min     0.03x1 + 0.08x2 + 0.17x3 + 0.12x4 + 0.15x5 + 0.21x6 + 0.38x7
st
LIGA)   x1+x2+x3+x4+x5+x6+x7 = 2000
Fe)	0.15x1+	0.04x2+	0.02x3+	0.04x4+	0.02x5+	0.01x6+	0.03x7 	<= 60	
Cu)	0.03x1+	0.05x2+	0.08x3+	0.02x4+	0.06x5+	0.01x6		<=100	
MN)	0.02x1+	0.04x2+	0.01x3+	0.02x4+	0.02x5                 	<= 40
Mg)	0.02x1+	0.03x2+			0.01x5			<= 30	
Al)	0.70x1+	0.75x2+	0.80x3+	0.75x4+	0.80x5+	0.97x6		>=1500	
SiMin)	0.02x1+	0.06x2+	0.08x3+	0.12x4+	0.02x5+	0.01x6+	0.97x7	>= 250	
SiMax)	0.02x1+	0.06x2+	0.08x3+	0.12x4+	0.02x5+	0.01x6+	0.97x7	<= 300
D1)	x1 <= 200
D2) 	x2 <= 650
D3Min)  x3 >= 400
D3Max)	x3 <= 800
D4Min)  x3 >= 100
D4Max)	x3 <= 700
D5)	x5 <= 1500
