Investigation of the crystallization of zeolite A from hydrogels aged under high pressure

In this study, nanoparticles La1-xSrxFe0.5Mn0.25Ti0.25O3particles were prepared by two successive methods: the mechanical alloying (MA) with the successive sintering and the deagglomeration of MA powders in the demineralized water containing surfactant under ultrasonic irradiation. It is shown that MA powders have coarser particle size of a slightly less than 6 micron in average. Additionally, the particle size distribution was relatively broadening which indicates a large size variation in particle sizes. As MA powders were dispersed in the demineralized water and irradiated by a 40 KHz ultrasonic wave for 5 hours the particle size distribution was improve significantly, it has a narrow particle size distribution with a mean particle size almost 180 nm. The particle has crystallite with mean size 20-26 nm subject to XRD line broadening analysis. Thus, the particles can be called nanoparticles clusters. The study also indicated the breakup of nanoparticle cluster was no longer effective in a prolonged ultra sonication time and yet reagglomeration was obvious. However, the latter was not occurred in a disperse media containing surfactants. In this study, four types of surfactant were used and their influences to the particle sizes were evaluated. According to this study, the four types of surfactants could reduce further the particle size but in different pathways. Sodium Dodecyl Sulphate (SDS) as anionic surfactant reduced the sizes of nanoparticle clusters to almost 180 nm by one step ultra sonication. While cationic, non-ionic and amphoteric surfactants promoted the gel formation in the first place, the nanoparticle clusters were then obtained after an additional heating to breaking the gel form to dry powders. The present of gel was due to stabilization process of the particle to avoid any re-agglomeration between each fine particle. In this paper, we discussed a systematic material preparation towards nanoparticles clusters and the mechanism as well as influence of surfactants in particle size reduction for LSMFTO powders.

Download Full-text

Particle Size Effects on Selectivity in Confined Bed Comminution

Minerals ◽

10.3390/min11040342 ◽

2021 ◽

Vol 11 (4) ◽

pp. 342

Author(s):

Holger Lieberwirth ◽

Lisa Kühnel

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Size Distribution ◽

Size Effects ◽

Experimental Investigations ◽

Ore Processing ◽

Tumbling Mills ◽

Particle Bed ◽

Vertical Roller

Confined bed comminution in high-pressure grinding rollers (HPGRs) and vertical roller mills (VRMs) was previously used preferably for grinding comparably homogeneous materials such as coal or clinker. Meanwhile, it started to complement or even replace tumbling mills in ore beneficiation with ore and gangue particles of rather different breakage behaviors. The selectivity in the comminution of a mixture of particles with different strengths but similar particle size distribution (PSD) of the constituents in a particle bed was investigated earlier. The strength of a material is, however, also a function of particle size. Finer particles tend to be more competent than coarser ones of the same material. In industrial ore processing using confined bed comminution, this effect cannot be neglected but even be exploited to increase efficiency. This paper presents research results on this topic based on experimental investigations with model materials and with natural particles, which were stressed in a piston–die press. It appeared that the comminution result substantially depends on the material characteristics, the composition of the mixture and the PSD of the constituents. Conclusions will be drawn for the future applications of selective comminution in mineral processing.

Download Full-text

Green synthesis of submicron copper powder with narrow particle size distribution via a simple methanol thermal reduction

Dalton Transactions ◽

10.1039/d1dt03464b ◽

2021 ◽

Author(s):

Xiaoping Chen ◽

Jiaqi Fu ◽

Jiangang Li ◽

Bohong Chen ◽

Lei Yang ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Green Synthesis ◽

Size Distribution ◽

Copper Powder ◽

Reduction Method ◽

Particle Distribution ◽

Thermal Reduction ◽

Narrow Particle Size Distribution

In this work, submicron copper powder with narrow particle distribution was synthesized via a simple methanol thermal reduction method without using any surfactants. Smaller copper powder with narrower particle size...

