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Abstract

Existing literature has failed to provide a substantive explanation for the variability in mineral electrochemistry or methods for its mitigation. The majority of research data has limited use beyond the mineral sampled for experimentation. Even if it did, the conclusions may not translate to different methods or mineral origins. The data itself is not to blame for this challenge, but rather the reporting on how this data was collected. The experimental methods and descriptions of materials are not consistently or appropriately reported. This work sought to understand how different mineral electrodes can affect electrochemical results. Three distinct chalcopyrite origins were used in open circuit potential (OCP), galvanostatic, and potentiostatic experiments. I observed the effects of crevice corrosion, mineral origin and composition, sample preparation, solution stirring, and experimental method. Masking the interface between the resin and mineral surface of the electrodes resulted in upwards of 100 mV potential difference under galvanostatic conditions. As expected, the origin and composition of a mineral affect observed data. Different mineral origins can result in upwards of 242 mV potential difference under 1 μA galvanostatic conditions in stagnant 2 g/L H₂SO₄ at 21°C. Additionally, variation within the same origin can result in approximately 247 mV difference. The effects of electrolyte solution stirring were considerable as well. For example, OCP and galvanostatic potentials can change on the order of 45 mV when stirring and/or nitrogen bubbling. The enclosed data led to the proposal of methods for reducing variability in mineral electrochemistry and structuring reporting guidelines. Mineral electrochemists need to agree on a standard for experimental preparation and reporting to ensure future research can make use of historical data and build upon it.