Establishing Research Indicators of Quantity and Assessment Economic Values of Na Tum Pb-Zn mine in Bac Can Province, Vietnam

3. Geophysical Division, Vietnam

Abstract: At present, there are many mines in Viet Nam that have been explored and exploited; however, useful accessory elements have not been explained regarding cutoff grade as well as value of mines in order to determine the charge for granting the mineral mining rights. This problem is not only reducing the mine's economic value and causing loss of mineral resources but also significantly draining the charge for granting the mineral mining rights, in addition to the unequality for mining investors. The results show that: Pb-Zn ore of Na Tum deposit, the cutoff grade should be used flexibly and depends on the type of natural ore as well as the ability of the useful accessory element recovery to select the official and suitable cutoff grade for each ore and ore bed. Beside that, If only the main elements (Pb-Zn) are calculated, the average content of ore beds in Na Tum deposit is lower than the cutoff grade; if the useful accessory elements (Fe, Mn, Ag) are calculated, the average content converted into (Pb - Zn) for the IVa ore bed is 1.55 times higher and the ore bed IVb is 1.8 times higher than the cutoff grade, the remaining ore beds are unsatisfactory for the cutoff grade at the time of assessment. The recoverable potential value (GTNth) and URV for the main elements (Pb + Zn) are much lower than the recovery of useful accessory elements (Fe, Mn, Ag); At the same time, the calculated value also indicates that the recoverable potential value and URV depend not only on the recoverable value of the main elements and the useful accessory elements, but also on the concentration and reliability of recoverable reserves/resources.