Coal preparation

Heat transfer simulation within heating furnaces is of great significance for prediction and control of the performance of furnaces. In this paper, a set of models is proposed to solve heat transfer problems in a loaded furnace. Furthermore, a 2-dimensional algorithm based on a finite difference method is presented. The heat transfer models are integrated with a furnace model to simulate the heating process of workpieces. Temperature variation of the workpiece with time is predicted by the system. An experiment is carried out for validation of the system. Themain objective of this work is to evaluate the behavior of a heated enclosure, when variable radiant panels are introduced. Experimental investigation shows that their efficiency depends on their position.

A combination of semicoking followed by a permanent roll magnetic separator (PERMROLL) has been used for the upgrading of a Turkish low-rank lignitic coal. The lignite samples were subjected to a low temperature carbonization process at 600°C and then upgraded by the PERMROLL. Under optimum conditions, carbonization of lignite particles in −9 + 0.5 mm size range which contained 12.18 wt.%

In line with the objectives to reduce dependency on foreign energy resources and increase the share of domestic coal in energy supply, significant developments took place in Turkey's coal sector in recent years. As a result of recent intense exploration and reserve development works, coal reserves reached to nearly 20 billion tons. Saleable coal production exceeded 70 Mt in 2017 and 80 Mt in 2018. The R&D studies in the field of clean coal technologies have gained speed and, in parallel with these developments, coal preparation plants have become widespread especially in the last 15 years. In this study, the coal preparation industry in Turkey is summarised. In this respect, the coal production, imports and consumptions of the country have been reviewed and major coal preparation plants, their capacities and technologies, annual washed coal production figures and R&D studies on clean coal technologies are given briefly.

Altın zenginleştirme, gümüş zenginleştirme, bakır zenginleştirme, demir zenginleştirme, antimuan zenginleştirme, molibden zenginleştirme, Alüminyum zenginleştirme, nikel zenginleştirme, otoklav liçi, tank liçi, yığın liçi, gravite ile zenginleştirme, sallantılı masa, kromit zenginleştirme tesisi,

Laporan ini merupakan laporan Prakerin (Praktek Kerja Industri) yang dilakukan siswa SMKN 1 Bontang di PT. Carsurin Cabang Bontang pada tahun 2013. Dimana dalam laporan ini berisi rangkuman kegiatan siswa selama menjalani Prakerin di PT. Carsurin Cabang Bontang, selain itu laporan ini berisi studi khusus yang dilakukan ada saat melakukan Prakerin, dengan judul Studi Khusus "Pengaruh Nilai Moisture Terhadap Nilai Ash Content dan Volatile Matter". Laporan ini dibuat sebagai wujud pertanggungjawaban siswa terhadap Prakerin yang telah dilaksanakan, baik kepada PT Carsurin Cabang Bontang maupun kepada SMKN 1 Bontang. Adapun laporan ini disusun oleh :
1. Rike Dominta Aprianti Manik
2. Rina Dwi Safitri
3. Karina Ananda Putri
4. Hardiansyah

Direct liquefaction of low-rank Malaysian coal from the Mukah Balingian (MB) area was successfully carried out in a 1000 ml high-temperature (360–450°C) high-pressure (4–13 MPa) batch-wise reactor system using tetralin as hydrogen donor solvent. The results indicated that the percent coal conversion obtained were in the range of 31–90%. At optimum conditions of 450°C and 4 MPa, the oil + gas, asphaltene and preasphaltene of the coal extract were 80%, 7%, and 2%, respectively. It was observed that heat plays an important role in comparison to pressure in contributing to high coal conversion, oil yield, and organic properties of the residues. The high coal conversion and oil yield correlate well with the high content of reactive macerals, i.e., vitrinite and exinite, in the coal. Other parameters that were also investigated include the effect of reaction time (0–120 min) and coal-to-solvent ratio. A high yield of asphaltene and preasphaltene was obtained at the longest reaction time (i.e., 120 min). Coal conversion and oil yield increase with increasing in coal-to-solvent ratio, with the optimal ratio being 1:5.

