Analisis Mineralogi dan Kimia Dolomit Kabupaten Bone Bolango, Provinsi Gorontalo

Characterization of dolomite samples from Bone Bolango, Gorontalo Province have been performed with the objective to find out their mineralogical and chemical compositions. Observation and mineral analyses were carried out by means of microscopy and X-ray diffraction methods respectively; whereas chemical composition was determined by using X-ray fluorescence spectrometer. Result of XRD analysis shows that samples contain dolomite [CaMg(CO3)2], calcite [CaCO3] and [SiO2]. The proportion of dolomite is about 60.4% in average and its presence is as replacement of calcite in bioclast components and matrices in the rock. Dolomite crystals are characterized by mosaic texture with euhedral – subhedral in shapes. Spacially, dolomite content increase from west to the east of study area. The XRF analysis reveals that dolomite samples contain MgO ranging between 8.07 and 20.78% while CaO ranges between 30.04 and 56.13%. The SiO2 concentration ranges from 3.50 – 7.55%; whereas Al2O3 ranges from 1.07 – 1.84%. The average MgO content of dolomite about 12.89% can be categorized as calcium dolomite. Dolomite within the study area can be used directly in agriculture sector, but it less suitable as raw materials in glass, ceramic and refractory industries because the average content of MgO is less than 17%. However, it can be increased of their MgO with the application of selective mining or beneficiation process.

Planning of ore shotpileselective mining by the geoinformation technologies in the condition of the Ferrexpo Eristovo Mining

Purpose. Develop method for predicting the displacement of ore contours in the shotpile after the explosion to planning the ore raw materials selective mining at the development of iron ore quarries. Research methodology. Actual surface measurements were used to determine the loosening coefficient for individual sections of rock mass collapse. The analytical methods were used to calculate the planes of the face sections before and after the explosion. Determination of the predicted position of the contours of iron ore in the shotpile was performed by the method of graphical selection. The results. It is established that the loosening coefficient of the rock is variable in individual parts of the ore block and can be used to determine the predicted position of the ore contour. The main difference of proposed predicting methods consist in establish the expected position of contact of rocks and geological markers in the field, which will allow in the regular mode to control the development of the face by a pit geologist. Scientific novelty. The dependence of the predicted position of the ore contour in the rock mass shotpile on the method of actual survey of the pit surface "before" and "after" the explosion when performing geometric constructions is established. Determined that the proposed method of prediction allow to minimize costs in the form of insignificant organizational changes at planning observance of qualitative indicators, reduction of risks and dangers at geological works is provided, and also efficiency of works on short-term planning system in rock mass shotpile increases. Practical value. A method for determining the position of the ore contour in the rock mass shotpile has been developed. The possibility of using the predicted position of the ore contour for planning the selective mining of ore shotpile has been established. The expected economic effect of the proposed solutions is achieved by reducing the cost on processing rocks and low-grade ore when they fall on the crusher due to erroneous classification during the selective development of ore deposits.

DETERMINATION OF THE RATIONAL BACKFILLING PARAMETERS DURING SELECTIVE EXTRACTION TECHNOLOGY OF THIN COAL SEAMS

Purpose. Substantiation of the backfill massif parameters in fully mechanized selective mining thin coal seams, taking into account the influence of technological and mining-and-geological conditions. Methods. The integrated approach which includes the analysis and generalization of scientific developments in the field under study, analytical and numerical methods for determining technological parameters is used in the work. Findings. The results of studies of the influence of complex technological and mining-and-geological conditions on filling massif parameters while selective mining are given in the paper. Using the example of numerical calculation methods for the selected initial characteristics of the mined coal seam the following trends are revealed: the shrinkage value of the filling material Eв from the ultimate rock strength σст and the relative density γв; the length of the filling mined-out space lз and the size of the undercut rocks mпр, the filling density γв and the technological gap Δhтех; the initial height of the filling massif formation hЗ and the effective seam thickness mеф from the support resistance Pк and the rock strength of the filling material σст. Originality consists in the determination of the change regularities in the roof subsidence and deformation of the filling massif from the technological parameters of the site and the face support while effective coal seam development by technological scheme of selective coal extraction. Practical implication. The research results can be used in the design of technological schemes for coal mining with backfilling and leaving waste rocks in the worked-out area. Key words: backfilling of worked-out space, selective technology, parameters, regularities.

