Of global gold reserves, 24% are high-grade refractory gold deposits. These deposits also account for 22% of all the world’s gold.

Extracting and processing gold from refractory gold ores is both more complex and more expensive, as it involves specialised pretreatment methods such as bio-oxidation, pressure oxidation (POX), ultrafine grinding, and roasting.

These extra steps and the equipment needed for these processes add to the costs of processing refractory gold ores. Yet with global gold reserves dwindling, miners are increasingly having to source it from refractory deposits.

However, despite the high costs involved in extracting gold from high-grade refractory deposits, they hold the potential of costing less per ounce than nonrefractory types, according to a publication this year from McKinsey and Company.

Production from refractory ores is also predicted to grow at a faster rate (1.4%) over the next four years than production from nonrefractory deposits (which it is estimated will grow by only 0.3%). This is due to the fact refractory ores have an 86% higher grade on average than nonrefractory gold reserves. These notably higher grades offset the high operational costs of processing them.

The author of the McKinsey and Company article identifies three key approaches mining companies can use to get the most out of refractory gold ore mining.

Three ways miners can maximise the benefits of refractory gold ore mining:

  1. Using digital technologies to optimise the rate of production and yield through operations and alleviate the costs involved, such as artificial intelligence systems specially created to boost the performance of a plant.
  2.  Mining companies that own refractory ore processing units would have the ability to process not just their own refractory deposits, but also those of other miners with mine sites in different locations that do not have their own refractory processing plants. These third-party miners can transport their ore to these plants for processing where there is extra capacity, increasing general production of refractory ores.
  3. Designing plants and mines for refractory ore mining must be done carefully and thoughtfully in a way that allows miners to stay on budget with capital expenditure (capex) and operational expenditure (opex) when producing gold from refractory ores. Optimising the mine plan will save miners costs in the long run.

In conclusion

If mining companies worldwide can implement these approaches, refractory gold deposit processing can increase as a practice, boosting gold production and mitigating the costs involved. This would be a good solution to the current gold reserve shortage.

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