Mexico’s bismuth mining set for nanotech overhaul

[MEXICO CITY] Mexico’s profits from mining bismuth metal could increase tenfold with the use of nanotechnology, if an international research project lives up to its promise.

The BisNano collaboration between Colombia, the European Union and Mexico seeks to produce new, high-value bismuth-based materials for use in fields such as electronics, by exploring the properties of the metal at the nanoscale.

Bismuth is already used in electronic devices, medical products and cosmetics. Produced in large quantities in Mexico and other Latin American countries, it is expensive to extract from its ore, so mining companies often sell it raw.

"Although Mexico produces more than 20 per cent of the world’s bismuth, it is sold with no treatment." Jesús González, director of the Advanced Materials Research Centre in Mexico, tells SciDev.Net. "The project intends to find out if there are ways to use nanotechnology to give this element specific properties that increase its value in the market."

Sandra Rodil, the scientific manager of the project in Mexico, says the main aim is to better understand the properties of bismuth at the nano-level, but that the project also aims to promote technological development and eventually "have a company producing high-technology products based on bismuth nanostructures".

The BisNano website describes the economic benefits of bismuth as "low" but González estimates that a breakthrough with nanotechnology could mean its contribution to the national mining industry reaches two-thirds that of silver — and being sold at ten times its current price.

Rodil, who is also a researcher at the National Autonomous University of Mexico’s Institute of Materials Research, says she expects to see products based on bismuth produced in Mexico in the near future.

Researchers have already characterised and synthesised bismuth-based nanoceramics and nanofilms which could go on to be used in products as diverse as computer drives and solar cells.

The project involves 16 research centres and two small Mexican firms. Mexican and European public institutions have invested about US$3.7 million each in the project so far.

Another aspect of the project is evaluating bismuth as a ‘green metal’ — a substitute for lead and mercury in products. This will involve assessing its environmental impact at all stages from mining to disposal, and toxicity testing.

"Ideally, bismuth could substitute lead or mercury in some of their applications. That is, the advantages are not only economic but go hand in hand with sustainability," says Rodil.