Estimation of valuable metals content in tin ore mining waste of the Russian Far East region by instrumental neutron activation analysis

Abstract Wastes from tin sulfide ore mining can serve as a secondary raw materials for obtaining rare and rare-earth elements (REE). This work demonstrates the possibility of effectively using instrumental neutron activation analysis (INAA) with a 252 Cf radionuclide source to determine the content of Sc, In and a number of REE content in tailings from tin sulfide ores and monominerallic samples of various compositions. For samples with volumes of 50 cm 3 , with the activation time of 7 days and the measurement time of 1–2 h, the calculated Minimum Detectable Concentrations are sufficient for the quantitative determination of Sc and REE (La, Sm, Eu) below the average upper continental crust concentration (UCC). Elevated levels of strategic metals were detected in samples collected from the tailings dump of the Khrustalnensky Mining and Processing Plant (KhGOK) in Kavalerovo District and the tailings dump of the Krasnorechenskaya Concentrating Mill (KCM) in Dalnegorsk District of the Primorsky Krai, Russia. Elevated concentrations of Sc (2.1 times UCC) and In (1.8 times UCC) were detected in the tailings sample after cassiterite secondary enrichment. A decrease in Sc concentration was detected in the upper layer of the KhGOK tailings dump. Increased In content 141–575 times UCC was detected in tailings samples from KCM. Conducted analyses show the prospects of processing the KCM tailings enrichment for indium by-product recovery. INAA could be applied both to assess the reserves of some valuable metals and develop the technology of their extraction.