A number of large mining companies are advancing after aluminum producer Alcoa (AA) last night reported higher than expected first quarter earnings per share. THE CATALYST: Alcoa's earnings per share, excluding a number of one-time special items, came in at 11c, versus analysts' consensus estimate of 8c. The company's revenue was slightly lower than expected, but it added that global end market demand growth was solid. Moreover, Alcoa said it continues to expect global aluminum demand to increase 7% in 2013, and stated that it was "committed" to generating positive cash flow this year. TODAY'S PRICE ACTION: In early trading, Rio Tinto (RIO) climbed 3.4% to $47.50, BHP Billiton (BHP) gained 1.8% to $69.25, Freeport McMoRan (FCX) added 1.7% to $33, and Cliffs Natural Resources (CLF) surged 4.2% to $19.60.