TY - JOUR
T1 - Recovery of precious metals using nickel sulfide fire assay collection
T2 - Problems at nanogram per gram concentrations
AU - Frimpong, A.
AU - Fryer, B. J.
AU - Longerich, H. P.
AU - Chen, Z.
AU - Jackson, S. E.
PY - 1995
Y1 - 1995
N2 - The NiS fire assay is widely used for the separation and concentration of PGE and Au from geological materials. The effect of collector mass on the recovery of PGE and Au in a Pt ore grade (μg g-1) sample and a komatiite sample which contained <10 ng g-1 of PGE are reported. The PGE and Au recoveries were not a function of collector mass for the ore grade sample. The recovery of Ir, Os and Au from the komatiite sample did not significantly depend on the mass of the collector used but Ru, Rh, Pd, and Pt recoveries were reproducible and dependent upon the collector mass. From these recoveries, estimates of the partition coefficients (Kd) were calculated for the sulfide and silicate melt phases. The Kd values were also estimated from direct analysis of the two phases. The recoveries of the precious metals were not always independent of the collector-to-flux-ratio. Also, the Kd values were found to depend upon the PGE concentrations. The Kd values obtained for an ore-grade sample were 4 to 103-fold higher than those obtained for a sample which contained < 10 ng g -1 PGE concentrations. Thus, when determining PGE concentrations at low levels using NiS fire assay collection, significant biases may occur.
AB - The NiS fire assay is widely used for the separation and concentration of PGE and Au from geological materials. The effect of collector mass on the recovery of PGE and Au in a Pt ore grade (μg g-1) sample and a komatiite sample which contained <10 ng g-1 of PGE are reported. The PGE and Au recoveries were not a function of collector mass for the ore grade sample. The recovery of Ir, Os and Au from the komatiite sample did not significantly depend on the mass of the collector used but Ru, Rh, Pd, and Pt recoveries were reproducible and dependent upon the collector mass. From these recoveries, estimates of the partition coefficients (Kd) were calculated for the sulfide and silicate melt phases. The Kd values were also estimated from direct analysis of the two phases. The recoveries of the precious metals were not always independent of the collector-to-flux-ratio. Also, the Kd values were found to depend upon the PGE concentrations. The Kd values obtained for an ore-grade sample were 4 to 103-fold higher than those obtained for a sample which contained < 10 ng g -1 PGE concentrations. Thus, when determining PGE concentrations at low levels using NiS fire assay collection, significant biases may occur.
KW - Inductively coupled plasma mass spectrometry
KW - Nickel sulfide fire assay
KW - Partition coefficient
KW - Platinum group element
KW - Precious metal
UR - http://www.scopus.com/inward/record.url?scp=0000910804&partnerID=8YFLogxK
U2 - 10.1039/AN9952001675
DO - 10.1039/AN9952001675
M3 - Article
AN - SCOPUS:0000910804
SN - 0003-2654
VL - 120
SP - 1675
EP - 1680
JO - The Analyst
JF - The Analyst
IS - 6
ER -