Laboratory experiments on agglomeration of particles in a granular stream

Progress in Earth and Planetary Science

Table 1 Physical characteristics of particles

Particle type	Density (kg m^− 3)	Surface energy (J m^− 2)	Poisson’s ratio, ν	Young’s modulus, ε (Pa)	Roughness, Ra (μm)	Restitution coefficient
Glass bead 50 μm	2.5 × 10³	0.025^a	0.17^b	7.3 × 10^10b	1.13 ± 0.24	0.957 ± 0.013
Glass bead 100 μm	2.5 × 10³	0.025^a	0.17^b	7.3 × 10^10b	3.82 ± 0.45	0.957 ± 0.013
Silica sand 73 μm	2.645 × 10^3c	0.025^a	0.17^b	7.3 × 10^10b	–	–
Alumina particle 77 μm	4.0 × 10³	0.041^d	0.24^e	3.85 × 10^11e	–	0.975 ± 0.006

^aHeim et al. (1999)
^bSpinner (1962)
^cThe silica sand grains were used in a previous study (Omura et al. 2016), but we updated the density of the grain according to a measurement of true density made using a pycnometer (SEISHIN ENTERPRISE MAT-7000)
^dBurnham et al. (1990)
^eWong and Bollampally (1999)