Measurement and control of external dilution in open-pit mines (Case study: Sungun copper mine)

The phenomenon of dilution is one of the undesirable consequences of mining that is caused by the unwanted mixing of tailings and minerals. Adverse effects of dilution include increased costs of extraction, transportation, processing, mining grade, and environmental degradation. Dilution control requires identifying the causes of the dilution. Field surveys of the East Azerbaijan Sungun copper mine, which is extracted by the open-pit method, show that factors such as dyke infiltration, contact of tailings blocks and mineral at the borders, sample error Vector and Murphy's errors (human error) are the factors influencing the dilution. In this study, in order to estimate the amount of external dilution (dilution due to dykes) of Sungun copper mine, geostatistical modeling (index kriging) was used. The external dilution rate of the mine (11.3%) was calculated. The amount of external dilution seemed to be higher than the maximum initial estimate of dilution in open-pit mines with mass reserves, but this number is reasonable given the presence of dykes. To reduce the external dilution due to the penetration of the dykes, it was suggested to use the XRF model 7000. Statistical data available before and during the use of the XRF device showed that when using the device, the daily average (actual) grade obtained is closer to the predicted grade. Also, the amount of external dilution due to dykes has decreased.