Tailings are the materials left after the process of separating the valuable fraction from the gangue of an ore. During ancient world wars, countries needed some special minerals and they exploited only the minerals they needed. Other unused but valuable minerals were stored in the tailings.
The other important factor is related to accuracy of methods for mineral processings and correct design of plants established for mineral exraction and processing.
It is well known that over 1.000.000 people work at the small scale and artisanal mines especially in the Commenwealt of Independent States (CIS), South America, Africa.
There are recoverable gold content varying between %40 and %60 within million tones of wastes of these mines. EarthandSpace Company conducts projects to recover gold within the tailings over 80 % yield.