Researchers to combine viruses and amino acids to develop eco-friendly mining processes

Québec City, November 13, 2019–Researchers from Université Laval and the COREM centre of expertise and innovation have set out to combine bacterial viruses and amino acids to develop a more eco-friendly alternative to the chemicals used by the mining industry to process ore. The research project announced today will last three years and will receive$1 million in funding from public and private partners.

Mining companies generally use a process called «flotation» to separate ore from unwanted materials collected during mineral extraction. «The first step is to grind extracted rock into very fine particles,» explains Professor Alain Garnier, a chemical engineer in the Faculty of Science and Engineering and leader of the project. «We then suspend those particles in an aqueous suspension and add chemicals that make the mineral we're interested in water repellent. Next, we aerate and agitate the mixture. The mineral moves away from the water and takes refuge inside air bubbles, which rise to the surface. Then we simply collect the foam that contains the ore we're after.»

The problem is that some of the chemicals used can impact the environment. Professor Garnier and his collaborators came up with the idea of replacing those chemicals with peptides, naturally occurring short chains of amino acids that are the basic components of life. «These amino acids are like blocks that can be arranged in an almost infinite number of patterns to obtain substances with a range of properties,» he explained. «By combining the twenty or so amino acids that occur naturally, we can obtain billions of peptides with different properties.»

Preliminary work has shown that certain peptides have affinities with different metallic particles. The goal of Professor Garnier and his colleagues will be to find, among these billions of possibilities, peptides that can attach to the targeted metals and that are sufficiently water repellent to bring these particles up to the surface.

To sift through the vast quantities of peptides, the researchers will use a technique known as «phage display.» The technique uses bacteriophages—«phages» for short—which are viruses that specifically attack bacteria. «These phages, which are totally harmless to humans and the environment, are used as a substrate on which peptides are exposed to make it easier to observe their properties,» explains Professor Garnier. «By combining this technology with deep sequencing and artificial intelligence, we can randomly create and select hundreds of millions of peptides very quickly.»

After identifying peptides with potential, the researchers will use molecular modelling to optimize their useful properties. Then bioengineers will get involved to develop processes for producing the peptides in large quantities at a competitive cost. The metals targeted are mainly zinc, nickel, copper, gold, and silver.

«Because they are made of short chains of amino acids that are the basic components of life, the peptides we identify will have a much lower impact on the environment than the products currently in use and will also be much easier to break down,» says Professor Garnier.

COREM, a centre of innovation in ore processing based in Québec City, is the driving force behind the project. «A lot of mining companies want to replace their chemical reagents with products that don't impact the environment and are more effective,» explains Caroline Olsen, researcher and manager of COREM's extractive metallurgy program. «We also want to develop an innovative solution that would reduce the environmental impact of certain ore processing methods,» adds Phillipe Gagnon, Director of Innovation and Digital Solutions at COREM. «In order to tackle this major challenge it made sense to combine funding, so we started talking to Université Laval and our partners to launch the project being announced today.»

Financial partners
The financial partners for the project are Consortium de recherche et innovations en bioprocédés industriels du Québec (CRIBIQ), the COREM centre of expertise and innovation in mineral processing, Mitacs, NSERC, chemical manufacturer Chemiqa, and mining company Agnico Eagle Mines.