Study on the Phase Composition and Particle Size of Boron Mud

The phase composition and particle size of the boron mud is investigated by X-ray diffractometry (XRD), scanning electron microscope (SEM) and laser particle size analyzer. The mainly phase composition of the boron mud are magnesite (MgCO3) and forsterite (Mg2SiO4). The mainly phase composition of the calcined boron mud are forsterite (Mg2SiO4) and a small amount magnesia (MgO). the sizes of the boron mud are about 2~6μm and a few of them are bigger and less than 10μm and the particle size of less than 10μm is about 60%.

Study on Preparation of the High-Density Ammonium Polyvanadate

The high-density ammonium polyvanadate was prepared by means of fine-grained ammonium polyvanadate (APV) produced in vanadium plant. The effects of amount of fine particles, temperature and pH of vanadium solution on preparation of high-density ammonium polyvanadate were investigated. The research results showed that the density of APV could be achieved 0.88g/cm3 under the conditions of addition of 13-31% fine particles, temperature range from 70°C to 100°C and the pH of vanadium solution range from 2.5 to 4, but loss rate of vanadium was the lowest. Moreover, the particle size of high-density ammonium polyvanadate mainly distributes in range of 10 ~ 90μm and is significantly larger than that of the fine APV particles, on the basis of results of the laser particle size analyzer.

The Feasibility Study of Laser Particle Size Analyzer for Thick Pastes

The particle size distribution determines the physical and chemical characteristics of the particle swarm, and then affects rheological properties and transportation resistance characteristics of the thick pastes . Therefore we should find a method to appropriately describe the particle size distribution of thick pastes. Take coal slime to represent, we contrast laser particle size analyzer test with traditional sieving test to find whether the laser particle size analyzer applies to thick pastes or not. The test shows that the laser particle size analyzer which is suitable for the thick pastes to measure their particle sizes. Although its results cant match with the traditional method perfectly, the upper limit particle size can be used as comparison parameter of both methods. In future, the particle size distribution can be directly used, and there is no need to translate it into the sieving particle size distribution.

Comparative Study on Preparation of Al2O3-ZrO2 Composite Powders by the Complexing Precipitate and Carbonblack Coating Methods

Al2O3-ZrO2 composite powders were prepared by the Complexing precipitate method and Carbonblack coating method, and then the powders were characterized by laser particle size analyzer, XRD, and TEM. The results show that: the two methods are both can be used to prepare Al2O3-ZrO2 composite powders. The particle size of the composite powders prepared by Carbonblack coating method is larger than that prepared by Complexing precipitate method. From TEM, it can be seen that the distributions of Al2O3 and ZrO2 in the composite powders prepared by Complexing precipitate method are more uniform. ZrO2 was coated by Al2O3 particles mostly, however, in the composite powders prepared by Carbonblack coating method, part of the particles agglomerated seriously.

Measurement and Characterization of the Particle Size of Refractory Corundum

With introducing briefly the refractory powder materials, the article analyzed the morphology and particle size distribution of commercial different size fraction corundum powder by scanning electron microscopy and laser particle size analyzer. The results showed that most of corundum powder particles were angular spherical, Their particle volume average diameters D(4,3) are greater than median grain sizes D50, and with the difference increasing the distribution curve symmetry becomes worse. Moreover, size frequency distribution curve presents slanting unimodal or bimodal pattern, not completely normal distribution. Besides those, particle size ranges are very wide, e.g. the D90 of 15 μ m is 30 times larger than D10. Therefore, using only the average particle diameter indicates the powder is not comprehensive. The parameters and the size distribution cure measured by laser particle size analyzer can be detailed and accurate to reflect actual powder particle size and distribution, so using them as the commercial corundum powder specification values will be important to enhance the effective utilization of the powder.

Testing and Evaluation on Fractal Characteristic of Cementing Materials Powder

The cement powder materials are evaluated by fractal theory. Fractal characteristic parameters are analysed and evaluated by the method of laser particle size analyzer, microscope, transmission electron microscope. In this paper, cement powder materials has good self-similarity. Fractal dimension of grading is tested and evaluated by laser particle size analyzer, fractal dimension of cluster is tested by microscope, fractal characteristic of particle distribution is tested by transmission electron microscope. Compared with traditional weight of screen residue and specific surface area, those methods are more careful. Fineness fractal parameters and activity of ultra fine fly ash and pulverized slag have good linear dependence relation that is evaluated by fractal dimensions. Fractal characteristics provide an important basis to further explore the inherent relation of cement powder materials and concrete material density effect.

Study on the Preparation of Cu/n-SiO2 Composite Particles by Mechanical Milling

Copper coated nano-SiO2 composite particles were prepared by mechanical milling technology. The effects of milling time on morphology, granularity, component and microstructure of the composite particles were characterized by scanning electronic microscope, laser particle size analyzer, energy depressives spectrometer and transmission electron microscope, respectively. Results showed that dendrite composite particles change to the flaky, and then to spherical ones with the milling time increasing. The particle size decreases firstly and then increases with the milling time increasing. The n-SiO2 particles disperse more homogeneously in the composite particles with the milling time increasing.