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F. Durao etat. / The European Journal of Minerał Processing and Environmental Protection Vol.4, No.3, 1303-0868, 2004, pp. 272-281

Non floated product

FeA Grade (%)

Figurę 7. Washability and grade- recovery curves - flotation of V type clay

In what concerns Z type clay, the results obtained (Table 7) showed that it is jx>ssible to reduce significantly the iron grade by using froth flotation.

Table 7

Best results of bench tests - Z type clay

	Wt (%)			Assays (%)						Distribution (%)
		SiO,	Al,0,	K,0	Na,0	Fe;0,	Ti02	SiO,	Al,0,	K,0	Na>0	Fe,0,	TiO,
Feed	100.0	65.45	18.63	1.26	0.17	5.31	1.35	100.0	100.0	100.0	100.0	100.0	100.0
OFh'	62.3	54.85	26.24	1.66	0.23	5.22	1.37	52.20	87.73	81.77	82.77	61.20	63.09
UFh^1	37.7	82.98	6.06	0.61	0.08	5.47	1.32	47.80	12.27	18.23	17.23	38.80	36.91
OFh'	53.1	51.70	28.44	1.74	0.24	5.25	1.34	41.94	81.06	73.1 1	75.18	52.50	52.67
UF„^2	9.2	73.00	13.51	1.19	0.14	5.02	1.53	10.26	6.67	8.66	7.60	8.70	10.42
OF,^1	3.9	69.50	7.77	0.53	0.18	10.82	5.99	4.14	1.63	1.64	4.14	7.95	17.29
OF,'	2.8	73.30	7.47	0.48	0.10	1 1.06	3.26	3.14	1.12	1.06	1.65	5.83	6.76
OF,^1	2.6	78.50	6.60	0.45	0.09	9.05	1.77	3.12	0.92	0.93	1.38	4.43	3.41
UF, Processed	28.4	86.20	5.64	0.65	0.06	3.85	0.45	37.40	8.60	14.61	10.05	20.59	9.46
Clay (OFh'+ UF,)	81.5	63.72	20.49	1.36	0.18	4.76	1.03	79.34	89.66	87.71	85.23	73.09	62.13

As it can be seen in Fig. 8, the iron and titanium minerals have much faster responses to flotation than V tyf>e clay. It was possible to recover by flotation almost 30% of the clay with an FezOs grade around 3.85% (Fig. 9).

Time (min)

Figurę 8. Kinetic curve - Z type clay

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