Measurement and analysis of the resting angle of titanium dioxide (2)

2 Sabbath Angle Influencer
2.1 Crystal Effect on Rest Angle
Titanium white powder has two important crystal classifications, namely, redstone and sharp titanium, in which a titanium atom is surrounded by six oxygen atoms. The redstone type belongs to the four-way crystal system, six oxygen atoms are at the angle of the positive octagonal body, the lattic is small and tight, the stability is very high. Sharp titanium type belongs to the four-way crystal system, the temperature is higher than 610 degrees C began to convert to the gold-redstone type, the structure is relatively loose than the gold-redstone type, the density is small. Because the surface properties of titanium dioxide after coating are completely changed, there is no comparability of resting angle, so the untreated titanium dioxide rough products are used for the comparison of resting angle. Two types of titanium dioxide rough, according to the above-mentioned simple measuring device for measurement, the results can be seen in Table 1.From Table 1, it can be seen that the coarse resting angle of the gold-redstone titanium white powder is slightly err than that of the sharp titanium type, which may be due to the large density of the pile of the goldstone-type titanium dioxide, the particles are arranged closely between each other, in the same surface properties can achieve high resting angle accumulation.
2.2 Effect of particle size distribution on resting angle
Particle particle size distribution is also a factor affecting resting angle, particles with finer particle size distribution can accumulate more closely, and particles with coarse particle size distribution result in a looser structure.
in order to make the granular distribution more digital, the introduction of D10, D50, D90 three indicators. D50 represents the particle size corresponding to a sample's cumulative particle size distribution ratio of 50%. Its physical significance is that the particle size is greater than its particle size accounted for 50%, less than its particles also accounted for 50%, D50 is also called the median particle size or median particle size, often used to indicate the average particle size of the powder. D10 and D90 represent a similar meaning to D50. Take 5 gold-redstone titanium white powders with similar surface properties, and test the particle size distribution of the above 5 samples, the specific data can be found in Table 2.the distribution of the above five samples were measured at the resting angle, the results of which are shown in Figure 2.figure 2 shows that there is a more direct relationship between the resting angle and the particle size distribution of titanium dioxide, that is, the finer the particle size distribution, the greater the resting angle. The main reason for this phenomenon is that fine particles in the accumulation process can be effectively filled in the gaps in the particles, so that the whole accumulation is more closely, under the action of external forces is not easy to deform and distort. Particles with large particle size distribution slip easily under the effect of gravity and cannot accumulate into cones with large angles..