HOFFMAN ESTATES , Ill . , April 24 , 2009 / PRNewswire-FirstCall / -- AMCOL International Corporation ( NYSE : ACO ) today reported 2009 first quarter net income attributable to AMCOL shareholders of $ 4.2 million , or $ 0.14 per diluted share , compared with $ 8.6 million , or $ 0.28 per diluted share , in the prior-year period .