Analisis Penurunan Capaian Target Produksi Bijih Nikel Menggunakan Metode Fault Tree Analysis di PT Ifishdeco Provinsi Sulawesi Tenggara

Abstrak Proses produksi berarti menghasilkan suatu produk yang bernilai guna. Dalam suatu perusahaan pertambangan, produksi merupakan hal yang sangat penting, sehingga diperlukan perencanaan yang matang. Perusahaan menargetkan jumlah bahan galian yang akan diproduksi baik dalam jangka panjang, menengah maupun jangka pendek. Operasi produksi PT. Ifishdeco menggunakan bantuan alat gali muat excavator Komatsu PC 300 dimana terjadi penurunan produksi bijih nikel sebesar 19,94%. Target produksi sebesar 149.934 mt, namun capaian produksi hanya sebesar 116.603mt. Oleh karena itu, penelitian ini dilakukan untuk mengetahui faktor utama dan nilai probabilitas penyebab turunnya capaian produksi. Salah satu metode yang dapat digunakan untuk menganalisis faktor utama penyebab penurunan capaian produksi adalah menggunakan Fault Tree Analysis (FTA). Persamaan logika top down dari Fault Tree Analysis disubstitusi ke dalam aljabar Boolean hingga diperoleh minimal cut set. Minimal cut set merupakan persamaan akhir yang merincikan top down. Top event penurunan capai target produksi memiliki empat top down, yaitu faktor pengisian, kesiapan fisik alat, efektivitas kerja, dan waktu edar alat gali muat. Berdasarkan nilai probabilitas basic event tertinggi yang bernilai 1, maka faktor utama penyebab penurunan capaian produksi adalah dari faktor umur pakai alat tua, penjadwalan perawatan tidak teratur, kualitas alat buruk, dan proses selective mining. Abstract Analysis of Decrease in Nickel Ore Production Targets Using the Fault Tree Analysis Method in PT Ifishdeco, Southeast Sulawesi Province. Production process meant produce product with beneficial value. At the mining company, production was very important, so it needed to be well-planned. Company was making target amount of digging material to be produced in long term, middle term, and short term. Production operation at PT Ifishdeco utilized digger loader equipment namely excavator Komatsu PC 300. There was decreasing in nickel ore production of 19,94%. Production target was 149,934 mt, but the company was only able to meet 116,603 mt. Objective of this study was to know main factor and probability value which caused the low production performance. One of methods to be used to analyze the main factor was Fault Tree Analysis (FTA). Top down logical equations of Fault Tree Analysis was substituted into Boolean algebra to get minimal cut set. Minimal cut set was a formula of the top down and used to calculate probability. Top event of the decreasing of the production target had four top downs which were filling factor, mechanical availability, effectivity of use, and cycle time of digger loader. Based on the highest probability of basic event which value was equal to 1, the main factor caused the decreasing of productivity were lifetime of equipment, unscheduled of maintenance, low quality of equipment, and selective mining. Kata Kunci: Excavator, Work Effectivity, Boolean, Cut Set, Probability

