TECHNOLOGY

Fermenting a minerals extraction revolution

What if beyond its obvious uses in beer and kimchi, yeast could help mining become cleaner and more productive?

 Biosurfactants can penetrate much deeper into rock pores

Biosurfactants can penetrate much deeper into rock pores

Surfactants are an essential part of the mining industry, but whether petroleum- or chemical-based, they can in some cases be non-biodegradable and even toxic. Yeast, on the other hand, is totally natural and one of the oldest known organisms on Earth - at over 400 million years old, it's even older than dinosaurs and even flowering plants.

Locus Fermentation Solutions, a Solon, Ohio-based chemical business, is exploring ways to use yeast to make "bio-surfactants" that perform chemical processes in a number of industries - from water management to cosmetics, food processing and mining.

The Locus Mining division is developing yeast-derived biosurfactants to extract minerals and metals from lower-grade ores and waste dumps. The biosurfactants work by lowering the surface tension of water, which allows it to penetrate rocks and ores more easily. This makes it possible to extract minerals and metals from ores that are too low-grade to be mined using traditional methods.

Mining Magazine sat down with Gabi Knesel, SP of Locus Mining to learn more about the process.

Can you give us some background to Locus Mining and on your solutions?

GK: Certainly. Locus Mining is the latest subsidiary of our parent company, Locus Fermentation Solutions, a biotech company. Locus Fermentation Solutions was founded by two entrepreneurs, one a lawyer and the other a scientist, with a track record of establishing successful ventures. One notable example is a company they sold a few years ago called Gannett, which patented a technology for non-refrigerated probiotics. Afterward, they launched Locus. About nine years ago, we began producing biosurfactants, which are essentially green chemicals. They serve the same functions as petroleum-based chemicals but are derived from natural sources like vegetable oils, sugars, and yeast through fermentation. Our challenge was in scaling up production to meet industry demands.

MM: Could you explain what these green chemicals do and their advantages?

GK: We've found that our biosurfactants can make a significant impact in several areas, particularly in the mining industry. They are applied in the two main processes of hydrometallurgy: leaching and flotation. These processes aim to separate valuable minerals from waste. Our biosurfactants, due to their unique chemical characteristics, require only small doses to have a significant effect. Additionally, they have much smaller molecule sizes, allowing them to penetrate rock pores more effectively, leading to higher recoveries in applications like leaching. They also have prolonged activity, remaining effective in extreme conditions, such as high temperatures and pressures. Moreover, they are compatible with acids, are sustainable, and have no live organisms. This aligns with mining companies' efforts to achieve net-zero carbon goals.

MM: Why is your company applying these products to mining and how does it work?

GK: Firstly, it is important to note that biosurfactants differ significantly from traditional chemicals. They are more intricate, with a greater number of chemically active sites in the molecule, which comes with its own set of advantages.

One notable characteristic is that we require only small doses of these ingredients in an application to make a substantial impact. This low dosage requirement is a significant advantage. Additionally, the size of these molecules is much smaller compared to traditional surfactants. You might wonder why this matters.

In leaching, a common process, the typical surfactant size is around 100 nanometers. In contrast, our biosurfactants are about three nanometers, comparable to the size of DNA. This allows our biosurfactants to penetrate much deeper into rock pores. For example, in copper leaching, we mix these biosurfactants with sulfuric acid, while in gold leaching, we combine them with sodium cyanide.

The biosurfactant acts as a carrier for the acid, facilitating its transport into smaller pores, resulting in higher recoveries. These characteristics make our biosurfactants exceptionally well-suited for mining applications. Additionally, they exhibit superior adsorption and sorption properties, as these molecules take much longer to be absorbed in an application.

 This means they have a longer-lasting effect. They remain active even in extreme conditions, such as high pH levels, elevated temperatures, and high pressure. They are also compatible with acids, contain no live organisms, and are environmentally sustainable.

When we present our technology to mining companies, it's crucial to highlight these points. I'm sure you're already well-acquainted with various mining companies and service providers in the industry. Major global companies like BHP and Anglo-American have comprehensive net-zero carbon plans in place, aiming for achievement by 2050.

These plans encompass different areas, including the goal of having carbon-neutral suppliers to eliminate scope three emissions. At Locus, our manufacturing plants are carbon neutral, and our products are both biodegradable and non-toxic. This means that if a mining company needs to release our biosurfactants onto land or into water, it has no adverse environmental impact.

MM: How far along are you in the development stage? Are you ready for trials already? What's the next milestone for you?

GK: Currently, we've already developed our initial products. We're focusing on three specific metals in the short term. The selection of these metals was based on geographical proximity to our plants in the US. As our initial launch is in the US, we're targeting the metals that are pivotal in the country's mining industry: copper, gold, and iron ore, with respective market shares of approximately 33%, 30%, and 10%. These metals are our primary focus, and we're currently testing products for them in our lab.

One example I'd like to highlight is a product utilising our biosurfactants specifically designed for copper leaching. Mining companies can incorporate this product seamlessly into their existing processes without the need for any operational adjustments. This ensures a smooth transition and cost-effectiveness. In terms of copper leaching, our first-generation product is already showing promising results, with recoveries ranging from five to seven percent overall. Notably, a significant portion of these recoveries comes from insoluble copper, a challenging component in leaching processes.

Moving on to gold, we've achieved exciting progress in our lab tests. We recently conducted a trial with a potential customer, and while we're still in the pilot phase, the next step will involve an industrial trial in Peru. The results were impressive, demonstrating a 2.48% increase in recovery rates. While this figure might seem modest, in the context of gold mining, it represents a substantial improvement. Additionally, we've made strides in reducing cyanide usage, with one combination of biosurfactants achieving a 70% reduction. This is particularly significant for environmentally sensitive regions like California and Alaska, where such reductions can pave the way for smoother permitting processes. We're in contact with companies facing these challenges, and we're optimistic about how our technology can assist them.

MM: I noticed the reduction in overall emissions achieved through the products. Can you explain these environmental benefits?

GK: Absolutely, we're deeply committed to delivering environmental gains across three key areas.

First and foremost, we're focused on carbon reduction. By enhancing recovery rates, we inherently decrease the carbon footprint. We're in the process of obtaining certification through SGS, an auditing company based in Switzerland. This certification will be awarded to companies using our products, signifying a reduction in their carbon emissions. This is monumental, as it directly impacts operational logistics. For instance, if a company achieves higher recovery rates, it means fewer trucks are required to transport material within the mine. This translates to a substantial reduction in emissions, especially given the heavy equipment involved.

Next, our products exhibit characteristics beneficial for flotation processes. Traditional chemicals used in flotation have larger molecules, while our biosurfactants possess more complex, smaller molecules. This leads to more effective coating of minerals, resulting in improved recovery rates. Moreover, our biosurfactants facilitate flotation with less material crushing, leading to significant energy savings and reduced carbon emissions.

Finally, we're making strides in water conservation. By incorporating biosurfactants into filtration processes, we're achieving exceptional results. In mining operations, filtration aids are used in both concentrate and tailings processing to save water and enhance safety. Our biosurfactants enable drier tailings, reducing moisture content by up to 10%. This not only translates to substantial water savings but also improves safety and operational efficiency.

These combined efforts in carbon reduction, energy savings, and water conservation are not only environmentally significant but also indicative of the positive change our technology can bring to the mining industry. As the industry shifts towards more sustainable practices, we believe our solutions will play a pivotal role in meeting the demands of a changing market, especially with the increasing need for minerals driven by the rise of electric vehicles and related technologies.

 

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