Nanomaterials have already made their way into various industries and the added value that they bring is starting to be realised by both consumers and industry. One industry where nanotechnology has yet to make much of an impact is the mining industry. However, it has the potential to, and there are many areas starting to be developed where nanotechnology and the mining industry can cohesively work together. As it stands, most of the areas of nanotechnology that could impact the mining industry are currently confined to the academic laboratory.
One potential area is the use of nanosized vessels to recover valuable minerals that end up in the waste. The capability is there with modern day analytical equipment to detect when valuable materials are in a waste stream and can be recycled. It is thought that this recovery process could take on a form similar to drug delivery approaches where nanosized carriers could uptake the species of interest from the waste.
There has also been a method that has been trialled in academia to isolate gold from crude sources. The method could be important if it gains commercial traction as it would enable gold to be extracted without the need for using toxic chemicals (which is the standard process at the moment). The method trialled uses needles composed of nanosized supramolecular wires and can isolate gold from practically any medium. This has laid the foundations for something that could be synthesised commercially, as the synthesis process is relatively quick.
I’ve also heard on the grapevine that there could be some applications for nanomaterials in borehole drilling. As far as I’m aware there have been no reports of this yet, but it something has been discussed by people in the industry. The main area that has been discussed is using graphene coatings on the drill bits that perform the borehole drilling. Because these drilling processes can take some time, especially if it is a deep bore, the drill bits are subjected to a lot of mechanical abrasion, heat, and in some cases, an increased pressure. There is a reason why graphene is being touted for many barrier coating applications, and that is because it is very stable against impact, temperature and reactive chemical species. So, graphene coatings could provide a multifunctional way of protecting these drill bits. Because graphene coatings only usually need a few wt% to be effective, the increase in longevity could also far outweigh the cost of the graphene compared to having to replace the huge drill bits more frequently.
Another area is lubricant additives. While this is not just relevant to the mining sector, heavy-duty machinery is often used which requires effective and regular lubrication for all the mechanical parts to work optimally. If they don’t, then the subsequent wear and degradation of these parts can become costly. In recent years, there have been developments towards using various nanoparticles to improve the lubricating properties of a lubricant. The inherent size of nanoparticles is why they are being trialled. Not only can they fit through the filter systems with ease, they can also penetrate small gaps between mechanical parts, where larger particles cannot. This means that the lubrication properties can be enhanced by the nanoparticles acting as ‘rollers’ when the mechanical parts pass over them. It should be noted that this area is currently confined to the academic laboratory, and because additives require a lot of testing before they are used and integrated commercially, it could be a while before this comes to fruition. But the potential is there.
Written by Liam Crtichley.