On-site oxygen generators for mining

Where mineral processing uses oxygen

• Cyanide leaching of gold: both oxygen and cyanide are required to dissolve the gold, and with cyanide typically in excess, oxygen is the rate-limiting reactant (Eriez, 2020). See oxygen for gold leaching.
• Pre-aeration: a 1992 review by K. E. Haque reports that preaerating the slurry with air or oxygen alleviates the effects of soluble sulphides, arsenates and antimonates on cyanidation.
• Refractory ores: where gold is occluded in sulphides, silicates or tellurides, Haque notes that it can be liberated by roasting in the presence of oxygen or by leaching under oxygen pressure.
• Oxidation and cyanide destruction: Eriez lists pre-aeration, oxidation, leaching and cyanide destruction among the processes that use gas sparging, with air, oxygen-enriched air or high-purity oxygen.

An example from a gold mine

A March 2019 Cyanide Code recertification audit of one gold mine records two PSA oxygen generators producing about 8 tonnes of oxygen a day at 92% purity to supply its CIL tanks, where an average dissolved oxygen of about 24 ppm was maintained in the first two leach tanks.

Points to weigh at a mine site

• Altitude: WHO's Foundations of medical oxygen systems (2023) says VSA operation is less affected by altitude, and PATH and CHAI (2021) say VSA plants can operate at higher altitudes without a reduction in performance.
• Humidity: WHO reports higher VSA efficiency in humid environments, which it attributes to VSA not needing an air dryer.
• Pressure: VSA plants produce oxygen at a much lower pressure than PSA plants and often need an additional high-pressure oxygen compressor (PATH and CHAI).
• Service: UNDP (2025) notes that VSA and VPSA need oil-free booster compressors and specialised maintenance tools, with limited spare parts and support in many regions, and a Global Fund note (4 March 2025) advises choosing the technology already common and functional in the region.
• Air or oxygen: Eriez notes that site-specific considerations sometimes make air the preferred sparging gas.

The WHO, PATH, UNDP and Global Fund documents cited here were written for medical oxygen plants.

ULTRAOX VSA for mine sites

ULTRAOX VSA, the Ultra Controlo industrial oxygen plant, lists gold leaching in mines among its applications, alongside wastewater treatment, hydrogen sulphide (H2S) reduction and industrial furnaces. It delivers 75% to 95% oxygen at 50 kPa, with an additional oxygen booster for higher pressures; it is supplied on a skid or in a container; and it can replace cryogenic systems with liquid oxygen tanks or work as the main source of supply. The datasheet describes a totally oil-free production system and a life cycle calculated for 150,000 hours, and bases its performance data on 15 °C and 40% relative humidity. See industrial oxygen generators: PSA and VSA for the model range.