Durability is defined as a measure of a rock's resistance to weathering and disintegration when the rock undergoes weathering processes over a short period of time. The susceptibility of rocks to disintegration is related to their low durability. Rock durability is often measured using the slake durability test. The slake durability test is widely used to assess physical changes resulting from wetting-drying processes (Franklin and Chandra, 1972). Therefore, slake durability testing is conducted to understand the weathering of rocks caused by heat and water, particularly clay stones which are one of the constituent rocks on a slope. The sampling location is around Sanga-sanga and Muara Badak. Sampling was conducted with coordinate points and the Balikpapan and Kampungbaru formations. The claystone samples taken were then brought to the Mineral and Coal Technology Laboratory of the Engineering Faculty of Mulawarman University for Slake Durability tests. In this study, the lowest index value obtained was 45.7% and the highest value was 93%, indicating high to very high durability. The difference in the durability index values of claystone at the research locations indicates the presence of variables that can affect the slake durability index values of the claystone in the Balikpapan and Kampungbaru formations, including grain size and mineral content as well as geological conditions at the research site. Based on the results of the claystone durability tests, the durability index value (Id2) was obtained, indicating that the sandstone at the research location falls into the classification of high to low.

Mining roads play an important role in supporting the smooth running of mining activities, especially in the process of transporting materials. The bearing capacity of the soil as a road subgrade greatly affects the stability and resistance of the road to heavy equipment loads. This study aims to analyze the effect of the plasticity index and compaction parameters on the California Bearing Ratio (CBR) value, as well as to determine the thickness of the road layer based on the laboratory CBR value. Testing was carried out at the South Pit of PT. Bina Sarana Sukses site PT. Baramulti Suksessarana with a field test method using the Dynamic Cone Penetrometer (DCP) and laboratory tests such as proctor tests, Atterberg limit tests, and CBR tests on various variations of clay and sand soil mixtures. The results showed that increasing the plasticity index decreased the CBR value, while increasing the maximum dry density and decreasing the optimum water content increased the CBR value. Based on the laboratory CBR value, recommendations were obtained for the appropriate road layer thickness to ensure optimal bearing capacity for heavy equipment passing through the research area.

The implementation of coal mining activities with an open pit system at the end of its activities will leave behind the remains of former mining holes. Control of acid mine water is something that needs to be done during mining activities until the end of the mining process because acid mine water can cause a decrease in the quality of surface water and groundwater and have an impact on the survival of humans and biota that live on land and water. The initial characteristics of water using the floating treatment method of wetland, the pH, TSS, Fe, and Mn values ??of ex-mining lake water do not meet the quality standards of the Government Regulation of the Republic of Indonesia Number 22 of 2021. The ability of water hyacinth plants to increase pH for 25 days is quite good with an initial pH value of 4.13 to 7.34. For 25 days, the TSS parameter of water hyacinth plants is also good at reducing TSS levels with an initial value of 6 mg/L to 3 mg/L, the Fe parameter of water hyacinth plants is also good at reducing iron levels with an initial value of 1.06 mg/L to 0.34 mg/L, while the Mn parameter of water hyacinth plants is quite good at reducing manganese levels with an initial value of 1.13 mg/L to 0.32 mg/L.

One of the negative impacts of the mining process is acid mine drainage which is formed from the oxidation of minerals containing iron sulfur, such as pyrite (FeS2) and pyrothite (FeS) by oxidizers such as water and oxygen. To handle or control acid mine drainage, one way is to use activated carbon or often referred to as activated charcoal, which is a type of carbon that has a very large surface area. Charcoal is a porous solid that contains 85% to 95% carbon, produced from materials containing carbon by heating at high temperatures without oxygen (pyrolysis). Activated carbon made from palm shells is an adsorbent that can be used to treat coal mine acid water, so that the water meets standards for flowing into the environment. This study used concentration variants of 4 grams, 6 grams, 8 grams and contact times of 30 minutes, 60 minutes and 150 minutes. The results of this study show that the concentration of palm oil shell activated carbon adsorbent influences the reduction of iron (Fe) and manganese (Mn) metal levels as well as the pH conditions in acid mine drainage water. The higher the concentration and the longer the contact time, the more heavy metals are adsorbed, the contact time is the highest. The optimal concentration in this study was 150 minutes and the optimal concentration was 8 grams with physical activation.

In the process of designing mine slopes, drilling or tunneling, to determine the level of strength and brittleness factors of rock on a slope, it is necessary to carry out a uniaxial compressive strength test or indirect tensile strength test of the rock. Compressive strength testing is carried out to determine how long the rock maintains its strength or elastic properties when pressure is applied. This data can be used as information to understand the analysis of factors that influence the physical properties of rocks on the compressive strength of rocks from physical properties and compressive strength testing activities. and indirect tensile strength testing is carried out to determine the stress value contained in the rock. To determine the level of rock brittleness, it can be done by comparing the uniaxial compressive strength value and the indirect tensile strength value. This data can be used as information and reference for companies that will design a mine slope, drill and tunnel, how strong the strength and level of brittleness of rocks in areas dominated by sandstone. This research uses quantitative methods, so that to obtain accurate calculation data, testing methods are used in the form of uniaxial compressive strength tests and indirect tensile strength tests, in this case tested on sandstone samples obtained from 2 rock formations including the Pulaubalang formation and the Balikpapan formation, so that accuracy The test result values ??can be obtained well. And after testing, a comparison is made between the uniaxial compressive strength test value and the indirect tensile strength test to obtain the Brittleness Index value.Based on the observation results, it can be concluded that when the brittleness of the rock becomes greater, the performance of the cutting digger increases several times.