Product story

Cryogenic perlite meets urgent medical oxygen bottles need in Brazil state ravaged by COVID-19

With a desperate lack of healthcare supplies for Covid-19 patients in Brazil’s largest state, Imerys produced and delivered 3.3 tonnes of cryogenic perlite that was essential for safeguarding bottles of medicinal oxygen at the right temperature.

Cryogenic perlite

In Amazonas, a state in the North of Brazil, a devastating surge in Covid-19 cases at the beginning of 2021 led to a dramatic increase in the daily consumption of medicinal oxygen in the region.

Hospitals and emergency services have been struggling to cope with the virus, and the state governor Wilson Lima described the escalation of infections as “the most critical moment of the pandemic, something unprecedented in the state of Amazonas”.

Quick response to provide medical supplies during Covid-19 crisis

Imerys worked quickly with one of its customers, a manufacturer of industrial and medicinal gases, to deliver the urgently needed supplies, once again demonstrating the essential importance of minerals during the pandemic. Cryogenic material – produced at Imerys’ Paulínia site in São Paulo – is a fundamental element in the production, transportation and conservation of oxygen. 

In less than half a day, Imerys’ Paulínia plant produced 60m³ of cryogenic perlite, which was transported to Manaus by Brazilian Air Force planes. 

How is cryogenic perlite used for the safe storage and transport of oxygen?

Atmospheric air is composed of nitrogen and oxygen, and is the raw material for cryogenic distillation. By compression and then cooling of this air to very low temperatures (below -150°C), the oxygen is liquified and separated.

Thermal insulation is essential for its safe storage and transport. Cryogenic perlite – an expanded form of the perlite rock – has low thermal conductivity and is non-combustible, making it ideal for the storage of liquid gases at -270°C. Filling the space between the double walls of tanks and vessels that contain the oxygen, it helps liquid gases keep their temperature.

Cryogenic perlite has the best relation benefit/cost, and John Alexander Gil Vega from Imerys’ Technical Expert team, explains Imerys’ ore and expansion process.

“The crushed perlite rock is quickly heated in a vertical furnace to a temperature above 1,000°C, at which point it begins to soften to a plastic state where the entrapped combined water vaporizes. This thermal process causes the material to expand. Perlite can grow up to 15 or 20 times its original volume and has a bulk density from 50 to 120 kg/m³. The cryogenic perlite produced at the Paulínia plant has a bulk density of 50kg/m3, so it is one the lightest products of its kind.”