Indonesian Mining and Energy Journal, Nov 30, 2023
ABSTRAK-Ketercapaian produksi merupakan salah satu indikator keberhasilan kegiatan operasional pe... more ABSTRAK-Ketercapaian produksi merupakan salah satu indikator keberhasilan kegiatan operasional penambangan. Pemenuhan indikator ini umumnya disebabkan faktor-faktor operasional peralatan tambang, khususnya pada alat gali dan alat muat. Salah satu faktor ini adalah kesediaan alat tambang, yang didalamnya terdiri dari ketersediaan fisik (PA), ketersediaan mekanis (MA), dan efektif pemakaian (EU). Rendahnya nilai parameter umumnya berdampak pada ketidaktercapaian target produksi. Pada penelitian ini menggunakan metode evaluasi kuantitatif, dimana dilakukan evaluasi pada jumlah kebutuhan alat yang digunakan untuk mencapai target produksi overburden, data yang dibutuhkan pada penelitian, waktu siklus dari alat muat dan angkut. Dilakukan simulasi pada waktu standby alat untuk mengoptimalisasikan hasil produksi dari alat yang digunakan. Perhitungan terhadap produktivitas dan produksi tercapai dilakukan pada skenario sebelum dan setelah peningkatan kinerja. Sebagai indikator keberhasilan, faktor keserasian (MF) juga dihitung pada kedua skenario. Pada akhir studi, dilakukan perhitungan kebutuhan peralatan untuk melihat pengaruh peningkatan kinerja pada kebutuhan peralatan tambang. Setelah dilakukan pengolahan data yang didapat dapat kesimpulan bahwa optimalisasi waktu standby alat tidak cukup untuk mencapai target produksi overburden, dan dibutuhkan satu unit tambahan pada alat angkut. Kata kunci: produksi, overburden, standby, excavator dan dumptruck ABSTRACT-The achievement of production is one of the indicators of the success of mining operational activities. The fulfillment of this indicator is generally influenced by operational factors of mining equipment, especially excavation and loading equipment. One of these factors is the availability of mining equipment, which includes physical availability (PA), mechanical availability (MA), and effective utilization (EU). The low values of these parameters generally has an impact on the failure to achieve production targets. In this study using a quantitative evaluation method, which evaluates the number of equipment needed to achieve the overburden production target, the data needed in the study, the cycle time of the loading and transport equipment. Simulation is carried out at the standby time of the tool to optimize the production results of the equipment used. Calculations for achieved productivity and production are carried out in scenarios before and after performance improvement. As a success indicator, the compatibility factor (MF) is also calculated in both scenarios. At the end of the study, equipment requirements are calculated to assess the impact of performance improvement on mining equipment needs. After processing the data obtained, it can be concluded that optimizing the standby time of the equipment is not enough to achieve the overburden production target, and an additional unit is needed for the conveyance.
Galena is a potential source of lead (Pb), which has many used for lead batteries. Indonesia is a... more Galena is a potential source of lead (Pb), which has many used for lead batteries. Indonesia is a country with potential sources of galena mineral. This investigation showed Pb extraction of 0.274 % using acetic acid leaching method with 1.0 M acetic acid at 50 o C from galena concentrate. This study showed remarkable enhancement of Pb extraction until 8.96 % applying electrodeposition method using 1.0 M acetic acid at 50 o C. Varied acetic acid concentrations were applied for 1.0 M, 3.0 M, 5.0 M, and 7.0 M and varied temperatures were applied in this study for 50 °C, 65 °C, and 80 °C. The percentage of Pb extraction showed a consistency with the reduction of % Pb extraction with increasing acid concentrations and increasing temperatures. This findings is assumed to be related to exothermic PbS dissolution shifted to decreasing Pb(II) ion concentration and ion pair formation retarding Pb dissolution. The percentage of Pb from leaching process was determined by AAS (Atomic Absorption Spectrophotometer), while the percentage of Pb by electrodeposition method was determined from quantity of Pb deposit on cathode of an electrochemical cell. This investigation shows a significant breakthrough for enhancement of Pb recovery from galena mineral.
PT X is a limestone mine located in the district of Rembang, Central Java, which plans to expand ... more PT X is a limestone mine located in the district of Rembang, Central Java, which plans to expand and dig deeper. To ensure that the slope is stable, geotechnical study is needed. However, if it is done in 2 dimensional (2D) the result might not always be representative. This research was conducted to determine the stability of single slope using three dimensional limit equilibrium method (3D LEM). The data was collected by doing geotechnical mapping of the drill core sample and conducting laboratory test of rock samples, i.e. the test of physical and mechanical properties of rocks. The result shows that there is a significant difference between 2D and 3D FoS. The volume of sliding is also presented.