Turkish Coal Enterprises since 1979. The lignite which has an average heat value of 2000 kcal/kg is produced to feed Orhaneli 1x210 MW Thermal Power Plant. Having low heat value of lignite coal, has difficulties in acquiring the appropriate heat values and low ash content to feed the thermal power plant and marketing. In the last twenty five years, in Western Europe and particularly in Germany, large appliances, including washing facilities equipped with automatic control systems have been constructed instead of large number of low-capacity old coal plants. Therefore, in order to obtain the appropriate heat value of run of mine, not as much as large appliances as Europe or TKI's other coal washing plants; Orhaneli's simple coal washing plant facility is planned to work for various coal seams. The run of mine is planned to directly put into the bunker of 150 t/h capacity. Accordingly, the annual coal washing capacity is planned to reach approximately 1.100.000 tons/year.

Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is investigated. Characterization studies indicated that the coal must be processed after reducing the size to 1.18 mm in order to accomplish substantial yield of the clean coal. A gravity based flowsheet for the -1.18+0.5 mm fraction is developed to generate clean coal at 12% ash with 9.2% overall yield. Mechanical cell flotation circuit for the -0.5+0.15 mm size fraction resulted in additional 3.5% yield at the desired ash level. A flotation circuit for the fine fraction (-0.15 mm) is developed using Jameson Cell only that added further 3.0% yield in the overall mass recovery at 12% ash. Thus, a total of 15.7% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Recycling of some of the intermediate product streams is recommended for continuous operation to enhance the overall yield of the clean coal significantly.

The objective of solid-liquid separation in thickeners in coal preparation plants is to obtain both a clear supernatant liquid with a low turbidity for reuse and a dense slurry. It is important for the smooth operation of the plant to produce good-quality recirculation water. In this study, settling characteristics of coal tailings (d 80 =70 µm) taken from the thickener feed of Derekoy Coal Preparation Plant (Manisa, Turkey) were investigated with the use of anionic polymers. In the tests we determined the effects of the process parameters including polymer type, polymer dosage, temperature, suspension pH, and pulp density on the flocculation of the fine tailings of the coal preparation operation. Minefloc anionic polymer showed a better flocculation performance in comparison with other polymers. An optimum settling rate of 300 mm/min was reached at a dosage of 30 g/t-solids, a pulp density of 5%, pH 7.9, and temperature 25 o C using Minefloc polymer.

Kömürlerin üretildikleri gibi doğrudan kullanımlarını engelleyen en önemli safsızlıklardan biri nemdir. Nem, kömürün kalorifik değerini düşürür, nakliye giderlerini arttırır. Ayrıca, koklaştırma, gazlaştırma ve sıvılaştırma gibi teknolojik işlemlerde ürün kalitesini ve verimliliğini düşürür. Yakma, briketleme, koklaştırma, gazlaştırma, düşük sıcaklık karbonizasyonu ve sıvılaştırma gibi kömür değerlendirme proseslerinin öngördüğü nem sınırlamaları vardır. Kömürün susuzlaştırılması ve filtrasyonu ekonomik açıdan, külünden arındırılması kadar önemli bir işlemdir. Öyle ki, kömürden giderilen %1’lik nem bile kömürün ısıl değerinde 40 ile 60 kalorilik bir artış sağlamaktadır.

Blood flow in the large systemic arteries is modeled using one-dimensional equations derived from the axisymmetric Navier-Stokes equations for flow in compliant and tapering vessels. The arterial tree is truncated after the first few generations of large arteries with the remaining small arteries and arterioles providing outflow boundary conditions for the large arteries. By modeling the small arteries and arterioles as a structured tree, a semi-analytical approach based on a linearized version of the governing equations can be used to derive an expression for the root impedance of the structured tree in the frequency domain. In the time domain, this provides the proper outflow boundary condition. The structured tree is a binary asymmetric tree in which the radii of the daughter vessels are scaled linearly with the radius of the parent vessel. Blood flow and pressure in the large vessels are computed as functions of time and axial distance within each of the arteries. Comparison between the simulations and magnetic resonance measurements in the ascending aorta and nine peripheral locations in one individual shows excellent agreement between the two.

