The ash spewed by volcanoes is reactive enough to be used to make several kinds of cement, according to research by scientists in Spain. The conclusion is based on testing of ash samples taken from last year’s eruption of the Cumbre Vieja volcano on the island of La Palma.



A research team based at the Universitat Politècnica de València (UPV), has found that volcanic ashes are sufficiently reactive to be applied in the manufacture of several types of cement.The samples were taken from the Cumbre Vieja volcano, on the island of La Palma, which erupted in September 2021 for 85 days, after lying dormant for over 50 years.

The ashes produced by each volcano are distinctively different, according to researchers, and the relative youth of the samples from La Palma could make the ashes have characteristics that could be leveraged by the construction sector to support its decarbonisation efforts.

“To date, we have carried out physical, chemical, mineralogical and mechanical tests, and the results show that these volcanic ashes meet the regulatory requirements for use as a mineral addition in cements,” said Jordi Payá, a researcher on the team.

Clearing the ashes created by the eruption is a massive task, as they covered over 5,500 hectares (14,000 acres) of the island.

Instead of discarding them, the research team believed that the waste could be managed by utilising it for the manufacture of construction materials while also creating social impact and supporting the island’s recovery plan.

“These volcanic ashes should be considered as natural waste, as it is a material that has occupied or is occupying spaces that correspond to infrastructures, industries, roads, farmland and housing, hence the importance of carrying out these studies to be able to reuse this material”, said María Victoria Borrachero, another member of the research team.

The worldwide production of cement contributes about 5 per cent of human-generated CO2 emissions every year, according to a 2017 study. Despite its negative impact in the environment, the rate of cement production has not slowed down in recent years.