INDONESIAN JOURNAL OF URBAN AND ENVIRONMENTAL TECHNOLOGY
Land subsidence has long occurred around the Special Capital Region of Jakarta. It is important t... more Land subsidence has long occurred around the Special Capital Region of Jakarta. It is important to know and deal with Land subsidence events which also cause various negative impacts. Aim: When large amounts of groundwater are withdrawn from certain types of rocks, such as fine-grained sediments, land subsidence occurs. The rock compacts because the water helps to keep the ground in place. When the water is removed, the rocks collapse in on themselves.The immediate impact is the building collapse around the Kota Tua of DKI Jakarta. Methodology and Results: The research method used is a quantitative descriptive survey method by observing the amount of land subsidence that occurs in the Kota Tua area and its surroundings. The results showed that there has been a vertical land subsidence that varies between 20-60 cm. Based on the results of the resistivity values and coordinates plotted on the Regional Geological Map (Jakarta and Kep Seribu), the research location is classified into Li...
This article aimed to separate ilmenite (FeTiO3) mineral from tin tailing applying a single split... more This article aimed to separate ilmenite (FeTiO3) mineral from tin tailing applying a single splitter IRMS (Induced Roll Magnetic Separator). Ilmenite mineral is the substantial main source for TiO2. This work used air table middling for feeding. The mineral components of middling feeding from air table using grain counting analysis were found as follows: cassiterite (48.61%), ilmenite (21.36%), monazite (18.56%), pyrite (4.60%), zircon (5.85%), quartz (0.71%), anatase (0.27%), and tourmaline (0.02%), It was found that electrical current and opening of single splitter affected the degree of separation addressing to ilmenite recovery and ilmenite grade. The finding showed that current of 15 Ampere and single splitter with opening 4.25 cm yielded ilmenite recovery more than 74%. The high grade ilmenite (90.46 %) and recovery of 29.38% was obtained using 5 Ampere with single splitter opening of 1.0 cm. Up to date, the study on ilmenite separation from tailing only focused on the effect...
International Journal of Innovation in Mechanical Engineering and Advanced Materials
This article aims to present the application of acetic acid and sulfuric acid for lead (Pb) extra... more This article aims to present the application of acetic acid and sulfuric acid for lead (Pb) extraction from galena concentrate applying roasting (600oC and 60 min.) and peroxide oxidant (0.5 M) for 60 min. leaching process. Nowadays, lead has been broadly applied for batteries, besides for PVC tubes, chemicals, paint color, and alloys for joint. The peroxide increases the percentage of Pb extraction. This study shows the effect of acid concentrations (1.0 M, 1.5 M, and 2.0 M), temperatures (30, 50, and 70oC), and stirring speed (200, 400, and 600 rpm) on Pb extraction from galena. A particle size of galena ≤ 200 mesh after roasting has been used for leaching process. AAS has been used to determine Pb concentration in solution after leaching process. This study shows that acetic acid is a better leaching agent rather than sulfuric acid due to lead sulfate precipitation. Optimization result shows leaching with acetic acid achieved 35.64 ppm Pb extraction using 2.0 M acetic acid, 50oC...
Saat ini dalam perencanaan pemboran eksplorasi mineral dan batubara masih banyak pertanyaan ten... more Saat ini dalam perencanaan pemboran eksplorasi mineral dan batubara masih banyak pertanyaan tentang bagaimana menentukan jarak lubang bor yang optimal untuk klasifikasi sumberdaya, kareana penentuan jumlah lubang bor akan sangat berkorelasi denggan pengeluaran dana eksplorasi. Solusi untuk menjawab pertanyaan permasalahan tersebut adalah dengan meningkatkan pengetahuan dan pemahaman perencana eksplorasi mengenai analisis jarak lubang bor untuk klasifikasi sumberdaya, khususnya dengan menggunakan metode geostatistik. Dalam hal ini teknik yang digunakan adalah varians estimasi global. Pelaksanaan pengabdian kepada masyarakat berupa worksop dilakukan dengan berbegai tahap, meliputi tahap perencanaan, workshop dan evalusi kegiatan. Hasil kegiatan ini dapat meningkatkan pemahaman dan pengetahuan para peserta tentang konsep geostatistik dan penenetuan jumlah lubang bor yang optimal. Kesimpulan dari workshop yang dilaksanakan yaitu hampir seluruh peserta dapat menerima materi yang disa...
