ABSTRACT The following performance between solid particle and liquid phases inside a hydrocyclone remains unclear. The purpose of this paper was to study the following pattern of solid-liquid phases in a hydrocyclone, and to explore the influencing factors affecting solid-liquid followability. Numerical simulation of the effects of seven particle sizes, two particle concentrations and two feed rates

ABSTRACT Dewatering is considered as extremely significant and primary step to enhance the quality of lignite. A great number of research focus on conventional fluidized-bed drying technology or dynamics. In this paper, the microwave deep drying kinetics of Zhaotong lignite under different power levels and with different sample thicknesses were investigated. The drying kinetics of microwave deep drying

ABSTRACT In order to solve the problems of insufficient filtration performance of bag dust collector in coal mine and improper selection of filter materials, the performance parameters of seven kinds of filter materials were compared and analyzed. The results showed that with the increase of filtration time, the resistance of different filter materials showed an upward trend, the resistance of ordinary

ABSTRACT A new theoretical formula can be used to calculate superficial velocity for particle separation with a critical condition, and it is based on the size, density, terminal velocity, Reynold number of the particle, and equipment parameters. In a continuous system, a series of fractionation experiments were conducted to quantify the separation performance ranges for various operational factors

ABSTRACT In the present study, the flocculation of multi-component coal waste slurry was investigated using an eco-friendly hybrid polymer naturally derived. The three significant operational parameters of the flocculation process, polymer dosage, suspension pH, and mixing time, were varied and the results were evaluated with the Central Composite Rotatable Design. In order to the flocculation process

ABSTRACT Lignite is easily oxidized, and spontaneous combustion occurs during its storage, which greatly reduces its calorific value and affects its quality and economic benefits. The surface properties of the oxidized lignite including pore structure and oxygen-containing functional groups were investigated by N2 adsorption/desorption isotherms and Fourier transform infrared spectroscopy. The adsorption

ABSTRACT The aim of this study is to find a biobinder for the production of waterproof or at least water-resistant coal briquettes from the Slater coal slurry of South Africa. From an economic point of view, molasses and crude glycerol were used as raw materials for the production of binders. To obtain comparable results, the binders were prepared from either pure or crude glycerol. The results indicated

ABSTRACT In the process of coal formation at deep coal seam, the coal quality changes by geological environment. Under the influence of high-temperature and surrounding heat storage conditions, the combined capacity of coal and oxygen is enhanced, and the risk of coal spontaneous combustion is enhanced. Based on the spontaneous combustion law of coal in deep high-temperature and thermal environment

ABSTRACT Gasification is an efficient and environmentally friendly treatment process for petroleum coke. But the rheology and stability of petroleum coke-water slurries (PWS) do not meet the feeding requirements of gasification. This study blends Hami coal (HM) with two petroleum cokes (Lianyungang (LYG) and Lanqiao (LQ)) to prepare high quality slurries. The results indicate that the properties of

ABSTRACT In reuse of process water in flotation plants, the inability to measure residual frother concentrations in both flotation and plant water circuits in real time has created challenges for flotation process control. We previously developed a simple and fast method to measure frother concentration based on the guest–host interactions between frother molecules and specially formulated liquid comprising

ABSTRACT In this research work, thar coal was treated with NaOH solution in dissolved oxygen with different reaction parameters in an isothermal reactor. All three types of sulfur were removed from coal through oxidative alkali leaching under pressure. About 90% pyretic sulfur, 78% organic sulfur and 50% sulfate sulfur were removed, and more than 82% of total sulfur removal was achieved. Effects of

ABSTRACT Spontaneous combustion of coal in stockpiles of power plants has a significant problem worldwide which leads to several health hazards, environmental pollution and coal loss. Spontaneous combustion coal stockpiles depend on both endogenous (coal characteristics) and exogenous parameters (stockpile geometry, wind speed, wind direction, local temperature). This paper describes the laboratory

ABSTRACT Crushing mechanism plays a vital role in liberation of coal macerals (organic constituents), which aid in coke making. Due to the use of impact mills, vitrinite maceral grains shatter and participation in coke making is reduced. To address this issue, a new crushing machine based on a shear fracture mechanism has been developed and termed as coal shear crusher (CSC). It is shown that by using

