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Pemanfaatan bahan galian tambang berupa pasir besi di Indonesia cukup bervariasi. Pada industri semen dan industri pembuatan baja, pasir besi dalam bentuk bahan mentah atau raw material dimanfaatkan sebagai bahan campuran. Di Sulawesi Selatan tepatnya di sepanjang Pantai Tanjung Bayang ditemukan pasir pantai yang penyebarannya memanjang sepanjang arah pantai. Namun kadar Fe nya belum layak untuk diolah atau dijual lebih lanjut, baik untuk pemanfaatan pasir besi lokal sebagai bahan baku besi dan baja maupun untuk industri semen. Penelitian ini dilakukan dengan tujuan untuk mengetahui geokimia pasir besi menggunakan X-Ray Diffraction (XRD) dan X-Ray Fluorescence (XRF), menentukan kecepatan putar drum optimum dan mengetahui recovery yang optimum terhadap peningkatan kadar Fe pasir besi menggunakan Magnetic Separator. Metode penelitian dilakukan secara induktif menggunakan perpaduan antara penelitian kuantitatif dengan kualitatif, kesimpulan diperoleh dari perpaduan antara data lapangan dengan data hasil uji laboratorium. Hasil analisis XRD (X-Ray Diffraction) menunjukkan sampel pasir besi tersusun oleh mineral diopside (MgCaSi2O6), quartz (SiO2), magnetite (Fe3O4) dan hematite (Fe2O3). Hasil analisis X-Ray fluorescence spectrometry (XRF) memiliki Fe2O3 27,93%, SiO2 36,86%, Al2O3 20,317%, CaO 9,78%, TiO2 3,34%, MnO, K2O, V2O5, Cr2O3, ZrO2, SrO, ZnO, dan P2O5 masing-masing di bawah 1%. Hasil menunjukan bahwa persen berat menggunakan magnetic separator type dry-low intensity drum dengan variasi kecepatan putar 200, 250 dan 300 rpm masing-masing 79,25%; 44,17% dan 46,04% sedangkan kadar Fe2O3 masing-masing 29,98%, 49,08% dan 44,15% dengan recovery 85,08%; 77,62% dan 72,78%. Recovery Fe2O3 optimum diperoleh pada kecepatan 250 rpm.

Proses penambangan sumber daya nikel di PT Mandiri Mineral Perkasa terdapat permasalahan berupa terjadi selisih kandungan nikel antara data bor dengan data hasil penambangan. Penelitian ini bertujuan untuk mengetahui faktor penyebab terjadinya perubahan nilai kadar nikel hasil pengeboran dan hasil penambangan dalam rangka mencari upaya pencegahannya. Penelitian dilakukan dengan menghitung rata-rata kandungan nikel hasil data bor dengan hasil penambangan untuk mengetahui perbedaan selisih yang diperoleh dan melakukan survey tahapan proses penambangan untuk mengetahui faktor-faktor penyebab terjadinya perbedaan kadar nikel. Hasil dari penelitian menunjukan bahwa nilai kadar rata-rata nikel hasil pengeboran sebesar 1,74%, sedangkan hasil dari aktivitas penambangan diperoleh nilai kadar rata-rata sebesar 1,60% atau terjadi selisih kadar Ni 0,14%. Berdasarkan hasil pengamatan faktor-faktor penyebab dari perubahan kadar nikel diduga berasal dari aktivitas pengerukan lantai stockpile yang kurang baik, adanya genangan air pada stockpile, kondisi bucket pada excavator yang kurang bersih, kondisi karung sampel yang kurang bersih dan kesalahan aktivitas pada saat sampling dan kesalahan pada aktivitas preparasi sampel.

In general, the combustion of coal containing high sulfur and ash causes negative environmental problems such as acid rain and the emission of oxides of sulfur. Coal flotation is one of the most effective methods for desulfurizing and deashing raw coal with high ash and sulfur contents before burning coal. In this study, a coal sample collected from East Kalimantan Province, Indonesia was subjected to flotation by using diesel oil as collector and pine oil as frother. The experimental results showed that 24% of the total sulfur was eliminated from coal. Also, the calorific value of coal increased from 5,486 cal/g to 5,535.38 cal/g. However, the volatile matter and ash content of coal was eliminated.