I n time, water wears down the stone , If you don ' t believe the veracity of the above statement... more I n time, water wears down the stone , If you don ' t believe the veracity of the above statement, visit the Grand Canyon. Law book publishers should issue catalog cards with their sets. For example, suddenly, without notice, the West Publishing Company began sending us volumes of the Federal Practice Digest, second series. (Which we. arc grateful for.) Why should 200 to 300 catalogers each individually catalo g this set? Why couldn't West send us a set of catalog cards when they sent us the book? The printin g cost to them is minimum. The next time your West salesman or woman visits you, bug him/he r about it. Better still, write
PT Roda Jaya Sakti merupakan suatu perusahaan yang bergerak di bidang kontraktor tambang baik ska... more PT Roda Jaya Sakti merupakan suatu perusahaan yang bergerak di bidang kontraktor tambang baik skala besar maupun skala kecil, lokasi penelitian berada di Morowali, Sulawesi Tengah dan mineral yang akan ditambang berupa mineral nikel. PT Roda Jaya Sakti menyediakan alat – alat berat untuk kebutuhan penambangan. Kegiatan pertambangan tidak terlepas dari kegiatan alat gali muat dan alat angkut, di PT Roda Jaya Sakti kegiatan gali muat tidak optimal dikarenakan keserasian alat di PT Roda Jaya Sakti tidak efisien yang mengakibatkan tidak tercapainya target bulanan, oleh sebab itu akan di lakuan penelitian di bidang alat angkut mineral Nikel dengan metode evaluasi dan simulasi agar tercapai keserasian antara alat angkut dengan alat gali muat dengan evaluasi kerja alat aktual serta dilakukan perhitungan bahan bakar yang terbuang saat alat angkut menunggu sehingga didapatkan tingkat efisiensi kerja yang maksimal, dan juga hasil penelitian yang diharapkan meminimalisir biaya bahan bakar pada...
3RD INTERNATIONAL POSTGRADUATE CONFERENCE ON MATERIALS, MINERALS & POLYMER (MAMIP) 2019, 2020
Cohesion (c) and angle of internal friction(ϕ) are one of the inseparable geotechnical parameters... more Cohesion (c) and angle of internal friction(ϕ) are one of the inseparable geotechnical parameters in the stability analysis of mining slopes. The estimation process is needed in knowing the distribution or zoning of geotechnical parameters. In this study, the estimation process uses a geostatistical method where the data used collected from PT Bukit Asam Tbk. in the form of geotechnical drill data, laboratory analysis results of rock mechanics (c, ϕ) and drill logs. The data is processed into one database which includes the coordinates of information points (easting and northing), lithology and geotechnical parameters of intact rock (c, ϕ). Then form a variogram using a range of distance, nugget effect and sill that is tried to get the suitability of the data, seen from cross validation so that the estimated results are expected to be accurate and reliable. The accuracy and classification of the level of confidence of the kriging estimation results are grouped based on the distance between the information points obtained through variogram analysis by dividing the sill into three parts namely 1/3, 2/3 and 3/3 sill. In this study, the data is considered accurate and has a high level of confidence if it has a distance between information points 100-200 m, has a medium level of confidence if the information point is 200-400 m distance and has a low level of confidence if the distance between information points 400-700 m.
The effect of maximum iteration using 3 dimensional limit equilibrium method in open pit mine
IOP Conference Series: Earth and Environmental Science, 2021
Nickel ore mines have a high potential of landslides due to their weak material base, which consi... more Nickel ore mines have a high potential of landslides due to their weak material base, which consists of soil. It is caused by the increase of soil density in rain conditions, leading to decreased soil shear strength (c) and internal friction angle (ϕ). This research aims to determine the optimum value of the maximum iteration number based on the Cuckoo Search and Particle Swarm Optimization search method. In this research, the slope is analyzed using the 3 Dimensional limit equilibrium method “Simplified Bishop,” a slope stability analysis method that uses the principle of static equilibrium. Alongside this method, the Cuckoo Search and Particle Swarm Optimization is adopted. The Cuckoo Search and Particle Swarm Optimization are metaheuristic optimization techniques used as the slipped surface search method. Series of 3-dimensional limit equilibrium computation is performed using different amounts of nests in the cuckoo search method and different particle values and maximum iterati...
The judging and ranking of papers were based on numerical grading system that involved three elem... more The judging and ranking of papers were based on numerical grading system that involved three elements in the final score of the paper: (1) scientific and technical quality of the paper (up to 50 %), (2) impact on the profession and society (up to 30 %), and (3) quality of figures and tables (up to 20 %).
IOP Conference Series: Materials Science and Engineering, 2019
The occurrence of landslides on the slopes due to a decrease in shear strength in the area of lan... more The occurrence of landslides on the slopes due to a decrease in shear strength in the area of landslides in the limestone hills of Kaliwadas, Kebumen, Central Java, causes public facilities to be damaged and disrupting the activities of everyday citizens. Factors that influence rock shear strength are cohesion value and internal friction angle, while mineralogy and grain size is one of the factors derived from the environment which also affects the shear strength value. This study aims to determine the effect of mineral composition and grain size on rock shear strength. A number of rock samples were taken from the study site to be prepared, cylindrical samples for direct shear and petrographic strength tests with thin incision samples. Direct shear test results provide cohesion values and deep shear angles in limestone with peak and residual conditions of 0.22 Mpa and 39.73 ° respectively; 36.61 kPa and 29.28 ° while in claystone 67.86 kPa and 25.36°; 13.41 kPa and 16.17 °. Petrogra...
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Papers by Irfan Marwanza