The shells of molluscs can be used to manufacture a heat insulating material. (Photo: otri.us.es)
Mollusc shells used as fire insulation
Tuesday, February 15, 2011, 16:30 (GMT + 9)
An Andalusian research group has patented a material made of mollusc shells which is highly resistant to fire.
The research team from the Waste Engineering of the Department of Chemical and Environmental Engineering, from the University of Sevilla (US), which had the cooperation of the Process Engineering Group of Seville.
This initiative, which was encouraged by the Ministry of Economy, Innovation and Science of Andalusia, has applications in the field of construction and passive fire protection in walls or ceilings, among other places.
Researchers have been working on this project since 2003, when they were contacted by "Galician canning companies that had a problem getting rid of thousands of tonnes of shells," said Carlos Leiva, a member of the research team working group.
The shells are composed primarily of calcium and magnesium carbonates.
By using calcination, they can remove the organic matter and odors that can be generated. Subsequently, the shells are ground and sieved to obtain a granulate that allows it to be mixed with different binders, like gypsum and fiber.
"This product is made in the simplest and cheapest way possible, so that the difference is only the cost of raw materials. The manufacturing process is the same as commonly used products: with components of concrete mixed in water, poured and is then left to set," said Leiva.
The new fire insulation is already approved and has successfully passed environmental and mechanical strength tests in official laboratories.
The invention guarantees "its possible industrialization and competitiveness in the market compared to other commonly used commercial products," added the scientist.
For his part, Luis Vilches, another of the researchers, said that "in other European countries, these and other types of industrial waste are considered by management as a byproduct, encouraging its recycling." But in his view, materials with physical and chemical properties similar to those with conventional materials in construction "should no longer be classified as waste because they have negative connotations when used," informed Andalucía Innova.
By Analia Murias