ANALYSIS ON DISTRIBUTION OF METHANE GAS IN COAL RETREATING LONGWALL MINING METHOD USING LABORATORY SCALE MODEL

• Main Author: Fauzan Edher, Halim
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/54611
• Institution: Institut Teknologi Bandung

Underground mining are well-known for the huge risks that they possess. One of the biggest risk in this mining activity is mine explosion that usually happen because of methane emission that exceeds the limit allowed. In order to keep methane concentration under the bar, we have to know the behaviour of the gas’ distribution along the mining panel and which area has the highest concentration of methane. The study was conducted using 99.9% pure methane gas that was injected to retreating longwall mining panel model (1:30 scale of real condition). The tests was done to find out the behaviour of methane gas distribution in retreating longwall mining panel. In addition, this study also obtained the value of the diffusion coefficient that indicates the level of methane distribution in the unit of square meter per second using the Taylor eq. (1954). The diffusion coefficient calculation was done through analytical and graphical method using experimental data. The analysis of concentration data showed that the highest methane concentration was detected in the goaf area that tend to trap the gas. In the mining front, methane could be well-dispersed because it was located in the area which air could flow freely. In the 90o elbow was found a great air turbulence that caused the methane could not be dispersed properly. Methane concentration accumulation in the area observed was found directly proportional with methane injection flowrate and inversely proportional with airflow velocity in the mining front. As for in Reynolds Number between 9995.64 and 18325.34 was found a correlation of Reynolds Number and methane diffusion coefficient with an equation of: Re=0.3141.exp(7.10-5.E)