Au-Ag noble metal wastes represent a wide range of waste types and forms with various ballast elements and components. The thiourea process of gold and silver extraction from ores, concentrates or secondary raw materials consists of gold and silver leaching into the thiourea solution and the consequent precipitation of these metals from the solution. Due to the non-toxic character of thiourea i...

Purpose. Research on the process intensification of gold-bearing product hydrometallurgical processing based mechanochemical milling initial sulphide material. Methods. Mechanochemical activating (oxidation) concentrate under conditions superfine milling, sulphite-thiosulphate leaching milled after liquid phase separation. The float sample with a particle size -0.074 mm, Au content is 15.5 g/t ...

This paper reports on the recovery of zinc, cobalt and manganese by two-step leaching of zinc-plants purification residue with sulfuric acid. The residue, hot filter press cake (HFC), contains 14 % ZnO, 4.8 % Co3O4 and 22.9 % MnO. Effects of different parameters are determined and used to optimize the process. With acid to hot filter press cake (HFC) stoichiometry of 0.85, acid concentration of...

In this paper, the leaching behavior of the major metals present in printed circuit boards waste is evaluated, aiming at its recycling by hydrometallurgy. Several leachants were compared (sulfuric, hydrochloric and nitric acids, at 2 M H concentration), at temperatures of 25oC and 90oC and 4 hours of reaction time. Sulfuric acid leaching was not very promising concerning metals dissolution bein...

In this paper, the extraction of vanadium from stone coal by roasting with MgO and leaching with sulfuric acid has been investigated, and the mechanism analysis of stone coal roasting with MgO was studied. The results indicated that under the conditions that the mass fraction of the particles with grain size of 0–0.074 mm in raw ore was 75%, the roasting temperature was 500 ◦C, the roasting tim...