Flocculation and dispersion studies of iron ore using laser scattering particle size analysis

Toner is a main component of electrophotographic printing and copying processes. One of the most important ingredients of toner is magnetite (Fe3O4) which provides the tribocharging property for toner particles. In this study, nano- and microparticles of Fe3O4were synthesized using the coprecipitation method and different amounts of lauric acid as a surfactant. The synthesized nano and micro Fe3O4was then used as the charge control agent to produce toner by emulsion aggregation. The Fe3O4and toner were characterized by X-ray powder diffraction (XRD), atomic gradient force magnetometry (AGFM), dynamic laser scattering (DLS), particle size analysis, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The results show that the optimum amount of surfactant not only reduced particle size but also reduced the magnetite properties of Fe3O4. It was found that the magnetite behavior of the toner is not similar to the Fe3O4used to produce it. Although small-sized Fe3O4created toner with a smaller size, toners made with micro Fe3O4showed better magnetite properties than toner made with nano Fe3O4.

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Particle Size Distribution Analysis of an Alumina Powder: Influence of Some Dispersants, pH and Supersonic Vibration

Materials Science Forum ◽

10.4028/www.scientific.net/msf.498-499.73 ◽

2005 ◽

Vol 498-499 ◽

pp. 73-78 ◽

Cited By ~ 3

Author(s):

C.J. Papini ◽

Walter Kenji Yoshito ◽

Douglas Gouvêa ◽

Ricardo Mendes Leal Neto

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Electrostatic Force ◽

Particle Size Analysis ◽

Size Analysis ◽

Alumina Powder ◽

Distribution Analysis ◽

Laser Scattering ◽

Dispersion Condition

It is well known that colloidal powder particles (between 1 mm and 0.001 mm) tend to agglomerate due to electrostatic forces. Then assuring an optimal dispersion condition is essential for good particle-size analysis results, since aggregates or weak agglomerates can be measured as single particles. In this paper the particle size distribution of an alumina powder A1000SG (ALCOA) was measured using distinct dispersion procedures. Distilled water was used as dispersant liquid in the pure state and with additives (citric acid and Duramax D-3005). Dispersion by supersonic vibration was also investigated, but only the application time was varied. Particle size analysis was accomplished by laser scattering technique and the dispersion condition was evaluated through zeta potential. The results showed that the Duramax’s electrosteric impediment is more efficient than citric acid’s electrostatic force, thereby providing better dispersion. Although useful, the supersonic vibration was not good enough to assure an optimal dispersion, at least for the material tested here.

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Roll Pressed LZSA Glass-Ceramics

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.442 ◽

2006 ◽

Vol 45 ◽

pp. 442-446 ◽

Cited By ~ 9

Author(s):

G.M. Reitz ◽

Oscar R.K. Montedo ◽

Orestes Estevam Alarcon ◽

Dachamir Hotza ◽

A. P. Novaes de Oliveira

Keyword(s):

Particle Size ◽

Glass Ceramic ◽

Glass Ceramics ◽

Ceramic Materials ◽

Particle Size Analysis ◽

Modulus Of Rupture ◽

Size Analysis ◽

Potential Candidate ◽

Laser Scattering ◽

Glass Powders

This work reports some experimental results regarding to a Li2O-ZrO2-SiO2-Al2O3 (LZSA) sintered glass-ceramic material obtained by roll pressing of glass powders (mean particle size ≈ 5 μm) with an added (7 wt.%) inorganic material (bentonite) as binder. The composition was characterized using chemical analysis, laser-scattering particle size analysis, DTA, XRD, thermal expansion, modulus of rupture (MOR) and deep abrasion (DA) measurements as well as density measurements and SEM observations. From the results it was verified that the glass-ceramic materials obtained by sintering and controlled crystallization, in the 850-1030°C temperature range, of glass powders, have properties and characteristics decisively better than those of other traditionally used materials. It is concluded that roll pressing technology is a potential candidate to produce sintered glassceramics for many applications, such as, for example, large sheets panels for electrical and thermal insulation.

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