AccretionAccretion formationFormation within the electrostatic precipitatorElectrostatic precipitator (ESP) of the Copper ConcentrateCopper concentrate RoastingRoasting Plant at CODELCO’s Ministro Hales MineMine is studied, focusing on the accumulation of arsenicArsenic (As2O3) and antimonyAntimony (Sb2O3) oxides. The accretionsAccretion, found on electrodes, collectorCollector plates and walls, reduce ESP efficiencyEfficiency and cause mechanical failures; resistivityResistivity measurements showed that high-resistivityResistivity accretionsAccretion can hinder ESP performancePerformance by causing charge retention, back corona, and component insulation. Mineralogical and chemical analysesAnalysis revealed concentrations of copperCopper, ironIron, sulfates, and arsenicArsenicantimonyAntimony oxides in both fine entrained calcine and accretionsAccretion. While Sb2O3 condenses at operating temperatures, As2O3 unexpectedly forms accretionsAccretion despite its high vapor pressure under these conditions, driven by interactions with sulfates and oxides. The study identified Sb2O3 as a nucleation site for As2O3, facilitating the formationFormation of crystalline oxide networks. Sulfation reactions involving copperCopper and ironIron were also found to contribute to the bonding of particles in accretionsAccretion. These results suggest that increasing the operating temperature of the ESP could mitigate accretionAccretion formationFormation. Further studies are recommended to explore the gas–solid equilibrium of As2O3/Sb2O3 and its implications for improving ESP operationOperation.