Keywords

Fire Assay



Keyword Definition

Fire assay is commonly used to determine gold, silver, platinum and palladium.

Fire assaying involves the fusion of a mixture of sample (5-100 g) and borate flux in a fireclay crucible.  On fusing, the sample matrix dissovles in a borax slag; the noble metals are strongly partitioned into an immiscible collector phase which settles to the base of the crucible.  Collector phases include lead, nickel sulphide, copper sulphide, tin and silver.

Historically, the crucible was called a cupel, and the process is referred to as cupellation.

After cupellation, the sample may undergo further processing (e.g. dissolution in aqua regia), depending on the details of the analytical procedure.



Hierarchical classification

Decomposition >> Fusion >> Fire Assay

Children

Pb | PbO/Ag | NiS


Category: Decomposition techniques

The different kinds of analytical decompositions have been classified hierarchically. Examples: “fusion”, “acid” Taken from the “Analytical_Decompositions_SHARED” database table.


Associated Analytical Suites:

IndexSuite IDSuite Name
1  33     Chemex Au FA-NA (till, Mississauga)
2  82     Bondar-Clegg Au FA-AAS
3  83     Chemex Au FA-AAS
4  101     ActLabs 1A2 Au Fire Assay AAS
5  121     Chemex FA-AFS (Au, Pt, Pd)
6  122     Bondar-Clegg Au FA-NA
7  136     Chemex FA-ICPES (Au, Pt, Pd)
8  332     ActLabs 1C-EXP2: Fire assay – ICP-MS
9  415     Novatrack Analysts Limited (lake sediments) Au + Wt (variable d.l.= 1  for 10 g sample or 2 ppm for 5 g sample)
10  421     Chemex (lake and stream sediment) FA-NA (Au) + Wt -Au (variable d.l.= 1  for 10g sample or 2 ppm for 5g sample)
11  524     Cantech (stream sediment) FA/ICP-MS (Pt, Pd)
12  621     Geoscience Lab, (OGS) MRD123 Lithogeochemical Database: silver FA ICP-AES
13  624     ActLabs 1A3-Ag: Au, Ag Fire Assay - Gravimetric
14  678     NGR BC Au, Ag FA-AAS
15  679     NGR BC Au FA-AAS

Associated Analytical Packages:

IndexPackage IDPackage Name
1  15     Chemex AAS (As) + FA-NA (Au)
2  19     Chemex AAS (As, Sb, Bi) + Hg CV-AAS + FA-NA (Au)
3  21     Chemex AAS (As, Sb) + Hg CV-AAS + FA-NA (Au)
4  23     Chemex AAS (Ag, As, Sb) + Hg CV-AAS + FA-NA (Au)
5  53     Bondar Clegg Au FA-AAS
6  54     Chemex Au FA-AAS
7  59     Chemex Au FA-NA
8  62     Chemex Au + Nb
9  78     Chemex Au-AFS, As-AAS, Pt, Pd
10  79     Bondar Clegg Au FA-NA
11  88     Chemex FA-ICPES (Au, Pt, Pd)
12  104     OGS / MRD123 miscellaneous methods
13  296     ActLabs GSC TGI4 whole rock analysis (variant #1)
14  297     ActLabs GSC TGI4 whole rock analysis (variant #2)
15  298     ActLabs GSC TGI4 whole rock analysis (variant #3)
16  310     Chemex (NGR BC stream sediment and moss mat samples, 1988)
17  311     Barringer Magenta (NGR BC stream sediment and moss mat samples, 1989)
18  312     Barringer Magenta fire assay (Au) and weight
19  395     Novatrack Analysts Ltd (NGR lake sediment) fire assay (Au) + Wt
20  399     Chemex (NGR lake or stream sediment) fire assay (Au) and weight
21  475     Cantech (NGR stream sediment)  AAS(8+4), CV(Hg), LOI, F, FA/ICP-MS (Pt, Pd) F
22  500     ActLabs 1H (Au+48) and 1C-EXP2 (Au, Pt, Pd)
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