Improved gold diagnostic leaching procedure for carbonaceous preg-robbing ores

The article presents an improved procedure for the diagnostic leaching of gold in carbonaceous preg-robbing mineral ores. When researching highly preg-robbing ores, classic diagnostic gold leaching approaches often lead to distorted results: the proportion of cyanidable gold is underestimated, while recoverable gold is er roneously attributed to refractory forms. This discrepancy arises from the high natural sorption activity of organic carbon, which interferes with artificial sorbents at all leaching stages to competitively adsorb gold from the liquid phase of cyanide pulp. An advanced diagnostic two-stage leaching procedure for highly preg-robbing materials has been developed: first, cyanidation is carried out under standard conditions with an increased sorbent load, then high-temperature sorption processing at a temperature of 80–95°C for 2 hours is carried out with fresh sorbent. Tests carried out on various carbonaceous mineral products demonstrated improved gold recovery efficiency during cyanidation. The 4.2–12.5 % increase in obtained cyanidable gold as compared to the conventional method enables more precise differentiation of gold forms and optimization of processing strategies for preg-robbing ores. This pro cedure is particularly valuable for ores having a high organic carbon content and strong preg-robbing capacity due to providing more reliable phase characterization of gold and supporting accurate selection of processing technolo gies. The protocol is recommended for implementation in both laboratory and industrial practice.