Gold mines across sub-Saharan Africa are seeing transformational results by switching from delivered oxygen to on-site oxygen generation for gold mining. According to David Kempe, Commercial Director at O₂Africa, some mines are saving as much as 70% in operational costs, while also improving recovery rates and reducing their environmental footprint.

At the core of this shift is O₂Africa’s Pressure Swing Adsorption (PSA) technology. Designed to produce high-purity oxygen directly at the mine site, the PSA system eliminates the logistical burden of deliveries and enables more precise control over oxygen supply.

“Our PSA systems use zeolite to separate oxygen from the air,” explains Kempe. “This guarantees a steady, cost-effective, and reliable oxygen supply—especially critical for remote sites where delivery delays are common.”

This continuous supply plays a pivotal role in gold processing. Oxygen is introduced during the carbon-in-leach (CIL) or carbon-in-pulp (CIP) stages, where it improves leaching kinetics, reduces cyanide usage, and ultimately increases the gold recovery rate. Mines benefit not only from higher yields but also from reduced chemical use and shorter processing cycles.

“Consistent oxygen flow is fundamental for efficient gold extraction,” adds Kempe. “With direct control over flow rate and purity, our systems deliver faster leaching, greater recovery, and fewer environmental risks.”

In gold mining, leaching refers to the process of dissolving gold from the ore using a chemical solution. Typically, a cyanide solution is used to separate the gold from the surrounding rock. Oxygen plays a critical role in this process by enhancing the chemical reaction between cyanide and gold, allowing for faster and more complete extraction. This is most commonly applied in methods like carbon-in-leach (CIL) and carbon-in-pulp (CIP), where finely ground ore is mixed with the solution and activated carbon to absorb the dissolved gold.

By introducing high-purity oxygen into the leaching tanks, PSA systems significantly improve the reaction kinetics, which means gold is extracted more quickly and with higher yield. This also allows for lower cyanide consumption, reducing both operational costs and environmental risks.

Beyond leaching, PSA systems bring additional value to mining operations. They are also used in wastewater treatment, where oxygen supports the biological breakdown of contaminants, and in oxygen-enriched combustion during smelting and refining, which improves energy efficiency and reduces harmful emissions.

This versatility makes PSA technology a valuable asset across multiple stages of the gold production process, not just in leaching but in downstream and auxiliary applications as well.

Adopting on-site oxygen generation for gold mining offers immediate and measurable environmental improvements for mining operations. One of the most significant changes is the reduction in transport-related emissions. Traditionally, oxygen is delivered by truck, often over long distances to remote sites. Each delivery increases the mine’s carbon footprint through fuel consumption, road wear, and packaging waste. By generating oxygen directly at the site, mines can eliminate this logistical burden, lowering emissions and reducing their reliance on fossil fuels.

On-site generation also contributes to cleaner processing. High-purity oxygen improves the efficiency of the gold leaching process, which allows mines to use less cyanide to achieve the same extraction results. Cyanide is a toxic chemical, and using less of it means reducing the risks associated with handling, storage, and waste management. The result is less hazardous waste, simpler tailings treatment, and fewer risks to the environment and worker safety.

Additionally, improved leaching efficiency can lead to shorter retention times in process tanks. This not only increases throughput but also reduces the amount of water required, enabling better water recycling and more sustainable water usage overall. In parallel, PSA systems support effective wastewater treatment by enhancing the biological breakdown of contaminants, which is particularly valuable in regions with limited water resources.

From an operational perspective, PSA systems provide consistent control over oxygen purity and flow rate. This level of control enhances overall process performance, increases gold recovery, and reduces downtime. Mines are able to fine-tune their oxygen supply to match production needs without waiting on external suppliers.

“Our technology helps mining operations become more environmentally responsible without increasing operational complexity,” says David Kempe, Commercial Director at O₂Africa. “This approach aligns with growing global expectations around sustainability and responsible sourcing.”

By switching to PSA systems, mines are not only cutting emissions and improving efficiency but also demonstrating their commitment to responsible practices. This

supports compliance with Environmental, Social and Governance (ESG) standards, which are increasingly important to investors, regulators, and global supply chains.

O₂Africa’s oxygen generation systems are not only engineered for performance but also represent a strong commitment to local innovation and economic development. Every system is designed and manufactured in South Africa, drawing on local expertise, suppliers, and engineering talent. This approach ensures that the technology is fully adapted to the specific challenges of African mining environments, including variable infrastructure, remote locations, and fluctuating power conditions.

By building its solutions locally, O₂Africa contributes directly to South Africa’s industrial development and job creation efforts. The company invests in skilled trades, technical training, and engineering partnerships within the country, helping to strengthen the local manufacturing base while also delivering world-class equipment.

“This is a solution created in South Africa, for African mines,” says David Kempe, Commercial Director at O₂Africa. “We’re proud to play a role in the region’s industrial transformation, not just by improving mining operations but by supporting local industries and boosting employment.”

In choosing O₂Africa, mining companies are not only investing in reliable oxygen supply but also contributing to a broader ecosystem of African-made innovation, technical advancement, and economic resilience. The result is a supply chain that is shorter, faster, and more responsive to local needs, backed by people who understand the terrain and the industry firsthand.

Kempe acknowledges that adoption hasn’t been without its challenges. Initial resistance to change and a lack of familiarity with PSA systems have been obstacles. O₂Africa addresses these by:

• Training operational teams to manage systems independently
• Implementing redundancy and power-stabilization measures
• Providing ongoing engineering support and responsive maintenance services

“Training is essential,” says Kempe. “We want mines to be self-sufficient and confident in running their own oxygen systems.”

The results speak for themselves. Mining operations in South Africa, Ghana, and Guinea have already adopted O₂Africa’s PSA technology, with some combining on-site oxygen generation for gold mining with traditional delivery to cover peak-demand periods.

“This hybrid approach gives mines greater flexibility and resilience,” says Kempe. “They can respond to changing conditions without jeopardizing production.”

To support this flexibility, O₂Africa is also developing smart monitoring capabilities that allow mines to track oxygen usage in real time, schedule proactive maintenance, and minimize unplanned downtime.

With local manufacturing, expert support, and a clear ROI, O₂Africa’s PSA solutions are helping gold mines enhance recovery, reduce costs, and build more sustainable operations.

“Our mission is to help mines produce gold more efficiently, with less waste and greater financial returns, for stakeholders and the communities around them,” Kempe concludes.