STUDY OF OPEN PIT MINING OPTIMIZATION AT GOLD ORE MINING PT XYZ

• Main Author: Laksmi Utaminingsih, Citra
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43999
• Institution: Institut Teknologi Bandung

PT XYZ is one of the gold mining companies which has operated in Indonesia. Based on the results of continued exploration conducted by PT XYZ, it is known that there is a gold vein resource that has the potential to be mined by the open pit method. PT XYZ has designed a pit design for these resources and the results of evaluations carried out indicate that the design is economical or mining-feasibly. However, PT XYZ wants to know whether the pit design that has been made is optimal in terms of economy and reserves. In addition, PT XYZ also wants to know the effect of the gold selling price fluctuations and operating costs on the amount of reserves. Ultimate pit limit determination is carried out by using Whittle software which applies the Lerchs-Grossmann Algorithm pit optimization method. From the results of the pit optimization, the values of overburden volume, ore tonnage, Au levels and the optimal pit limits to be mined are obtained. Furthermore, a new pit design is made based on the results of the pit optimization that has been obtained and calculated the value of the profits to compare with the PT XYZ pit design. Analysis of fluctuations effect in the gold selling price and operating costs on the amount of reserves is carried out using the same method and software by changing the input parameters of the gold selling price and operating costs. From the optimized pit design, with a gold selling price of US$1,506/troy ounce, the optimal reserve to be mined is 22,649 tons from the total 304,036 tons of available resources. The optimized pit obtained a profit of US$3,845,839. This result is greater than the PT XYZ pit design which only provides a profit of US$170,682. The simulation results of the effect of fluctuations in the gold selling price and operating costs on the amount of reserves show that fluctuations the gold selling price are directly proportional to the amount of reserves, while operating cost fluctuations are inversely proportional to the amount of reserves.