▁and ▁c ath ode ▁through ▁an ▁external ▁circuit . ▁At ▁the ▁applied ▁elect rop ot ential , ▁co pper ▁and ▁less ▁noble ▁elements ▁dissol ve ▁in ▁the ▁electro ly te , ▁while ▁elements ▁more ▁noble ▁than ▁co pper , ▁such ▁as ▁gold ▁and ▁silver , ▁do ▁not . ▁Under ▁the ▁influence ▁of ▁the ▁applied ▁elect rical ▁potential , ▁co pper ▁ ions ▁migr ate ▁from ▁the ▁an ode ▁and ▁depos it ▁on ▁the ▁c ath ode , ▁forming ▁c ath ode ▁co pper . ▁ ▁Elect ro ly t ic ▁ref ining ▁of ▁co pper ▁was ▁first ▁pat ented ▁in ▁England ▁by ▁James ▁El k ington ▁in ▁ 1 8 6 5 ▁and ▁the ▁first ▁electro ly t ic ▁co pper ▁ref in ery ▁was ▁built ▁in ▁New ark , ▁New ▁Jersey , ▁in ▁ 1 8 8 3 . ▁ ▁There ▁were ▁te ething ▁problems ▁with ▁the ▁new ▁technology . ▁For ▁example , ▁the ▁early ▁ref iner ies ▁had ▁trouble ▁producing ▁firm ▁depos its ▁on ▁the ▁c ath odes . ▁As ▁a ▁result , ▁there ▁was ▁much ▁secre cy ▁between ▁ref in ery ▁operators ▁as ▁each ▁stro ve ▁to ▁maintain ▁a ▁compet itive ▁edge . ▁ ▁The ▁nature ▁of ▁the ▁c ath ode ▁used ▁to ▁collect ▁the ▁co pper ▁is ▁a ▁critical ▁part ▁of ▁the ▁technology . ▁The ▁properties ▁of ▁co pper ▁are ▁highly ▁sus cept ible ▁to ▁imp ur ities . ▁For ▁example , ▁an ▁ar sen ic ▁content ▁of ▁ 0 . 1 % ▁can ▁reduce ▁the ▁conduct ivity ▁of