Quartz #3

Quartz #3 is produced by crushing quartzite rock mechanically and is classified as SP according to the ASTM Unified Soil Classifications System. It is denoted as #3 by its distributor AGSCO, Inc based on its size order in the quartz sands offered by AGSCO. The particles of Quartz #3 are angular in shape, as shown in Fig. 4.55, and selected DIA images of Quartz #3 are presented in Fig. 4.56.

The grain size distributions of Quartz #3 are illustrated in Fig. 4.57 using several size descriptors, and Fig. 4.58 depicts the variation between number and volume distribution. The finer particles dominate the number distribution, while the larger particles dominate the volume distribution. The grain size D₅₀ of Quartz #3 is 1138 µm, and Table 4.38 shows the typical particle size diameters in µm corresponding to several particle size descriptors. Table 4.39 compares EQPC sizes corresponding to various particle size diameters by weight/volume and number distributions. A significant number of finer particles are generated during the crushing process, which results in a difference between the number and volume distribution calculations.

The density distribution for a number of commonly used shape descriptors is presented in Fig. 4.59 and summarized in Table 4.40. The distribution is clearly non gaussian and is thus fit with Johnson’s parameters. The fitting parameters are summarized in Table 4.41, and the goodness of fit is depicted in Fig. 4.60.

Fig. 4.55. Photo of Quartz #3 sand with a 19 mm diameter US Penny for scale.

Fig. 4.56. Images of Quartz #3 acquired using 2D DIA.

Table 4.38 Typical particle size diameters in µm corresponding to several particle size descriptors (by weight/volume distribution).

Quartz #3	D1	D5	D10	D30	D50	D60	D90	D99
Feret-max	192	715	996	1304	1524	1632	3325	3950
EQPC	138	492	755	978	1138	1213	1497	1684
Feret-min	115	387	541	784	914	984	1295	1626

Table 4.39 Typical EQPC corresponding to various particle size diameters by weight/volume and number distributions.

Quartz #3	D1	D5	D10	D30	D50	D60	D90	D99
Volume	138	492	755	978	1138	1213	1497	1684
Number	3	3	4	5	6	6	15	59

Table 4.40 Statistics of particle shape descriptors for Quartz #3 by number and volume distributions.

Quartz #3	AR	S	Cx	Rwadell
Number
Mean	0.62	0.72	0.93	0.44
Median	0.63	0.73	0.93	0.44
Standard Deviation	0.15	0.08	0.03	0.09
Volume
Mean	0.63	0.72	0.93	0.42
Median	0.64	0.73	0.94	0.42
Standard Deviation	0.14	0.07	0.02	0.09

Table 4.41 Johnson fitting parameters for Quartz #3.

Quartz #3	γ	δ	ξ	λ
AR	-0.50	1.30	0.13	0.85
S	-2.59	1.99	0.09	0.82
Cx	-3.84	1.64	0.53	0.45
Rwadell	-0.33	2.68	0.39	0.22

Fig. 4.57. Particle size distributions using various size descriptors.

Fig. 4.58. Particle size volume and number distributions.

Fig. 4.59. Particle shape density distributions (based on volume) for Quartz #3.

Fig. 4.60. Johnson fitting of shape descriptors for Quartz #3.