What Is BioMetallurgy
BioMetallurgy refers to the biotechnological procedures that deal with relations between living organisms and metal compounds (including minerals). As the day goes by, there is a continuous need for the growth of green low-carbon energy technologies, which requires certain metals, majorly PGMs (platinum group metals) and REEs (Rare earth elements).
Also, we are challenged by geopolitical limitations during our search for these metals, which has attracted concerted efforts of the government and various industries. Therefore, it is pertinent to devise a sustainable plan to obtain these metals from their primary state (ores) or secondary streams, and the most effective means has been one provided by biotechnology.
That is the recovery of these metals through microorganisms. In essence, biotechnology through BioMetallurgy offers solutions to the challenges faced during metal mining and production. Some metals are deemed critical because of their role and the influence they have in secondary and urban mining and are often recovered from waste streams using microorganisms.
BioMetallurgy increases the chances of obtaining metals from mineral resources (low-graded) through bioleaching processes. It is a biotechnology firm that operates around concepts such as biomining, bioleaching, bioaccumulation and biosorption.
Bioleaching refers to the disintegration of metal compounds from their sources by microorganisms. The process may naturally occur or use microorganisms to produce organic acids or other solubilising elements. Hence, this procedure may be the direct or indirect metabolism of microorganism.
The process of BioMetallurgy is eco-friendly, not toxic, consumes low energy and can allow intense concentration treatment. The scope of BioMetallurgy includes oil recovery, microbial mining, bioleaching, waste management, waste management and metal recycling.
BioMetallurgy is a cheap procedure compared to the conventional mining process. It is sometimes utilised when the traditional method is ineffective in extracting certain metal compounds such as gold, copper and Zinc.
Selection of Critical Metals
Natural resources in which the risk of supply scarcity will influence the economy extensively are called critical metals. The demand for this material is high because of emerging low-carbon technologies, but the means of satisfying them is limited. According to the EU (European Union), there are twenty critical raw materials: PGMs, Bulk metals, REEs, industrial minerals, etc.
REEs (rare Earth element) include dysprosium, terbium, europium, neodymium and yttrium. Most researchers focused on REEs and PGMs because of their relevance to futuristic research.
How It Works
For primary ores such as Copper, Nickel, Gold etc., the extraction process is known as heap bioleaching. Sometimes, miners may utilise bio-oxidation depending on the nature of the mineral and location.
REEs are usually mined in the form of either carbonates or phosphates for igneous and alkaline rocks. It may also be absorbed in the form of clay minerals.
Biomining to Biorecovery
BioMetallurgy requires step by step process. Hence, it takes longer than the traditional method. It involves several techniques, such as biomining and biorecovery. Biomining is the process of extracting metal from ore through the metabolism of microorganisms. The process uses microbes to oxidise the metals and allow them to dissolve in liquid (recovery).
For Bio recovery, three major waste streams offer opportunities to recover critical metals, and they are pre-consumer manufacturing remnants, recycling and urban mining. Researchers and academics target the former two because of the high concentration of REEs and PGMs.