Barrick Gold has been granted a patent for a gold recovery process that uses activated carbon to accelerate thiosulfate leaching of gold from a gold-bearing material. The process involves contacting the precious metal-bearing material with activated carbon, thiosulfate, an anion exchange resin, and an oxidant to form a slurry, and then leaching the precious metal from the slurry. The process does not require the addition of copper and has shown improved gold recovery compared to traditional methods. GlobalData’s report on Barrick Gold gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Barrick Gold, extraction by leaching was a key innovation area identified from patents. Barrick Gold's grant share as of June 2023 was 1%. Grant share is based on the ratio of number of grants to total number of patents.
Gold recovery process using activated carbon for thiosulfate leaching
A recently granted patent (Publication Number: US11639540B2) describes a process for leaching precious metals from a precious metal-bearing material using a particulate carbon-based material, thiosulfate, an anion exchange resin, and an oxidant. The process involves contacting the precious metal-bearing material with the particulate carbon-based material, thiosulfate, an anion exchange resin, and an oxidant to form a slurry. The weight ratio of the precious metal-bearing material to the particulate carbon-based material is more than 125:1. The slurry is then leached to extract the precious metal, resulting in a leached precious metal-bearing material and leached precious metal. The anion exchange resin has a greater affinity for the leached precious metal than the particulate carbon-based material. The process is performed in the substantial absence of added copper.
The patent also discloses variations of the process, including the use of a gold-bearing material instead of a precious metal-bearing material. In this case, the gold-bearing material is contacted with a carbon-based material, thiosulfate, and an anion exchange resin to form a slurry. The slurry is then contacted with an oxidant to leach gold from the gold-bearing material and deposit the leached gold onto the anion exchange resin. The process also involves removing the carbon-based material from the leached gold-bearing material.
The described processes offer a novel approach to leaching precious metals, such as gold, from various materials. The use of a particulate carbon-based material, thiosulfate, an anion exchange resin, and an oxidant allows for efficient extraction of precious metals while minimizing the need for added copper. The processes can be applied to a range of materials, including oxide ores, and can be performed without the need for pretreatment of the precious metal-bearing material. The patent provides specific details regarding the conditions and parameters for optimal leaching, such as pH, thiosulfate concentration, and oxidation-reduction potential.
Overall, the granted patent presents a promising method for the extraction of precious metals from various materials, offering potential benefits in terms of efficiency and environmental impact.