OPTIMIZATION OF LATERITIC BAUXITE RESOURCE MODELING IN TOHO REGION, MEMPAWAH REGENCY, WEST KALIMANTAN

• Main Author: Hindarto, Arif
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/73821
• Institution: Institut Teknologi Bandung

<p align="justify">The regional geology of the research area includes in parts of the Singkawang Batolit with Mensibau Granodiorite and Raya Volcanic rocks from the lower cretaceous age as potential carriers of bauxite deposits. PT Antam Tbk began investigating laterite bauxite deposits in Mempawah Regency and its surroundings in 2006. The bauxite of the research area in Antam's concession will be dedicated grades as % weight of Al2O3 2 < 19.02%, and Corrected R-SiO2 3.20%. Optimization of resource modeling was carried out in this study to obtain optimal resources in quantity, to meet factory feed demands in quality matter, and represent the actual characteristics of the deposit so that it is more effective as input for mine planning and operations. Optimization of the bauxite resource modeling involves dividing the laterite bauxite layer in the study area into two lateral domains and two sub-domains vertically, using top flattening techniques in the grade estimation stage, and applying visual and statistical validation to ensure the optimization results are more representative of the actual conditions of the laterite bauxite deposit as input for estimating bauxite reserves and mine planning. Optimization of this model resulted in an estimate of bauxite resources which increased by 19.25% in washed bauxite tonnage compared to the pre-optimization model, which only used one bauxite domain and without using top flattening techniques, from 25.46 million tons to 30.36 million tons of washed bauxite. The bauxite quality of the optimized model also improved compared to the initial model with an increase in the Al2O3 product content by 2.3% from 41.47% to 42.30%. Impurity grade also relatively decreased in the form of total silica / TSiO2 decreased by 0.3% and reactive silica (RSiO2) decreased by 1.4% from the initial model. Visual validation shows that the results of the optimization model are able to better represent the grade distribution according to the characteristics of the laterite bauxite hilly profile. Statistical validation by comparison of statistical summaries, swath plots, and grade tonnage curves shows that the optimization model produces small deviations from the sample grades and can accommodate simulations of changes in cut-off parameters when there is a change in the economic constraint conditions for bauxite resources.