditions to examine the influence of gas flow rate, liquid level, and pool water temperature. Entrainment factors between 5×10−5 and 1×10−3 were measured, and the water droplet count median diameters were between 3 and 13 µm, and fairly wide particle size distributions, with mass mean diameters were on the order of 40–140 µm. These experimental results help the assessment of the potential magnitude of the late phase source term hazards posed by the fission products retained in pool-type FCVS (secondary release), and the potential loading on the secondary dry filter stage (metal fiber filters) employed in FCVSs after the primary pool scrubbing stage. The secondary metal fiber filters should have a high efficiency in capturing water droplets produced through this mechanism, given the droplet’s relatively large size.

Influence of particle size distribution width on GFA index of uniaxially compressed granular materials

This study investigates the influence of particle size distribution (PSD) width on the internal friction and internal pressure ratio of granular materials, and the related flowability of such material when uniaxially compressed in a closed volume. For this purpose, an optical granular friction analyzer (O-GFA) was used to evaluate the granular friction analyzer (GFA) index, which may be related to the internal friction and internal pressure ratio. By examining bronze powder samples with 3 different PSD widths it was shown that as PSD width increases, the load independent GFA index increases, internal friction decreases and the internal pressure ratio remains constant. Furthermore, our study confirms that, determining the GFA index using the O-GFA for characterizing the flowability of uniaxially compressed granular material is an alternative to traditional methods, which require the individual properties of granular materials i.e. internal friction and internal pressure ratio to be determined through two separate tests.