Periodic Reporting for period 2 - BiotaMet (A novel biotreatment technology for sustainable metal extraction from low-grade ores, tailings and WEEE)
Période du rapport: 2021-10-01 au 2023-09-30
The increasing complexity of industrial and consumer products, especially the transition to carbon-neutral energy production has created a rapidly rising demand for various metals. The need for some of them like lithium, cobalt and rare earth elements are projected to rise at least in order of a magnitude in coming decades. At the same time, metal-rich ores bodies are increasingly becoming exhausted, causing shift towards low-content sources. However, most established methods of metal extraction such as pyrometallurgy and hydrometallurgy are polluting and with high energy demand. These factors, together with increasing energy and CO2 prices have created a perfect storm where demand for metals are increasing but the supply has become economically unfeasible in EU. This has lead to a situation where some non-democratic countries with less stringent environmental regulations and histroy of using trade leverages for geopolitical gains are controlling the import of most of the Critical Raw Materials (CRMs) supply to the EU. Recognizing this potential hazard to its industry, EU has made achieveing strategic autonomy a political priority. The solution exists in the form of numerous low-grade ores and technical waste stream, accumulated in various EU countries over decades of mining/extraction activity. While considered low-grade, the overall amount of REE-s and other metals is sufficient to satisfy EU-s demand for decades to come. These sources are, however, economically unprofitable to be exploited with legacy methods, so there is a high demand for a method that can extract metals efficiently, being at the same time environmentally friendly.
Bioleaching, a method of metal separation utilizing microorganisms fits the bill by being non-polluting and having a low energy demand. While efficient in lab-scale, the issues with leaching speed, material specificity, cost-efficiency and upscaling have hampered its widespread industrial use. We aimed to address these issues by developing BiotaTec’s robust bioleaching method termed BiotaMet into industrially applicable solution.
Bioleaching, a method of metal separation utilizing microorganisms fits the bill by being non-polluting and having a low energy demand. While efficient in lab-scale, the issues with leaching speed, material specificity, cost-efficiency and upscaling have hampered its widespread industrial use. We aimed to address these issues by developing BiotaTec’s robust bioleaching method termed BiotaMet into industrially applicable solution.
Our goal was to modify and upscale BiotaMet technology to a robust and versatile technology that can be used for different ores and industrial wastes. For this developmental procedures with several low-grade metal sources, including phosphogypsum, bauxite residue, graptolitic argillite etc. were carried out. At first, this included the design and construction of industrial pilot-scale reactors, specifically planned for testing and development of BiotaMet’s technology. This was achieved with construction of series 1000L reactors at our pilot plant unit which gave BiotaTec a capability for rapid upscaling of bioleaching solutions, unparalleled in Estonia or Baltics/Finland.
The optimisation process of BiotaMet started at lab-scale with sequential step-by-step upscaling via 20L, 100L and 1000L state-of-the-art bioleaching reactors. For the economically most interesting metals in materials named above, leaching efficiency was improved to and above 80-90% with significant decrease in leaching time. Generation of methane from organic component in argillite was similarly upscaled to 1000L with simultaneous increase in efficiency of gas generation above what was ever achieved in a laboratory scale. The last aspects of metal leaching upscaling are currently undergoing additional modifications in 1the 000L reactor to increase resilience against possible contamination issues in industrial settings.
The optimisation process of BiotaMet started at lab-scale with sequential step-by-step upscaling via 20L, 100L and 1000L state-of-the-art bioleaching reactors. For the economically most interesting metals in materials named above, leaching efficiency was improved to and above 80-90% with significant decrease in leaching time. Generation of methane from organic component in argillite was similarly upscaled to 1000L with simultaneous increase in efficiency of gas generation above what was ever achieved in a laboratory scale. The last aspects of metal leaching upscaling are currently undergoing additional modifications in 1the 000L reactor to increase resilience against possible contamination issues in industrial settings.
This project has allowed us to reach the point where our technology is attracting customers around the globe, both from mining and metal processing industries. In addiiton of hugely increasing the strategic autonomy of EU’s industry, there are several additional benefits associated with processing of waste streams. Over decades, mining wastes such as phosphogypsum and bauxite residue have accumulated in various parts of EU, totalling in billions of tons. For example, easily accesible phopshogypsum reserves alone are estimated to be in amount of 2 billion tons. Since these waste materials also contain radionuclides and toxic heavy metals, they are not disposed of but deposited in huge stacks. BiotaMet technology does not only take out CRMs but also removes contaminationg these substances. As a result, “cleaned” substance can be re-inserted into circular economy and utilised e.g. as a construction material.