The Microbial Mystery
One of the significant advantages of traditional mining techniques over biomining is time. Biomining takes a longer time to finish the metal discovery process, although safer for environmental protection. Whether months or years, the period will depend on the type of operation. A dump procedure to recover copper may take up to six years, while a heap process takes a shorter time (six months to a year). On the other hand, a tank operation requires three to five days.
The microbial mystery concerns thoughts on what takes place in the heap, tank or dump. That is, how microorganisms react when breaking down chemical complexes. Also, there has not been any explanation for different approaches utilised by various microbes. While some microorganisms perform oxidation on the cell surface, others prefer it on the inside.
Often, different microorganism species may be mixed for biomining, especially using the heap procedure; but, no scientist can answer which of the organisms does not take part in the process. It is noteworthy that diversity in such a heap is usually caused by exposure to the environment and factors such as temperature and acidity.
These mysteries remain unknown, and many researchers have admitted to this truth. For instance, Barrie Johnson, a professor in environmental biotechnology at Bangor University, UK, stated that the problem of biomining is time. In another example, Coral Brierley, a biomining expert in the US, admitted researchers and experts are ignorant of what goes on in a heap.
However, these mysteries are limited to biomining. Biooxidation is a level of control exerted on bioreactors which usually comprises only four to five microbial species. Often, it also contains a combination of iron and sulphur oxidisers and organic consumers. Nonetheless, there seems to be no explanation for the alteration that happens to bioreactors during operation.
In all of these mysteries, one particular fact and truth is that biomining is the only sustainable technique for obtaining metals from low-valued minerals without detrimental effects on the environment. It is also known that these minerals, especially REEs (rare elements), would become a significant element industry that we cannot do without in the future.
There is no way biotechnology can be avoided. As confirmed by Johnson, ores with high value are increasingly growing scarce without a decline in the demand for the metal. Hence, people must devise a sustainable method of extracting low-value minerals.
The most affected element is probably copper. The low-valued minerals are now the biggest supplier of copper, especially those that contain Chalcopyrite. It is the largest copper supplier, accounting for at least 80% of the total supply globally.
However, one problem with this element is that it is neither receptive towards traditional extraction procedures, nor is it submissive to biomining either. The only reasonable explanation for this is that the component is covered in a protective layer that prevents full oxidation. Only about thirty per cent of the ore appears leached. Nonetheless, biomining at a very high temperature seems more effective than the traditional method, although no explanation is offered for this.