Note 11. Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2012

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

June 30, 2012	Metric tonnes under contract				Average price per pound
	Zinc		Lead		Zinc		Lead
Contracts on provisional sales
2012 settlements		9,000		2,300	$	0.86	$	0.84
Contracts on forecasted sales
2012 settlements		5,925		2,500	$	1.11	$	1.12
2013 settlements		10,375		13,850	$	1.10	$	1.14

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