Quartz #4/0

Quartz #4/0 is formed by mechanical crushing of quartzite rock. It is the finest Quartz Sand available from its distributor AGSCO, Inc. It is denoted as #4/0 with the number representing a size order. The material is classified as SP according to ASTM Unified Soil Classifications System (USCS). Particles of Quartz #4/0 are angular as shown in Fig. 4.91. Selected DIA images of Quartz #4/0 are also presented in Fig. 4.92. Once again, the low resolution of DIA images is contributing to the inability of the device to capture edge details precisely.

Grain size distributions of Quartz #4/0 are presented using several size descriptors in Fig. 4.93. Fig. 4.94 also depicts variation between number and volume distribution. The size of number distribution is dominated by the finer particles while volume distribution is dominated by the larger particles. The grain size D50 of Quartz #4/0 is 49 µm. Typical particle size diameters in µm corresponding to several particle size descriptors are presented in Table 4.62. Comparison between EQPC sizes corresponding to various particle size diameters by weight/volume and number distributions are also presented in Table 4.63. A large number of finer particles were generated during the crushing process, which resulted in a difference between number and volume distribution calculation.

The density distribution for several commonly used shape descriptors is presented in Fig. 4.95 and summarized in Table 4.64. The distribution of shape parameters is more jagged than other materials owing to the low resolution of the DIA images, which is a result of the tiny particle sizes of this sand. The distribution is clearly non gaussian and is thus fit with Johnson’s parameters. The fitting parameters are summarized in Table 4.65, and the goodness of fit is depicted in Fig. 4.96.


Fig. 4.91. SEM (scanning electron microscope) image of Quartz #4/0 sand.

Fig. 4.91. SEM (scanning electron microscope) image of Quartz #4/0 sand.


Fig. 4.92. Images of Quartz #4/0 acquired using 2D DIA.

Fig. 4.92. Images of Quartz #4/0 acquired using 2D DIA.


Table 4.62 Typical particle size diameters in µm corresponding to several particle size descriptors (by weight/volume distribution).

Quartz #4/0 D1 D5 D10 D30 D50 D60 D90 D99
Feret-max 9 18 26 47 66 76 131 209
EQPC 7 13 17 34 49 57 98 158
Feret-min 5 11 16 33 47 55 90 144


Table 4.63 Typical EQPC corresponding to various particle size diameters by weight/volume and number distributions.

Quartz #4/0 D1 D5 D10 D30 D50 D60 D90 D99
Volume 7 13 17 34 49 57 98 158
Number 3 3 4 5 6 6 21 49


Table 4.64 Statistics of particle shape descriptors for Quartz #4/0 by number and volume distributions.

Quartz #4/0 AR S Cx Rwadell
Number
Mean 0.69 0.73 0.89 …
Median 0.71 0.74 0.89 …
Standard Deviation 0.13 0.09 0.04 …
Volume
Mean 0.69 0.73 0.89 …
Median 0.70 0.74 0.89 …
Standard Deviation 0.13 0.09 0.04 …


Table 4.65 Johnson fitting parameters for Quartz #4/0.

Quartz #4/0 γ δ ξ λ
AR -0.56 1.15 0.27 0.70
S -0.54 0.79 0.49 0.39
Cx -0.63 0.71 0.79 0.15
Rwadell … … … …

Fig. 4.93. Particle size distributions using various size descriptors.

Fig. 4.93. Particle size distributions using various size descriptors.Fig. 4.94. Particle size volume and number distributions.

Fig. 4.94. Particle size volume and number distributions.Fig. 4.95. Particle shape density distributions (based on volume) for Quartz #4/0.

Fig. 4.95. Particle shape density distributions (based on volume) for Quartz #4/0.

Aspect Ratio - Fig. 4.96.1
Sphericity - Fig. 4.96.2
Convexity - Fig. 4.96.4

Fig. 4.96. Johnson fitting of shape descriptors for Quartz #4/0.