THE EFFECT OF RAINFALL ON THE GROSS CALORIFIC VALUE OF COAL (CASE STUDY AT PT KALIMANTAN PRIMA PERSADA, RANT SITE)

Abstract

Coal is an energy source whose quality can be influenced by environmental factors, particularly rainfall. This study aims to analyze the correlation between rainfall intensity and total moisture content, as well as its impact on the Gross Calorific Value (GCV) of coal at PT Kalimantan Prima Persada. The data used in this study includes daily rainfall data (mm), and test results of inherent moisture (%) and GCV (kcal/kg), collected over a two-month period from November to December 2024. A total of 30 coal samples were analyzed to determine the relationship between rainfall and total moisture content, as well as its effect on GCV. The collected data were analyzed using regression methods. The results indicate that increased rainfall is directly proportional to the increase in coal's total moisture content, with an R² value of 0.8205, indicating that approximately 82.05% of the variability in total moisture can be explained by rainfall. Additionally, the study discusses the impact of total moisture on GCV. The comparison results show that total moisture has a more significant effect, with an R² value of 0.827, indicating that 82.7% of the variation in calorific value can be attributed to total moisture. These findings are expected to assist the mining industry in implementing better coal protection and storage strategies to maintain coal quality.