▁the ▁z inc ▁is ▁m ined ▁from ▁sul f id ic ▁ore ▁depos its , ▁in ▁which ▁s phal er ite ▁( Z n S ) ▁is ▁nearly ▁always ▁mixed ▁with ▁the ▁sul f ides ▁of ▁co pper , ▁lead ▁and ▁iron . ▁Z inc ▁metal ▁is ▁produced ▁using ▁extract ive ▁met all ur gy . ▁Ro ast ing ▁converts ▁the ▁z inc ▁sul f ide ▁concent rate ▁produced ▁during ▁processing ▁to ▁z inc ▁ox ide : ▁For ▁further ▁processing ▁two ▁basic ▁methods ▁are ▁used : ▁py rom et all ur gy ▁or ▁elect row in ning . ▁Py rom et all ur gy ▁processing ▁reduces ▁z inc ▁ox ide ▁with ▁carbon ▁or ▁carbon ▁mon ox ide ▁at ▁ ▁into ▁the ▁metal , ▁which ▁is ▁dist illed ▁as ▁z inc ▁v apor . ▁The ▁z inc ▁v apor ▁is ▁collected ▁in ▁a ▁cond enser . ▁Elect row in ning ▁processing ▁le aches ▁z inc ▁from ▁the ▁ore ▁concent rate ▁by ▁sul fur ic ▁acid : ▁After ▁this ▁step ▁electro ly s is ▁is ▁used ▁to ▁produce ▁z inc ▁metal . ▁ ▁Cad m ium ▁is ▁a ▁common ▁imp urity ▁in ▁z inc ▁or es , ▁and ▁it ▁is ▁most ▁isolated ▁during ▁the ▁production ▁of ▁z inc . ▁Some ▁z inc ▁or es ▁concentr ates ▁from ▁sul f id ic ▁z inc ▁or es ▁contain ▁up ▁to ▁ 1 . 4 % ▁of ▁cad m ium . ▁ ▁Cad m ium ▁is ▁isolated ▁from ▁the ▁z inc ▁produced ▁from ▁the ▁fl ue ▁dust ▁by