Methanesulfonic Acid (MSA) in Hydrometallurgy

Abstract This paper reviews the properties of methanesulfonic acid (MSA) and its potential for use in hydrometallurgy. Although MSA is much less known than sulfuric, hydrochloric or nitric acid, it has several appealing that makes very attractive development new circular flowsheets Unlike other organic acids such as acetic a strong ( pK = ? 1.9). In addition, stable against chemical oxidation reduction, no tendency to hydrolyze water. terms environmental impact, low toxicity biodegradable. nature, part geochemical sulfur cycle. A useful property high solubility salts water: methanesulfonate have higher water sulfate salts. Additionally, are compatible with electrowinning metals because anode reaction involves formation oxygen gas (unlike chlorine chloride electrolytes) cathodic reduction anion occurs nitrate electrolytes). particularly interesting lead hydrometallurgy, where offers more environment-friendly alternatives HBF 4 H 2 SiF 6 . However, can also be adopted all hydrometallurgical processes require Brønsted acids. It used metallurgy copper, zinc, cobalt, nickel, rare earths, well recycling from end-of-life products. itself non-oxidizing combination hydrogen peroxide yields strongly oxidizing lixiviants leach copper chalcopyrite dissolve metallic silver. The global production expected increase rapidly near future thanks both industrialization sustainable synthesis process many applications (cleaning fluids, electrolytes electroplating, redox-flow batteries, catalysts synthesis, solvent high-molecular-weight polymers). As result, will become widely available lower price make an increasingly option. Graphical