By understanding the nature of gold deportment with a Gold Diagnostic Leach the likely processing method can be gained early on in flowsheet development. The test can also be applied to process feed streams to troubleshoot reasons for low gold recoveries in an operating environment.
The test works by selectively leaching gold carrier minerals one group at a time and then using a cyanidation leach to recover the gold liberated from those phases.
GSL offers the following gold diagnostic attacks:
|Treatment Step||Minerals Likely to be Destroyed|
|NaCN Wash||Precipitated Gold|
|NaCN||Free, Liberated, Exposed Gold|
|Na2CO3||Gypsum and Arsenates|
|HCl||Pyrrhotite, Calcite, Dolomite, Galena, Goethite, Calcium carbonate|
|HCl/SnCl2||Calcine, Haematite, Ferrites|
|H2SO4||Uraninite, Sphalerite, Labile Copper Sulphides, Labile Base Metal Sulphides, Labile Pyrite|
|FeCl3||Sphalerite, Galena, Labile Sulphides, Tetrahedrite, Sulphide Concentrates|
|HNO3||Pyrite, Arsenopyrite, Marcasite|
|Oxalic Acid Washes||Oxide Coatings|