Drillhole modelling using geological characteristics and conditional simulation for mining feasibility studies: Case study on an iron ore mine in Sierra Leone

The unpredictable fluctuations in metal price, political instability and socio-economic problems in resource rich areas are among the reasons why the mining industry needs to look for ways of maximizing returns whilst keeping operating costs at their lowest. In this research, the potential of improving exploration programs was investigated using a drillhole data modelling scheme based on the geology of the deposit. Secondly, the application of Geostatistical Simulation for mine design was investigated. A dataset consisting of 539 drillholes was used as a case study with grid dimensions of x (3100 m) by y (3800 m). Using the drillhole modelling scheme, the drillholes were segmented into groups using geological features based on which five (5) possible geological patterns were constructed. Each geological pattern was simulated 1000 times to capture the space of uncertainty, and the simulated realizations for each of the pattern were averaged to produce one block model per pattern. This modelling scheme showed how the geological information can be used optimally to reduce drilling requirement during mining feasibility studies. From analysis, it was concluded that the project could save the drilling and sample analysis cost combined by a margin of 32% using this method.