[en] The principles are presented of the radioisotope tracer methods applied to the study of efficiency and kinetics of hydrometallurgic processes of leaching and liquid extraction and also to the study of the hydrodynamics of hydrometallurgic apparatus. These methods were applied in the investigations of the hydrometallurgical processing of materials from the copper industry and to the hydrodynamics of various types of leaching apparatus and of a bath for copper electrorefining. (author)

No abstract available

[en] The solvent extraction of molybdenum(VI) from sulphuric acid solutions with di-(2-ethylhexyl)-phosphoric acid (HDEHP) and monododecylphosphoric acid (HDDP) in n-heptane has been studied (a) as a function of the concentration of sulphuric acid, molybdenum and the extractant; (b) in the presence of copper and zinc in the aqueous phase and (c) in the presence of tri-n-butylphosphate (TBP) in the organic phase. The distribution of the sulphuric acid between aqueous and organic phase has also been studied. The results obtained fail to provide evidence on whether extraction of sulphate complexes of molybdenum is possible in the system studied because of the lack of correlation between the extraction of molybdenum and of sulphuric acid, and the occurrence of the competition. It seems likely that from concentrated solutions of sulphuric acid molybdenum is extracted in the form of molybdenic acid associates. (T.G.)

[en] A method was developed and introduced for monitoring the movement of silver-containing anodic slimes in copper electrorefining baths. Radioactive ¹¹¹Ag was used as tracer and copper plates labelled with the tracer were inserted into the anodes. During electrorefining the slime produced was continuously marked by the tracer. The activity of ¹¹¹Ag was measured at various points inside the bath by sampling and continuously registered with the aid of integrators. It was found that more than 99 percent of the slime slipped to the bottom of the bath close to the anode surface and did not migrate even at highest electrolyte flow rates. Small quantities of suspended slime contained an insignificant concentration of silver and should not be a source of cathode contamination. (author)