In South Africa, more precisely in Witwatersrand Basinthere could be a hidden “treasure of invisible gold“, whose value could even reach i 24 billion dollars.
Already in the 19th century, this region was at the center of a gold rush which proved so profitable that it gave rise to the city of Johannesburg. If we wanted to estimate all the gold that has been extracted from here we could say that it is approximately 40% of all the world’s gold. However, these extractions left enormous hills of mining waste that are called tailings.
The 26-year-old metallurgist originally from Zimbabwe, Steve Chingwaru, recently conducted research that turned out to be extraordinary. In fact, in 6 billion tons of tailingspresent around the Johannesburg mines, could be contained up to 460 tons of “invisible gold”.
Why is it called “invisible gold”?
This type of gold is not visible to the naked eye as it does not come in the form of nuggets, but it is trapped in small quantities inside of of other minerals. This is why it gets the nickname invisible.
New method to reprocess mining waste?
Chingwaru, with his doctoral project, quantified the gold present in the tailings and searched a more efficient method
of current ones to reprocess this waste. Chingwaru further explained the current importance of low concentration gold sourcesgiven the depletion of highly concentrated reserves.
The current methods of exploiting tailings, as well as being ineffectivethey also turn out harmful to the environment. In fact, when sulfides oxidize, they produce sulfuric acid which can contaminate aquifers. This problem appears to be very serious in some areas of Johannesburg.
Chingwaru said he was excited to highlight economic potential hey environmental benefits of the efficient reprocessing of tailings. His method promises not only to extract gold, but also to reduce or eliminate pollution from heavy metals and water acidification.
According to this study, Johannesburg tailings contain gold worth R450 billionapproximately 24 billion dollars.
But is this new method economical enough to make this operation profitable? Chingwaru naturally asked himself this question and spoke to several experts in the South African mining industry. These experts believe that the method to become economically sustainable can be climbed, especially if the price of gold remains high. For everyone, gold mining would be expensive, but you could still get a nice profit.
