Bulk leach extractable gold (BLEG) was developed in the 1980s to reduce the impact of nuggety gold. Today, it can be used in exploration for trace gold determinations to provide robust, consistent results. The large sample size utilised can help decrease the influence of coarse gold making results more reproducible. Samples from areas with coarse gold, can use BLEG paired with AAS or ICP-MS finish to report reproducible low-level results.
For BLEG analysis, samples up to 3kg are treated with cyanide solution and rolled to increase the interaction between the reagent and sample. Even with agitation, gold encapsulated in silica, or very large Au grains may not be fully dissolved by BLEG methods (Hoffman,et al., 1998).
Code | Analyte | Range (ppm) | Description |
---|---|---|---|
Au-CN12* Au-AA12** |
Au | 0.0001-10 | BLEG – ICP-MS finish. BLEG – extraction AA finish. Up to 1kg sample |
Au-CN11* Au-AA11 |
Au | 0.001-50 0.001-10 |
BLEG – ICP-MS finish. BLEG – extraction AA finish. Up to 500g sample |
Au-AA15a Au-AA15b Au-AA15c Au-AA15d |
Au | 0.001-125 | Au by accelerated cyanide leach using LeachWELL Assay Tabs™ with AAS finish. 4hr Leach. 500g sample request Au-AA15a For 1kg request Au-AA15b For 2kg request Au-AA15c For 3kg request Au-AA15d |