Geochemical Characterization of Rocks to Analyse the Source  of the Acid Mine Drainage Generation

Edy Jamal Tuheteru1*, Anindhita Savira Putri1, Raja Muhammad Firmansyah2, Suliestyah1,  Pantjanita Novi Harami1, Ririn Yulianti1

Geochemical Characterization of Rocks to Analyse the Source of the Acid Mine Drainage Generation
Edy Jamal Tuheteru1*, Anindhita Savira Putri1, Raja Muhammad Firmansyah2, Suliestyah1, Pantjanita Novi Harami1, Ririn Yulianti1

1Program Studi Teknik Pertambangan, FTKE, Universitas Trisakti
2 PT. Batubara Lahat, Sumatera Selatan

Abstract

Mining activities will have an impact on the environment, one of which is the generation of acid mine drainage, which has a very negative impact on the environment around the mining area. PT Batubara Lahat, located in South Sumatra Province, is a company that carries out coal mining using the open pit method. Based on the result of the direct measurements in the field, it shows that the water generated is acidic (pH < 5). Acid mine water is produced due to the oxidation of sulphide minerals and the presence of water as a leachate. Policies or regulations set by the ministry of environment and forestry, where the water quality that will be released into water bodies has a pH value in the range of 6 - 9. According to the results obtained in the field, where the pH value of the water is acidic, it is necessary to carry out geochemical characterization to find out the rocks that generate acid mine drainage. The geochemical characterization of rocks is carried out using several laboratory tests, namely, static and kinetic tests. Static tests is carried out by measuring the total sulfur, paste pH, NAG pH, and the acid base accounting (ABA) method, while kinetic tests using the Free Drying Column Leaching Test (FDCLT). The samples used in this research was taken from pit wall of PT Batubara Lahat with a total of 7 samples (the code is represented by A1, A2, B, C, D, E and F). According to the results of the static and kinetic tests results, it was found that samples A1, A2 were characterized as potentially acid forming (PAF) while the samples B, C, D, E and F were categorized as non-acid forming (NAF). Samples A1 and A2 were located at the top and bottom of the coal seam, thus indicating the influence of coal on the pit wall. The results of geochemistry characterization of these rocks become an important consideration in managing the acid mine drainage.

Keywords: Acid Mine Drainage, characterization, Static and Kinetic Test

Topic: Healthy, Safety, Environmental (HSE), and Hazard Mitigation