Factors-Affecting-Cupellation-Loss-for-Gold-and-Silver-Milligram-Beads-from-Low-Grade-Material-AR25.pdf

1、 Copyright 2019 Rand Refinery confidentialSensitivity Label:Confidential-Rand Refinery Confidential InformationCUPELLATION LOSS FOR GOLD AND SILVER MILLIGRAM BEADS FROM LOW GRADE MATERIALMADELEINE THERON18 MARCH 20252SMELTER PROCESSP PROCESSROCESSSingle site Refinery and Smelter process100 different

2、 type of material throughputGold range 1 to 15 000 g/tSilver range 1 to 27 000 g/tPhysical Sample throughput 10 000 due to dual stream analysis3 Copyright 2019 Rand Refinery confidentialSensitivity Label:Confidential-Rand Refinery Confidential InformationOVERVIEWPublications since 1940Used synthetic

3、 gold and silver alloysSynthetic alloy use not always feasible due to costs and time Controlling factors in the assay of silver by cupellation,Controlling factors in the assay of silver by cupellation,C.W RellyC.W Relly (1940)(1940)An evaluation of the accuracy of the fire assay process when applied

4、 to the assay of low value residue samples,W.A Sinclair(1964)The determination of gold losses in the fire assay method,Siegfried Gerhard Wall(1972)The determination of losses in the fire assay of gold The determination of losses in the fire assay of gold cupellation and parting losses(1973)cupellati

5、on and parting losses(1973)A manual on fire assaying and determination of the noble metals in geological materials,V.E McKelvey,director(1977)Assay and analytical practice in South African mining industry,W.C Lenahan&R.de L.Murray-Smith(1985)The experience of cupellation in fire assay analysis,Decen

6、t Group(2021)4CUPELLATION PROCESS Heating the sample inside preheated cupels Main goal-separate precious metals from lead Lead oxidized to molten litharge Molten precious metals not absorbed Base metals absorbed by the cupel Gold and other noble metals-bead5 Silver is more rapidly oxidized than gold