Comparison of Recoveries by Lead Fire Assay and Nickel Sulfide Fire Assay in the Determination of Gold/ Platinum/ Palladium and Rhenium in Sulfide Ore Samples

Abstract

We compared the recovery of gold, palladium and platinum by two fire assaying procedures, using nickel sulfide and lead as collectors. The presence of appreciable amounts of sulfide minerals in the sample caused interferences in both procedures. An in‐house reference sample, a reference sample of high‐grade sulfide ore and samples of high sulfide content from the Recsk porphyry copper ore in Hungary were analysed by both methods. The elements were determined by inductively coupled plasma‐atomic emission (ICP‐AES) and/or inductively coupled plasma‐mass spectrometry (ICP‐MS). It was found that for the sulfide ore samples, the recoveries of Au and Pd are sometimes lower by nickel sulfide fire assay than by lead fire assay. Recovery of Re by nickel sulfide fire assay was found to be low: the average recovery of five repeated analyses of the reference sample NIST SRM 330 was 9% with a relative standard deviation of 48%. Increasing the amount of S in the fusion flux gave better recovery.

Comparison between Nickel‐Sulfur Fire Assay Te Co‐precipitation and Isotope Dilution with High‐Pressure Asher Acid Digestion for the Determination of Platinum‐Group Elements, Rhenium and Gold

“…This, coupled with past results, suggests that the presence of a high sulfur concentration in the sample increases the total Re recovery, but that it always remains incomplete. Juvonen et al (2004) also found that adding extra sulfur will increase Re recovery. However, the authors do not recommend this technique to separate Re before determination.…”

Sample Digestion and Combined Preconcentration Methods for the Determination of Ultra-Low Gold Levels in Rocks

“…NiS-FA can be used to collect both PGEs and gold, but its efficiency for gold determination has been very low. Juvonen et al [40] compared NiS-FA with Pb-FA in terms of their collection efficiencies of Au, Pt, Pd, and Rh and found that the gold recovery of NiS-FA was twice as low as that of Pb-FA at low gold concentrations. Plessen and Erzinger [41] reported that the gold recovery did not exceed 70% when NiS-FA was used to analyze rocks.…”

Investigation of Iron Matte Containing PGMs Leaching under Oxidative Conditions

“…Literatürde yayınlanan son çalışmalarda PGM'lerin çeşitli endüstriyel proseslerden elde edilen matlarda zenginleştirilmesi ve bu matların çözümlendirilme şartlarının belirlenmesi üzerine araştırmalar yapılmıştır. Örneğin; Ni-Cu-Fe-S Peirce Smith konvertör matı; Ni-Cu konvertör matı; Ausmelt yöntemi konvertör matlarının çeşitli şartlarda farklı çözücüler varlığında çözümlendirilmesi incelenmiş ve PGM'lerin geri kazanımı üzerine bir dizi çalışmalar yürütülmüştür [24][25][26]. Fakat bu çalışmalar genellikle sülfürlü cevherlerde var olan PGM'lerin geri kazanımı üzerine gerçekleştirilmiştir.…”

“…bulunan platin grubu metallerin çeşitli spektroskopik yöntemle analizleri hakkındadır. Bu çalışmalarda genellikle spektroskopik teknikler karşılaştırılmış ve karşılaşılan sorunlar için alınması gereken önlemler araştırılmıştır [23,24]. NiS matı yönteminin katalitik dönüştürücüler kullanılarak reaksiyon şartlarının belirlenmesine yönelik gerçekleştirilen çalışmada %99'a yakın PGM geri kazanım elde edilmiş fakat PGM'lerin çözeltiye alındıktan sonra selektif olarak çöktürülmesi, daha sonra çözeltideki nikelin tekrardan kazanılarak yöntemde kullanımı hakkında çalışmalar eksik kalmıştır [4].…”