Bacterial Metallurgy
Bacterial metallurgy is a type of metal extraction process that utilises bacteria to break down metallic compounds and isolate the metal from its ore. This process reduces the use of toxic chemicals, minimises energy, and has the potential to make more efficient use of ore and recycled metal, thus being cleaner and less harmful to the environment. It can be used for both base metals, such as copper and zinc, and precious metals, such as gold and silver.
Bacterial metallurgy can be used for both oxide and sulfide ores, and involves the use of certain types of bacteria that are known as bioleaching agents. These agents degrade the sulfide bonds of metal compounds and then release the metal in a soluble form that can be recovered through a process called bio-precipitation, where the metal is precipitated out of solution. The bacteria also produce acid, which can help in the extraction process as well.
In oxide ores, the bacteria will oxidise the ore, breaking it down into smaller pieces. They then release sulfuric acid and other compounds that further break down the ore and help to isolate the metal from its ore. The metal can then be recovered from the resulting slurry through various processes, such as filtration or precipitation. This type of metallurgical process is especially useful for processing low grade ores, as it does not require high temperatures or energy input to be effective.
In sulfide ores, the bacteria are able to use their natural enzymatic action to break down the sulfide bonds of the ore’s compounds, allowing for the metal to be released into a soluble form. This helps to separate the metal from its ore without the use of toxic chemicals or high-temperature processes.
In addition to extracting metal from its ore, bacterial metallurgy can also be used to recover metal from industrial scrap and waste. This is a valuable resource and can reduce the need for extraction from natural ores, thus helping to reduce the environmental impact of metal extraction processes.
Overall, bacterial metallurgy is a much greener and more efficient way of extracting metal from its ore than traditional methods. It is also a much better way of safely and responsibly recycling metals from industrial scrap and waste. It has the potential to improve the efficiency of metal extraction and recycling processes and reduce their environmental impact.