Heat transfer simulation within heating furnaces is of great significance for prediction and control of the performance of furnaces. In this paper, a set of models is proposed to solve heat transfer problems in a loaded furnace. Furthermore, a 2-dimensional algorithm based on a finite difference method is presented. The heat transfer models are integrated with a furnace model to simulate the heating process of workpieces. Temperature variation of the workpiece with time is predicted by the system. An experiment is carried out for validation of the system. The main objective of this work is to evaluate the behavior of a heated enclosure, when variable radiant panels are introduced. Experimental investigation shows that their efficiency depends on their position.

The objective of the book is to demonstrate the up-to-date Polish and intemational experience in the area of thin coal seam mining. The implementation of the plow technology in Poland is done by young engineers for whom the automated extraction system presents itself as a great challenge pinpointing the direction of future developments - a production mining face manned by a skeleton crew, fully utilizing the potential offered by the information technology. They create new ways and means of running the production processes, which are successfully used together with the new generation plows. Successive generations of young mining engineers entering their careers are equipped with a new type of ability and. most of all, awareness which is characterized by a new understanding of reality, in which “real" is what is on the screen. They are the guarantee that this direction of research and the drive towards
minimizing human involvement in the underground production chores will receive inereasing focus and will remain the area of development. The expcriences to-date of three mines (KWK Zofiówka, KWK Jas-Mos, LW Bogdanka S.A.) show that there is a real potcntial for the Polish companies to join in the research aimed at developing new plow installations. This publication is to sum-up the actions-to date taken both in Poland and all over the world in terms of implementing the plow technology in mining.

Seventeen Albanian brown coals were analyzed in detail and their properties were compared on both a national and regional bases. The measurements made were moisture, proximate and ultimate analyses, sulfur forms, bituminous matter, humic acids, and specific energy, plus Gray-King and Free-Swelling Tests. Linear correlations were derived amongst these coal properties on both dry and dry-ash-free bases. The resulting equations would allow the prediction of many coal properties from a limited number of experimental measurements.

The use of low-rank coals as an energy source may cause environmental problems. Washability of a Turkish lignite sample was evaluated by conventional methods with sink-and-float tests and a Reichert spiral. Also, the fine size fractions were cleaned with enhanced gravity separation techniques , a multigravity separator (MGS), and a Falcon concentrator. The as-received lignite sample was sieved into five size fractions (-100 +25.4 mm;-25.4 +12.7 mm;-12.7 +1.2 mm;-1.2 +0.15 mm;-0.15 mm) and the washability characteristics of the first three fractions were separately investigated with sink-float tests. The-1.2 +0.15 mm size fraction was cleaned using a Reichert spiral. Tests with the MGS and the Falcon con-centrator were conducted with a-0.15 mm fine size fraction. Sink-float tests results showed that the tested coal can be classified as difficult-to-clean coal due to the presence of high near-gravity material at lower separation densities than 1.7 g/cm 3. However, the production of cleaner coal was easier at finer size fractions due to further liberation. Enhanced gravity separation techniques presented better results in terms of combustible recoveries. ARTICLE HISTORY

The publication presents the assumptions of the unification process of machines and equipment produced by Jastrzębskie Zakłady Remontowe Sp. z o. o. and operating at the coal mines of the JSW Capital Group. It outlines a solution adopted by JZR Sp. z o. o. addressing this issue. The authors identify the potential benefits of the process to the entire Jastrzębska Spółka Węglowa Capital Group, but they also mention the risks that may arise during its implementation. The publication also presents the first results of the unification, observed on the basis of the unified equipment and machinery of the coal clearance system for transporting people, coal and materials, which has already been put into operation in underground mining excavations. It also includes a chapter devoted to the influence of the unification on the development of “technical thought,” i.e. on the innovativeness of the equipment for transporting people, coal and materials newly produced by Jastrzębskie Zakłady Remontowe Sp. z o. o. which are to be implemented in the near future. New, innovative solutions are presented, which were introduced both in the unified transport devices such as chain and belt conveyors and in devices cooperating with them, i.e. lump breakers, pushing devices and other accessory equipment for the conveyors.

On-line ash monitors have been in use for many years in coal industry. Their operation is usually based on the scattering or the absorption of incident gamma radiation, and the derived ash value is the result of a time-averaged measurement. The natural radiation ...

