Abstract. Mining material other than coal forming interburden and parting can cause a decrease in coal quality. Rocks that adsorb air and join are mined with coal, compensating for moisture and sticky compilation of water and increasing the value of total moisture. Entering material other than coal in coal products needs to be assessed to minimize the decline in coal quality.The majority partings are composed of clay minerals (inorganic) which have an ash value of 15.71%, resulting in an increase in ash value of 0.99% in coal products when mined together with coal seams. Ash value becomes high when there is an abundance of inorganic material (minerals). In the SL 23 seam coal product in the port stockpile, there was an increase in ash value of 1.42% of the SL 23 seam coal product in situ due to the dilution factor during mining activities.TM value in coal products increased by 5.56% when coal products were stacked in the stockpile due to rain that occurred on 19-29 June 2018. The kaolinite and illite clay minerals played a role in the process of increasing the TM value of coal products, due to the hydrophilic mineral properties can draw water to the mineral surface when exposed to water which causes the condition of coal products to be wet and runny.Partings that are mined together with coal seams are composed of kaolinite and illite clay minerals which are able to draw water to the mineral surface (Adsorbtion). This causes a condition where coal particles become sticky with water particles that exist on the surface of the clay minerals in the parting material due to the tensile force between the non-similar material (Adhesion). The condition of coal products that are wet and runny due to parting material that attracts water causes sticking properties between the parting material and coal.Keywords: Sticky Coal, PartingAbstrak. Material tertambang selain batubara antara lain berupa material interburden dan parting dimana material parting tersebut dapat menyebabkan penurunan kualitas batubara. Parting bersifat adsorbent terhadap air dan dalam proses penambangan material tersebut ikut tertambang bersama batubara. Sifat adsorbent parting dapat mengakibatkan kondisi basah dan lengket ketika terkena air dan akan terjadi peningkatan nilai total moisture. Bercampurnya material selain batubara pada produk batubara perlu dikaji untuk meminimalisir terjadinya penurunan kualitas batubara. Parting mayoritas tersusun atas mineral lempung (Anorganik) yang memiliki nilai ash 15,71%, mengakibatkan kenaikan nilai ash sebesar 0,99% pada produk batubara ketika ditambang bersama lapisan batubara. Nilai ash menjadi tinggi bila terdapat limpahan material anorganik (Mineral). Pada produk batubara seam SL 23 di stockpile pelabuhan, terjadi kenaikan nilai ash sebesar 1,42% dari produk batubara seam SL 23 kondisi insitu akibat faktor dilusi saat kegiatan penambangan. Nilai TM pada produk batubara mengalami kenaikan sebesar 5,56% saat produk batubara ditumpuk di stockpile akibat hujan yang terjadi pada tanggal 19-29 Juni 2018. Mineral lempung kaolinite dan illite berperan dalam proses kenaikan nilai TM produk batubara, akibat dari sifat hydrophilic mineral yang dapat menarik air ke permukaan mineralnya ketika terpapar air yang menyebabkan kondisi produk batubara menjadi basah dan berair. Parting yang ditambang bersama lapisan batubara tersusun atas mineral lempung kaolinite dan illite yang bersifat dapat menarik air ke permukaan mineralnya (Adsorbtion). Hal tersebut menyebabkan kondisi dimana partikel batubara menjadi lengket dengan partikel air yang ada pada permukaan mineral lempung pada material parting akibat gaya tarik menarik antar material tidak sejenis (Adhesi). Kondisi produk batubara yang basah dan berair akibat material parting yang menarik air menyebabkan timbulnya sifat lengket antara material parting dengan batubara.Kata Kunci: Batubara Lengket, Parting.