Determination of Au and Ag from iron ores combining FA and ICP/AES methods

Abstract

In this paper, the combination of FA (Flame Analysis of Noble Metals - Cupellation) and ICP/AES (Atomic Emission Spectrometry with Induction Coupled Plasma) methods for determination of Au and Ag in geological samples of iron ore-magnetite was presented. Au and Ag were concentrated with Pb from PbO after desulphurisation and melting process (Pb2+→Pb). Regulus (Pb with noble metals) is then cupellated. The resulting bead-pril after cupellation was dissolved in HNO3 and then in HCl (imperial water: 2HNO3 and 6HCl). After the preparation of standard solutions and a blank test, the ICP/AES recording is performed. The obtained results were compared with those obtained by the classical method of cupellation. The advantages of ICP/AES are excellent detection limits and linear dynamic range as well as a stable and repeating signal which is particularly important for samples of iron tested due to the low content of noble metals.

U ovom radu je prikazana kombinacija FA (plamena analiza plemenitih metala-kupelacija) i ICP/AES (atomska emisiona spektrometrija sa indukovanom kuplovanom plazmom) metoda za određivanje Au i Ag u geološkim uzorcima rude gvožđa-magnetit. Au i Agse koncentišu sa Pb iz PbOnakon procesa odsumporavanja i topljenja (Pb2+→Pb).Regulus (Pb sa Au i Ag)se kupelira. Dobijena perla-pril nakon kupelacije se rastvara u HNO3 a zatim u HCl(carska voda 2HNO3: 6HCl). Nakon pripreme standardnih rastvora i blank probe vrši se snimanje na ICP/AES. Dobijeni rezultati su poređeni sa rezultatima dobijenim klasičnom metodom kupelacije. Prednosti ICP/AES su odlične granice detekcije i linearni dinamički opseg kao i stabilan i ponovljiv signal što je posebno bitno za uzorke ispitivane rude gvožđa zbog malog sadržaja plemenitih metala.