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The use of radiotracers in the present study is intended to replace traditional steps of metal quantitative analysis (solution sampling and instrumental chemical analysis) and to allow real-time measurements of metal concentrations during the leaching process. In this study, 64Cu, an isotope of copper, was selected as a radiotracer. Samples of copper flotation tailings were irradiated in the Maria research reactor (Świerk, Poland) and mixed with an inactive portion of the milled fl otation waste. The leaching process was carried out in a glass reactor, and the radiation spectrum was measured using a gamma spectrometer. The material was then treated using various acids (sulphuric acid, nitric acid, acetic acid, citric acid, and ascorbic acid) in a wide range of their concentrations. Experiments with the radiotracer were conducted in sulphuric and nitric acids. The amount of the leached metal (copper) was calculated on the basis of the peak area ratio in the gamma-ray spectrum of the activated tailings and standard samples. Inductively coupled plasma mass spectrometry (ICP-MS) was also used to analyse the metal content. Maximum recovery of 56% Cu was achieved using 9 M HNO3, whereas the recovery was lowest for ascorbic acid (<1%). Both analytical methods were compared, and the results presented in this paper are in good agreement with radiometric measurements obtained using ICP-MS analysis.

Scientifi c objective of this work was elaboration of radiometric method for the development of hydrometallurgical process for recovery of Cu from the copper ore. A neutron activation analysis (NAA) was identifi ed as a very convenient tool for the process investigation. The samples of copper ore were activated in a nuclear reactor. The parameters of the neutron activation were calculated. Radioisotope 64 Cu was selected as an optimal tracer, and it was used for the investigation of the leaching process. During the experiments, various processes applying leaching media such as sulphuric acid, nitric acid, and organic acids were investigated. The recovery of the metals using sulphuric acid was insuffi cient, around 10%. Investigated organic media also did not meet expectations. The best results were obtained in experiments with nitric acid. Up to 90% of Cu and other metals were extracted from the copper ore. Copper concentration calculations obtained by NAA were confi rmed by inductively coupled plasma mass spectrometry (ICP-MS) technique. Both techniques gave comparable results, but the advantage of the NAA is a possibility for easy online measurements without shutting down or disturbing the system.

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