Download Full-text

Organosilicon Comb-Shaped Surfactants for the Synthesis of Polymer Suspensions with a Narrow Particle Size Distribution

Polymer Science Series B ◽

10.1134/s1560090421030052 ◽

2021 ◽

Vol 63 (3) ◽

pp. 209-217

Author(s):

A. A. Ezhova ◽

I. A. Gritskova ◽

S. A. Gusev ◽

S. A. Milenin ◽

V. V. Gorodov ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Narrow Particle Size Distribution

Download Full-text

MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w1-85-2017 ◽

2017 ◽

Vol XLII-3/W1 ◽

pp. 85-89

Author(s):

H. Lin ◽

X. Zhang ◽

Y. Yang ◽

X. Wu ◽

D. Guo

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Landing Site ◽

Radiative Transfer Model ◽

Transfer Model ◽

Particle Sizes ◽

The Mean ◽

The Difference ◽

Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~&thinsp;1&thinsp;m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70&thinsp;%, and the abundances of clinopyroxene and olivine are around 10&thinsp;%. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

Download Full-text

Particle size distribution of sawdust and wood shavings mixtures

Research in Agricultural Engineering ◽

10.17221/8/2010-rae ◽

2010 ◽

Vol 56 (No. 4) ◽

pp. 154-158 ◽

Cited By ~ 5

Author(s):

T. Vítěz ◽

P. Trávníček

Keyword(s):

Experimental Data ◽

Particle Size ◽

Distribution Function ◽

Network Analysis ◽

Particle Size Distribution ◽

Size Distribution ◽

Mass Fraction ◽

Particle Sizes ◽

Wood Shavings ◽

Number Of Particles

Particle size distribution of the sample of waste sawdust and wood shavings mixtures were made with two commonly used methods of mathematical models by Rosin-Rammler (RR model) and by Gates-Gaudin-Schuhmann (GGS model).On the basis of network analysis distribution function F (d) (mass fraction) and density function f (d) (number of particles captured between two screens) were obtained. Experimental data were evaluated using the RR model and GGS model, both models were compared. Better results were achieved with GGS model, which leads to a more accurate separation of the different particle sizes in order to obtain a better industrial profit of the material.

Download Full-text

Experimental Evaluation and Control of Interaction of Gas Environment and Rotary Atomized Spray for Production of Narrow Particle Size Distribution

Process-Spray ◽

10.1007/978-3-319-32370-1_22 ◽

2016 ◽

pp. 903-940

Author(s):

P. Walzel ◽

A. Mescher ◽

J. Kamplade

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Experimental Evaluation ◽

Narrow Particle Size Distribution ◽

Gas Environment ◽

And Control

Download Full-text

Encapsulation of Menthol in Beeswax by a Supercritical Fluid Technique

International Journal of Chemical Engineering ◽

10.1155/2010/608680 ◽

2010 ◽

Vol 2010 ◽

pp. 1-7 ◽

Cited By ~ 10

Author(s):

Linjing Zhu ◽

Hongqiao Lan ◽

Bingjing He ◽

Wei Hong ◽

Jun Li

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Flow Rate ◽

Saturated Solution ◽

Narrow Particle Size Distribution ◽

Solution Flow Rate ◽

Process Conditions ◽

Solution Flow ◽

Expansion Temperature

Encapsulation of menthol in beeswax was prepared by a modified particles from gas-saturated solutions (PGSS) process with controlling the gas-saturated solution flow rate. Menthol/beeswax particles with size in the range of 2–50 μm were produced. The effects of the process conditions, namely, the pre-expansion pressure, pre-expansion temperature, gas-saturated solution flow rate, and menthol composition, on the particle size, particle size distribution, and menthol encapsulation rate were investigated. Results indicated that in the range of studied conditions, increase of the pressure, decrease of the gas-saturated solution flow rate, and decrease of the menthol mass fraction can decrease the particle size and narrow particle size distribution of the produced menthol/beeswax microparticles. An N2-blowing method was proposed to measure the menthol release from the menthol/beeswax microparticles. Results showed that the microparticles have obvious protection of menthol from its volatilization loss.

Download Full-text