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34 AUGUST 2017 MATERIALS PERFORMANCE NACE INTERNATIONAL: VOL. 56, NO. 8 CATHODIC PROTECTION N In this work, linear sweep voltammetry and zero resistance ammeter meth- ods using rotating disk electrodes were utilized to determine and char- acterize the galvanic interaction be- tween mineral particles and AISI 1020 carbon steel immersed in seawater for a combination of exposed areas and electrode rotating rates. Galvanic cur- rent and potential values obtained from both methods were compatible. The experimental galvanic corrosion density values, which are much larger than those of non-galvanic corrosion, reveal a serious threat to pipelines and infrastructure that handle concen- trate suspensions during mineral pro- cessing operations. North ern Chile is an extrem ely arid region containing large deposits of copper and other minerals. Under these condi- tions, recent industrial expansion has been made possible by using seawater in mineral processing. This subjects mining equip- ment and piping to var ying degrees of corrosion depending upon the nature of the materials and operational conditions. In this work, electrochemical methods based on linear sweep voltammetry (LSV ) and zero resistance ammeter (ZRA) techniques employing rotating disk electrodes (RDE) were used to measure and characterize carbon steel (CS) corrosion produced from galvanic C S-min eral c oupl e s w ith th e Galvanic Interaction Between Carbon Steel and Copper Concentrate Genny Leinenweber and Luis Cá C eres V, Universidad de Antofagasta, Antofagasta, Chile mineral in the form of copper concentrate from flotation cells. Experimental Procedures Materials and Reagents Mineral A copper concentrate mineral sample from a local mining company was washed with distilled water and acetone to remove f lotation additives added during the min- eral processing. This sample, with a parti- cle size distribution value of D50 in the range of 2 to 35 μm, was characterized by x-ray diffraction (Table 1). Metal Specimen The working electrode, AISI 1020 CS RDE (SRDE), was comprised of a 4.2-mm diameter rod inserted into a Teflon † cylin- der attached to a rotating shaft (BASi † model RDE-2 rotator system). Wax-Graphite Electrodes Electrochemical tests with copper con- centrate mineral particles were made using a wax-graphite RDE (WRDE). 1-2 Seawater Two seawater samples were taken from a coastal site in Antofagasta, Chile, and then filtered through a membrane filter, with a 0.2- μ m pore size, to remove sus- pended particles. † Trade name.