ROBOMINERS - Resilient Bio-inspired Modular Robotic Miners

<p>The Horizon 2020 ROBOMINERS project (Grant No. 820971) studies the development of an innovative technology for the exploitation of small and difficult to access mineral deposits. A bio-inspired reconfigurable robot with a modular nature will be the target of the research efforts. The goal is to develop a prototype that will be able to mine under different conditions, such as underground, underwater or above water. ROBOMINERS’ innovative approach combines the creation of a new mining ecosystem with novel ideas from other sectors, particularly robotics. This covers both abandoned, currently flooded mines not accessible anymore for conventional mining techniques; or places that have formerly been explored, but whose exploitation was considered as uneconomic due to the small-size of deposits, or their difficulty to access. </p><p>The ROBOMINERS concept follows a 5-step approach: 1) Robot parts (modules) are sent underground via a borehole; 2) Self-assemble to form a fully functional robot; 3) Robot detects the ore deposit via sensing devices; 4) Using ad-hoc production devices, it produces slurry that is pumped out; 5) Ability to re-configure on-the-job. </p><p>Specifics include: 1) Construction of a fully functional modular robot miner prototype following a bioinspired design, capable of operating, navigating and performing selective mining; 2) Designing a mining ecosystem of expected future upstream/downstream raw materials processes via simulations, modelling and virtual prototyping; 3) Validation of all key functions of the robot-miner to a "Technology Readiness Level" of TRL4; and  4) To use the prototypes to study and advance future research challenges concerning scalability, resilience, re-configurability, self-repair, collective behavior, operation in harsh environments, selective mining, production methods, as well as for the necessary converging technologies on an overall mining ecosystem level. These specific goals will deliver a new mining concept, proven in laboratory conditions, capable of changing the scenario of mineral exploitation.</p><p>Powered by a water hydraulic drivetrain and artificial muscles, the robot will have high power density and environmentally safe operation. Situational awareness and sensing will be  provided by novel body sensors, such as artificial whiskers that will merge data in real-time with real-time production mineralogy  sensors that, together with specific production tools, will enable selective mining, optimising the rate of production and selection between different production methods. The produced mineral concentrate slurry is pumped to the surface, where it will be processed. The waste slurry could then be returned to the mine where it will backfill mined-out areas.</p><p>ROBOMINERS will deliver proof of concept for the feasibility of this technology line, which can enable the EU to have access to mineral raw materials from otherwise inaccessible or uneconomic domestic sources, decreasing European dependency on imports from third-party sources, as envisaged by the raw materials policy. Laboratory experiments will confirm the Miner’s key functions, such as modularity, configurability, selective mining ability, and resilience under a range of operating scenarios. The Prototype Miner will then be used to study and advance future research challenges concerning scalability, swarming behaviour and operation in harsh environments.</p>

Tracking Cobalt, REE and Gold from a Porphyry-Type Deposit by LA-ICP-MS: A Geological Approach towards Metal-Selective Mining in Tailings

High-resolution mineral characterization performed on mine material from a giant porphyry copper deposit shows that critical and precious metals, such as cobalt, lanthanum, gold, silver, and tellurium, are concentrated in pyrite in the form of visible micro-inclusions, invisible mineral nano-inclusions, and trace metals in the mineral lattice. Visible and invisible inclusions consist of Ag-Au-Te sulfosalt and monazite-(La) particles. Trace metal concentrations grade up to 24,000 g/t for cobalt, up to 4000 g/t for lanthanum, and up to 4 g/t for gold. Pyrite, considered a waste material, is removed from the valuable copper ore material and sent to the tailings. Thus, tailings with high contents of pyrite can represent a prime target to explore for critical metals in the porphyry copper mining operations, transforming it into a new source of supply for critical metals. We propose that high-resolution mineral characterization is the key to evolve from a quasi-single-metal (copper) operation to a multi-metals business by developing metal-selective mining. To address this challenge, we coined the Metal-Zone concept to identify zones enriched in a specific metal within a mineral deposit, instead of zones enriched in an ore mineral.

Features of choosing the schemes for selective mining of ores and justifying their rational parameters while using heap leaching schemes for processing

The article presents data from theoretical and experimental studies related to the search for a solution to an urgent geotechnological problem - selective mining of standard quality ore, substandard and diluted ores, taking into account the peculiarities of their processing by heap leaching. For complex-structural large-scale ore deposits of the stockwork morphological-structural type, multilevel heterogeneity is typical. The morphology and structure of the objects of direct extraction - ore bodies within the production blocks - vary significantly. The expediency of selective mining and separate heap leaching (or heap oxidation and leaching) of gold and copper from conditioned ores of various geological and technological types and grades is justified. In addition, it is advisable to selectively extract and separately process by heap leaching or flux in a controlled manner before it off-balance and diluted ores, as well as mineralized overburden and tailings of high-grade ores.

The role of digital simulation in assessing and reassessing the potential of complex coal deposits

The article addresses the increasing complexity of mined or prospective coal deposits. The paper analyses the role of digital simulation in operation assessment and reassessment of the potential of complex in structure coal deposits for more accurate understanding their investment attractiveness, reliability of knowledge on quantity and quality of the reserves. The article stresses the objective need to take into account the realities of the VUKA-world, when companies have to react rapidly to changing of external conditions by adapting organizational and technological measures as much as possible to the constantly overestimated potential of the raw material base. It is of note that reserves should be assessed in accordance with international requirements in the light of the increasing number of parameters for management. The complexity of the structure, the geomechanical heterogeneity of the rock mass, the mineral content of the impurities in the coal, its caking capacity, oxidation and enrichment are taken into account in the estimation. The paper presents the measures to increase the level of utilization of geological potential through the application of selective mining and the control of different quality coal streams in preparation for enrichment and during primary processing.