Note 11. Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2012

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

September 30, 2012	Metric tonnes under contract				Average price per pound
	Zinc		Lead		Zinc		Lead
Contracts on provisional sales
2012 settlements		8,525		3,400	$	0.88	$	0.96
2013 settlements		2,200		—	$	0.97		N/A
Contracts on forecasted sales
2012 settlements		—		600		N/A	$	1.12
2013 settlements		10,250		16,850	$	1.06	$	1.12

December 31, 2011	Metric tonnes under  contract				Average price per pound
	Zinc		Lead		Zinc		Lead
Contracts on provisional sales
2012 settlements		9,600		2,600	$	0.86	$	0.89
Contracts on forecasted sales
2012 settlements		20,500		15,900	$	1.12	$	1.12
2013 settlements		8,275		11,150	$	1.14	$	1.17