Çoraklıtepe (Dutluca, Balıkesir) Altın Yatağının Arama Sondajları ve Tenör Kontrol Çalışması Örnekleri Kullanılarak Kaynak Kestirimlerinin Değerlendirilmesi
Özet
The objective of this thesis is to create and compare mine resource models using core drilling data and grade control data from the Çoraklıktepe Gold Mine in Balıkesir, whose production activities and rehabilitation process have been completed, and to examine the differences that arise. This will help demonstrate the impact of data sets, sample frequency, and sample homogenization on mineral resource model outcomes. In this context, geostatistical evaluations of both data sets were conducted. Solid models were made considering the lithological properties and grade contents of the samples. Compositing and top cut value determination applications were performed. Kriging Neighborhood Analysis was conducted to determine the number of discritisation points and block sizes. Block models were created using the determined block sizes. Variogram fan maps were produced to determine the directional relationship between samples. Experimental and model variograms were created in the identified directions, the nugget effect, total sill value, and the three-dimensional lengths of the search ellipsoid were determined. Mineral resource estimations were made for both data sets using the Nearest Neighbor, Inverse Power of Distance, and Ordinary Kriging methods. Sections obtained from the created mineral resource models using representative intervals were compared with the sample data in terms of both geometry and gold contents. Swath Plot Analysis was conducted to compare the model grade averages and sample grade averages in three dimensions using sections taken at 30-50m intervals in the X, Y, Z directions. The reasons for discrepancies were identified at points where comparisons were not consistent. Additionally, model and sample grades were compared and validated according to domains. To compare the tonnages and total gold contents of the models, the common area between the topographical surface before production activities began and the topographical surface after mining activities ended was evaluated. The results showed that the model created with grade control samples was 29% higher in tonnage, 7% lower in grade, and 24% higher in ounces compared to the model created with exploration drilling samples. The main reasons for these significant differences between the models were found to be the low frequency and uneven distribution of the exploration drillholes. This thesis demonstrates the importance of the preliminary geological study that needs to be conducted during the feasibility stage before mining activities commence and the potential outcomes if the preliminary geological study is not properly conducted or if the obtained insights are not effectively used during the drilling planning stage.
