Kinnunen and Puhakka proposed the change amplitude of the leaching temperature would distinctly affect the leaching kinetics in the chloride media solution [161]. He found the production of copper ions was enhanced from 67 °C to 90 °C under the condition of 0.25 g/L of Cl− concentrate but was descended at 50 °C. The leaching rates of chalcopyrite in ferric-chloride media solution found to

be faster than that in media solution of ferric-sulfate. The rational analysis was the exist of the chloride in the leaching solution caused the formation of a crystalline and more porous sulfur layer, not the amorphous or cryptocrystalline film as the second phase under the absence of chloride [140]. The second phases produced

during the leaching process, such as elemental Belnacasan cost sulfur, covellite, chalcocite and jarosite, contribute to the passivation layer on the surface of chalcopyrite. Carneiro and Leão found the porosity of secondary phase layer was expanded when 0.5–2.0 M Na-chloride was added into the chalcopyrite Cyclopamine leaching solution. Liang et al. presented that the accumulation quantity of elemental sulfur was substantially reduced with 11 mM sodium Na-chloride in the chalcopyrite thermophilic bioleaching solution (65 °C) [140]. Cai et al. detected the production of the covellite in chloride leaching solution during the process of

chalcopyrite dissolution [162]. Cu+ is monovalent in the band structure PRKD3 of chalcopyrite and its dissolution could easily be elevated by the formation of soluble Cu+–Cl− complexes. The impact of chloride on the growth of bioleaching strains has been broadly reported, such as A. ferrooxidans, L. ferriphilum, S. metallicus, S. rivotincti [163] and a mixed mesophilic culture [164]. It was obviously detected that a certain amount of chloride in the leaching solution would inhibit the growth of the iron-and sulfur-oxidizing microorganisms [165] and chloride toxicity to microorganisms displayed explicit differences and multiformities. Harahuc et al. presented that the growth of iron-grown Acidithiobacillus ferrooxidans was locally inhibited at the condition of 10 mM KCl and sulfur-grown bacteria could tolerate up to 200 mM [165]. Shiers et al. showed that concentrations of 7 g/L NaCl reduced cell replication by 50% and that no significant culture adaptation or habituation occurred with prolonged exposure to that concentration [164]. Deveci et al. reported that salinity in the range of 1–4% (NaCl w/v) was substantially detrimental to mesophilic bioleaching microorganisms [166]. Gahan et al. found that chloride at 4 g/L (110 mM) was lethal to a pyrite-oxidizing microbial consortium [167].