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DERIVATIVE INSTRUMENTS: (Tables)
3 Months Ended
Mar. 31, 2012
DERIVATIVE INSTRUMENTS:  
Copper derivative activity related to copper sales transactions

 

 

 

 

2012

 

2011

 

Zero cost collar contracts:

 

 

 

 

 

Pounds (in millions)

 

46.3

 

105.8

 

Average LME cap price

 

$

5.18

 

$

4.84

 

Average LME floor price

 

$

3.50

 

$

3.02

 

 

 

 

 

 

 

Swap contracts:

 

 

 

 

 

Pounds (in millions)

 

 

119.6

 

Weighted average COMEX price

 

 

$

4.08

 

 

 

 

 

 

 

Realized loss on copper derivatives (in millions)

 

 

$

(35.8

)