Gold Diagnostic Leach Test
Assessing the deportment of gold to certain mineral classes can be performed using a diagnostic leach test. By understanding the nature of gold deportment a good view of the likely required process 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.
The attack stages available and the form of gold liberated is given below
||Minerals Likely to be Destroyed
||Free, Liberated, Exposed Gold
||Gypsum and Arsenates
||Pyrrhotite, Calcite, Dolomite, Galena, Goethite, Calcium carbonate
||Calcine, Haematite, Ferrites
||Uraninite, Sphalerite, Labile Copper Sulphides, Labile Base Metal Sulphides, Labile Pyrite
||Sphalerite, Galena, Labile Sulphides, Tetrahedrite, Sulphide Concentrates
||Pyrite, Arsenopyrite, Marcasite
|Oxalic Acid Washes