Classification and reserve estimation of Robat Arregije Pb-Zn deposit, Khomein ‎Township, Markazi Province, using geostatistical methods ‎

Ore reserves can be classified on the basis of various criteria. Geostatistical methods are ‎highly accurate to estimate and classify ore reserves. The most important geostatistical ‎methods to classify the ore reserves are number and quality of the data involved in ‎estimation, error of Kriging variance and Kriging efficiency. In current research, the ore ‎reserve of Robat-Arregijeh lead-zinc located in Khomein township in Markazi province, has ‎been classified into three classes comprising proven, probable and prospected. In order to ‎better recognizing the deposit and ore nature, first the strip log of all boreholes and 3-D ‎lithology model of the region were drawn using Rockworks software. To estimate the ore ‎reserve after variography of the region with SGEMs software, geostatistical ordinary block ‎log-kriging method was used by DATAMINE software. By considering different economic ‎conditions, average grade and amount of the ore reserve were estimated for cut off grade 1.5, ‎‎2 and 3 weight percent. The comparison of the research results shows that amounts of ‎reserves classified by the various methods are highly different. Number and quality of the ‎data involved in estimation method with respect to the two others, yields higher value for ‎proven reserve, with less accurate reversely. Therefore in practice these two methods are ‎preferred in the first method. The amount of probable reserve of each three methods is close ‎to each other.‎