Heat transfer simulation within heating furnaces is of great significance for prediction and control of the performance of furnaces. In this paper, a set of models is proposed to solve heat transfer problems in a loaded furnace. Furthermore, a 2-dimensional algorithm based on a finite difference method is presented. The heat transfer models are integrated with a furnace model to simulate the heating process of workpieces. Temperature variation of the workpiece with time is predicted by the system. An experiment is carried out for validation of the system. The main objective of this work is to evaluate the behavior of a heated enclosure, when variable radiant panels are introduced. Experimental investigation shows that their efficiency depends on their position.

A variety of low rank coals have been treated by mechanical thermal 10 expression (MTE). Under identical conditions, the percentage water removal decreased in proportion to the water content of the raw coals. Water removal was significant even for a sub-bituminous coal, provided sufficiently stringent conditions were used. The effect of MTE on inorganics removal varied markedly between coals. Large 15 proportions of Na and Cl, but not other inorganics, were typically removed. The amount of organic carbon released to the product water was mainly influenced by processing temperature.

The rapid increase in thermal power generating capacity in Brazil has resulted in the production of huge quantities of brown coal of high ash content. Current estimates indicate that coal ash production in Brazil is likely to reach 4 million tons per year by 2005. In view of the need to burn this type of fuel to the maximum possible

As per the definition in the Słownik Języka Polskiego (“Dictionary of the Polish Language”), unification means the homogenization of something, reducing it to one form or standard, or combining various elements into one whole, integrating, uniting. Can unification also apply to equipment and machinery, what benefits and risks can it bring to the JSW Group, how to make it effective, and is it related to innovation, i.e. technical development of equipment and machinery intended for transporting people, coal and materials? The answers to these questions, developed on the example of the unification process already implemented by Jastrzębskie Zakłady Remontowe Sp. z o. o., constitute the main content of this study. In the years 2015-2018, the JSW Group noted a significant increase in the prices of purchased equipment and machinery for transporting people, coal and materials. Furthermore, the purchasing procedures in force in Poland (Journal of Laws 2019.0.1843 i.e. – Act of 29 January 2004) led to the situation that new equipment was supplied by different manufacturers, and thus differed in design and construction (in some cases even devices purchased from the same manufacturer were of two different models, despite identical requirements included in the ToR of the announced tenders). This led to a situation in which every mine was forced to keep a very extensive and constantly growing stockpile of spare parts acquired with the new equipment. Moreover, in most cases, these
parts could not be used for new equipment, so they constituted the so-called 'frozen capital,' which was, in principle, unrecoverable. However, the diversity of equipment is more than just a problem of parts interchangeability; in 2017, the "Krupiński" JSW mine in Suszec closed down, and its mining staff were deployed in other mines belonging to JSW S.A. Then, it turned out that the diversity of machines is also a problem for the operating team. Workers transferred to different mines had to be retrained in the design and operation  of devices they had not used before, even though they had many years of operating experience on similar equipment. The need for new training and the so-called "learning the machine" did not only concern the relocated employees. The equipment and machinery of the closed “Krupiński” mine, which was still in good technical condition (as well as the stockpile of associated spare parts),
was transferred to other mines of the JSW Group, which in turn made it necessary to train local staff on the machines in question.
Confronting these problems, the JSW Capital Group decided to entrust
Jastrzębskie Zakłady Remontowe Sp. z o. o. with the mission of carrying out the process of unification of all equipment and machinery for transporting people, coal and materials at all mines belonging to the Company, ensuring maximum use of their machinery stocks.

Coal properties are inherently variable even within a single coal seam due to reasons such as coalification history and mining method. Since nonconsistent coal characteristics negatively affect the efficiency and production cost of power plants as well as the profitability of the coal producer, special attention should be paid to control the variability of coal quality. In this paper, variations in coal properties delivered to the Tuncbilek Power Plant have been investigated by means of control charts. The control charts have mostly indicated that the variations in the properties of coal are significantly high. The considerable amount of off-design coal relative to coal contract specifications has been determined. Finally, the revenue of the coal producer has been examined by taking into account the blending operation; the aim of which is to minimize the variance of coal properties.

