Revalorization of Haveri Au-Cu mine tailings (SW Finland) for potential reprocessing

The aim of this work was to make an estimate of the remaining metal resources of the Haveri tailings (SW Finland) that were deposited for 60 years ago. We used existing databases (Cu, Zn, Ni, Co, As, Pb, Ag, Au, Fe, S) of previous valorization performed in the 1980's with high sample density; a total of 1201 tailings samples from 165 drill cores. Cobalt, Cu, and Au were chosen for further statistical evaluation, 3D block modelling, and feasibility analysis. We performed also a volume estimate of the tailings based on the depth of drill cores, which was used for the calculation of the total resources. The grade and total tonnage of remaining Au resources present economic potential in comparison to current Au production, whereas the remaining resources for Co and Cu are less promising for reprocessing. However, further feasibility studies are required. This work may serve as an example to make use of existing databases by means of geostatistical modelling techniques in combination with more profound understanding of the mineralogical associations of the metals.