Indonesia is a country with a tropical climate that allows for high levels of weathering. Bauxite is the result of weathering rocks that have high aluminum content, low iron content, and little quartz content. The formation of bauxite deposits is controlled by source rock which is rich in Al element, tropical climatic conditions, and geomorphological conditions that allow the formation of the accumulation of weathered source rock products. The altered silicate minerals due to weathering result in the silica element being released from the crystal bonds and some iron are released so that the aluminum element is concentrated as a residual precipitate. X-ray diffraction (XRD) analysis on 16 bauxite samples which are estimated to represent the overburden horizon, bauxite ore horizon, clay horizon, and source rock to establish the mineral composition of bauxite. Mineral groups in the overburden horizon, bauxite ore horizon, and clay horizon are alumina, iron, titanium, silicates, carbonates, sulfides, and sulfates, while mineral groups in source rock are iron, titanium, silicate, sulfide, and sulfate. The type of bauxite in the study area is gibbsite bauxite based on the dominant appearance frequency of gibbsite compared to mineral corundum as an alumina group.

Lateritic bauxite are the products of intense weathering of rocks. It is largely controlled by bedrock type, time, climate (rainfall), and geomorphology. It is located in Kenco area, Landak district, West Kalimantan Province which the rest of the development of Cretaceous volcanism consisting of the island of Borneo Volcanic Formations Mensibau with unit members Granodiorite, quartz diorite and diorite, and the Formation of the Kingdom Volcanic Andesite-trachite units and Formations of alluvium and swamp sediment quarter. Bauxite deposits of Kenco area in Landak are investigated to determine the characteristics of rocks using petrographic analysis. Petrographic analysis aims to determine mineral content and type of source rock based on Travis classification (1955). The results of 15 thin sections showed that aluminum-bearing minerals consisted of orthoclase, plagioclase, and biotite which are the type of source rock are granodiorite, granodiorite porphyry, gabbro porphyry, and basalt porphyry based on Travis classification (1955).

The fuel consumption rate rises and is expected to increase continuously, causing fuel supplies to be depleted and this condition forces the community to find alternative sources of fuel such as bio-briquettes. The waste of canary shells is widespread in Indonesia and can be used as an alternative energy source of bio-briquette making. There is a need for study on the influence of raw materials bio-briquette mixture of coal and canary shells against the value of calories produced. Bio-briquette making in this study have been done using canary shell and coal with a composition: (250 gr coal/canary shell: 12.5 tapioca starch: 50 ml water). Before briquette making, the canary shell samples are pirolysed and a grain-size reduction is performed on both of coal and canary shells. Canary shell and coal bio-briquettes are made with four variations (types). The types of bio briquette are: type I of bio-briquette with a composition of 250 gr (coal) + 12.5 gr (tapioca starch) + 50 ml (water). Type II of bio-briquette with a composition of 250 gr (canary shell) + 12.5 gr (tapioca starch) + 50 ml (water). Type III of bio-briquette with a composition of 62.5 gr canary shell + 62.5 gr coal + 12.5 gr (tapioca starch) + 50 ml (water). Bio-briquette type IV consist of 93.75 gr (canary shell) + 31.25 (coal) + 12.5 gr (tapioca starch) + 50 ml (water). After preparation, all bio briquettes are analyzed to determine the caloric value. The results of the study shows bio-briquette type I has a caloric value of 5,539 kcal/g, bio-briquette type II produces the highest calorie value of 6,354 kcal/g, and bio-briquette type III is 6,020 kcal/g. Further more bio-briquette Type IV indicate caloric value of 6,096 kcal/g. Bio-briquette type IV is the most recommended in the utilization because of the goal of this study is to use canary shell as an alternative fuel.

Coal is one of the important energy sources in the world. It has been part of the important roles for centuries, not only for generating electricity but also the main fuel for steel and cement production as well as other industrial activities. However, the quality of the coal is generally too low for the practical, economical utilization. High sulfur and ash contents come up as one of the barriers in the productive usage of indigenous coal. Clean coal technology such as coal biobeneficiation can appear as a panacea for upgrading the coal reserves with high sulfur and ash contents. In the current study, the removal potential of the sulfur and ash content from coal of Kalimantan, Indonesia was investigated by using the bacterium Pseudomonas moraviensis. It was reported for the first time that the bacterium had the capability to remove about 17.37% of total sulfur and ash content from the coal. The results revealed that the bacterium Pseudomonas moraviensis used in this study could remove sulfur and ash content from the coal and could thus be used in the pre-combustion operation with appropriate arrangement.