22 locations in two coal preparation plants in India were evaluated in regard to their vibration characteristics and probable effects on the health of the operators and supervisors of those plants. In some cases notwithstanding the apparently sufficient isolation, vibration was found to be comparatively high. Seven hours as maximum possible exposure duration in any posture in a shift has been adopted in this study. Based on a comparative ranking DMC, vibrating screens, belt conveyors etc, in that order, pose certain health risk to the plant operators in terms of whole body vibration. The hazard potential was found to be related with the make of equipment, nature of installation, operating principles, operating practices, equipment capacity, etc. This exploratory study indicates that epidemiological studies should be conducted in large number of coal preparation plants to ascertain the nature of effects on health due to foot transmitted vibration in tropical climate, though risk assessment models from ISO Standards might not be effectively applied in such cases.

Mayer's potential energy theory is one of the most widely accepted theories describing jigging. While it represented a substantial contribution to jig theory, the potential energy theory can not be applied directly to describe real jigging operations. A modification to that theory has been made recently and is called the dispersion model of jigging. That model, however, is limited to

Low-rank coal (LRC) drying processes are generally categorized by operating temperature, drying environment, and type of feed or product. Within these broad categories, drying processes differ further according to the type of drying equipment and methods of quenching and stabilizing dried products. This paper focuses on the issue of the quality of products produced from a number of LRC drying processes that are commercial or have been demonstrated at a pilot-scale, including low and high temperature evaporative drying and non-evaporative processes, such as hydrothermal drying. Evaporative processes are usually the lowest cost and are preferred when the dried product is used immediately. This avoids the problems of moisture reabsorption, dust generation and spontaneous combustion associated with LRC transportation and long term storage. Hydrothermal drying followed by. low-rank coal-water fuel production is one of the most promising techniques for eliminating stability problems, while producing a value added fuel that will compete in the heavy oil market, not the steam coal market.

Heat transfer simulation within heating furnaces is of great significance for prediction and control of the performance of furnaces. In this paper, a set of models is proposed to solve heat transfer problems in a loaded furnace. Furthermore, a 2-dimensional algorithm based on a finite difference method is presented. The heat transfer models are integrated with a furnace model to simulate the heating process of workpieces. Temperature variation of the workpiece with time is predicted by the system. An experiment is carried out for validation of the system. The main objective of this work is to evaluate the behavior of a heated enclosure, when variable radiant panels are introduced. Experimental investigation shows that their efficiency depends on their position.

Numerical simulation and experimental validations of the growth and departure of multiple merging bubbles and associated heat transfer on a horizontal heated surface during pool boiling under variable gravity conditions have been performed. A finite difference scheme is used to solve the equations governing mass, momentum and energy in the vapor liquid phases. The vapor-liquid interface is captured by level set method, which is modified to include the influence of phase change at the liquid-vapor interface. Water is used as test liquid. The effects of reduced gravity condition and orientation of the bubbles on the bubble diameter, interfacial structure, bubble merger time and departure time as well as local heat fluxes are studied. In the experiments, multiple vapor bubbles are produced on artificial cavities, 2-10 micrometer in diameter range microfabricated on the polished silicon wafer with given spacing. The wafer was heated electrically from the back with miniature strain gage type heating elements in order to control the nucleation superheat. The experiments conducted in earth normal gravity and low gravity environment of KC-135 aircraft are used to validate the numerical simulations. NOMENCLATURE A 0 = dispersion constant, J p c = specific heat at constant pressure, kJ/(kg K) ( ) ε δ φ = smoothed delta function,ϕ = apparent contact angle, deg φ = level set function θ = dimensionless temperature, (T-T s )/(T wall -T s ) κ = thermal conductivity, W/mK µ = viscosity, Pa s ν = kinematic viscosity, m 2 /s ρ = density, kg/m 3 σ = surface tension, N/m Γ = mass flow rate in the micro layer, kg/s s T ∆ = heating wall superheat, K Subscripts , l v = liquid and vapor phase , , r z t = ∂ ∂ / , / , / r y ∂ ∂ ∂ ∂t , s wall = saturation, wall int = interface ∞ = infinite y z z z z z z z z z z

... 19392690801925813 Zhanyou Huang a , Manoj Mohanty b * , Hasan Sevim c , Ajay Mahajan b & ... AM Mahajan and MK Mohanty , Performance Optimization of a Coal Preparation Plant Using ... The authors also greatly appreciate the guidance provided by Dr. Subhash Bhagwat ...