Table 3. Minimum Gas Velocity in Gas-Vibro Fluidized Bed.

	dense medium				gas
type	material	ρs (kg/m3)	dp (μm)	voidage	ρf (kg/m3)	viscosity (kg/(m s))	f (Hz)	Umfp (cm/s)	k(f)
monodispersed dense medium	magnetite powder	4600	232	0.45	1.205	17.9 × 10–6	0	12.3	182.78
		4600	232	0.45	1.205	17.9 × 10–6	0.87	11.2	200.72
		4600	232	0.45	1.205	17.9 × 10–6	1.75	10.8	208.16
		4600	232	0.45	1.205	17.9 × 10–6	2.62	10.7	210.10
		4600	232	0.45	1.205	17.9 × 10–6	3.49	10.3	218.27
		4600	232	0.45	1.205	17.9 × 10–6	4.36	10.1	222.59
		4600	232	0.45	1.205	17.9 × 10–6	5.24	10.2	220.41
		4600	232	0.45	1.205	17.9 × 10–6	6.11	10.5	214.11
	magnetite powder	4590	110	0.48	1.205	17.9 × 10–6	0	3.5	184.96
		4590	110	0.48	1.205	17.9 × 10–6	0.85	3.3	196.16
		4590	110	0.48	1.205	17.9 × 10–6	1.70	3.1	208.82
binary mixture dense medium	magnetite powder + quart sand (40%)	3514	158	0.47	1.205	17.9 × 10–6	0	5.5	171.24
		3514	158	0.47	1.205	17.9 × 10–6	0.85	5.2	181.12
		3514	158	0.47	1.205	17.9 × 10–6	1.70	4.9	192.21
		3514	158	0.47	1.205	17.9 × 10–6	2.55	4.4	200.39
		3514	158	0.47	1.205	17.9 × 10–6	3.40	4.2	209.29
		3514	158	0.47	1.205	17.9 × 10–6	4.25	4.1	214.05
	magnetite powder + fine coal powder (10%)	3738	136	0.46	1.205	17.9 × 10–6	0	4	170.75
		3738	136	0.46	1.205	17.9 × 10–6	0.85	3.8	179.74
		3738	136	0.46	1.205	17.9 × 10–6	1.70	3.6	189.73
		3738	136	0.46	1.205	17.9 × 10–6	2.55	3.3	206.98
		3738	136	0.46	1.205	17.9 × 10–6	3.40	3.2	213.45
		3738	136	0.46	1.205	17.9 × 10–6	4.25	3	227.68