▁Bol iden ▁also ▁own s ▁and ▁oper ates ▁the ▁A it ik ▁open ▁pit ▁mine , ▁which ▁is ▁one ▁of ▁Europe ' s ▁biggest ▁co pper ▁mines . ▁Metal ▁gr ades ▁at ▁A it ik ▁are ▁low , ▁but ▁this ▁is ▁compens ated ▁for ▁by ▁high ▁product ivity ▁levels ▁and ▁efficient ▁mill ing ▁processes ▁that ▁also ▁explo it ▁the ▁ore ' s ▁gold ▁and ▁silver ▁content . ▁An ▁expansion ▁project ▁that ▁will ▁double ▁A it ik ' s ▁ore ▁production ▁to ▁ 3 6 ▁million ▁t onnes ▁per ▁an num ▁by ▁ 2 0 1 4 ▁▁ ▁began ▁in ▁ 2 0 0 7 ▁and ▁will ▁be ▁completed ▁in ▁ 2 0 1 0 . ▁ ▁Sm el ters ▁Business ▁Area ▁Sm el ters ▁ref ines ▁both ▁metal ▁concent rate ▁and ▁secondary ▁materials ▁to ▁produce ▁base ▁and ▁pre cious ▁met als ▁at ▁sm el ters ▁in ▁Sweden , ▁Finland ▁and ▁Norway . ▁The ▁main ▁met als ▁are ▁z inc ▁and ▁co pper ▁but ▁the ▁production ▁of ▁lead , ▁gold ▁and ▁silver ▁also ▁makes ▁a ▁substantial ▁contribution ▁to ▁the ▁Business ▁Area ' s ▁reven ues . ▁Other ▁products ▁include ▁sul ph ur ic ▁acid ▁and ▁al umin ium ▁flu or ide . ▁Bol iden ▁own s ▁and ▁oper ates ▁two ▁z inc ▁and ▁two ▁co pper ▁sm el ters ▁and ▁one ▁lead ▁sm elter . ▁The ▁K ok k ola ▁z inc ▁sm elter ▁in ▁Finland ▁is ▁the ▁second ▁largest ▁in ▁Europe ▁and ▁the ▁fifth ▁largest ▁in ▁the ▁world , ▁and ▁mainly ▁produces ▁an