ABSTRACT Zeta potential of coal particles and kinetics of flotation along with the maximum recovery after a long time of fractionated flotation of naturally hydrophobic coals, both as a function of pH, were investigated. Empirical relations between the 1st order rate constant of flotation and zeta potential as well as the maximum recovery and zeta potential were established. Since fractionated flotation

ABSTRACT To enhance the combustion efficiency of high moist coal, it is important to reduce its moisture contents. For reduction of moisture contents, the selection of efficient and low-cost drying technique based on the coal characteristics is helpful to convert the high moist coal to good quality fuel. A total of 18 Thar coal (Pakistan) samples were crushed and sieved at following size fractions

ABSTRACT Although column flotation cells have been extensively studied in the literature, the hydrodynamic impact of orifice properties has not been adequately addressed yet. This paper initially investigates the effect of sparger orifice diameter on hydrodynamic behavior of coal particles in a pilot-scale column flotation. The metallurgical responses (i.e., ash, yield and recovery contents) were evaluated

ABSTRACT The Hardgrove Grindability Index (HGI) is a measure of coal’s resistance to crushing. HGI is influenced by many factors due to the complex structure of coal. This study examines the effect of the proximate and ultimate analysis and maceral content on HGI, based on 329 samples of Polish coals. In this study, a machine learning technique XGBoost (Extreme gradient boosting regressor) was used

ABSTRACT Various studies have reported that electrolytes present in the plant’s process water influence the coal flotation performance. However, coal fines, which are fed into the flotation circuit are from different coal seams, and their surface properties usually vary considerably. In this study, flotation experiments were conducted using coal fines from three different coal seams of the West Bokaro

ABSTRACT Implementing the planned execution of experiments will optimize the resources and time of a newly developed process or equipment. In the present work, the screening machine is newly developed equipment designed for the separation of coal. The present work was carried out to evaluate the performance of separation efficiency of the screening machine using generalized and forward selection fractional

ABSTRACT Since coal washeries generate huge quantities of high-ash rejects as waste, effective utilization of coal rejects help in sustainable coal preparation. Out of different coal rejects, tailings from froth-flotation process can be a potential material for the extraction of clean coal due to its fine size, availability in the slurry form, presence of good carbon values, and better liberation properties

ABSTRACT Coal is a valuable source for power energy as well as for metal contents within it. Coal and its by-product are considered a promising resource for the critical elements and rare earth elements (REEs). The study of REEs in coal is in its infancy. This paper focuses on REEs’ occurrence, qualitative, and quantitative in coal and its by-products (shale coal, shale coal ash, and coal ash) of Sohagpur

ABSTRACT In the present work, optimization of the newly developed vibrating screen’s operational parameters was carried out to obtain a high response parameter. The operational parameters considered in the present work were moisture content, angle, and frequency. The Taguchi L27 design technique was used to optimize three different operational parameters to obtain high screening efficiency of coal

ABSTRACT This work studies the in-situ conversion technology of solid fossil fuels to liquid and gaseous products. The investigated approach consists of the pyrolysis of solid fuel within the temperature range of 500–700°C. Heating occurs due to the flow of current through the electrothermal breakdown channel. The electrical contact with the coal is implemented via electrodes located in the wells.

ABSTRACT A rectangular inlet generally exceeds a circular inlet in separation performance. However, there still lacks detailed information that can appropriately determine the height-to-width ratio of the rectangular inlet. For this reason, this study investigated the effect of the height-to-width ratio of the rectangular inlet on the separation performance of hydrocyclone with a diameter of 75 mm

ABSTRACT Phosphorus is critical for the strength of metals; however, in excess it makes the metal product fragile. This leads to quality complaints and financial losses. Phosphorus is finely disseminated in coal and forms part of the coal structure. Despite the use of a coal facility at Morupule, the final product surpasses the maximum limit of 0.02% phosphorus. Reduction of the phosphorus by convectional

ABSTRACT In this study, the rotary triboelectrification separation technology is applied to the separation of macerals for low rank coal, which has not been studied by previous researchers. The effects of air humidity and temperature on permittivity and specific-charge were tested to ensure that vitrinite and inertinite were effectively separated under obvious electrical differences. The best separation

ABSTRACT In this study, the deashing of Sivas-Kangal (Turkey) lignite was carried out under different conditions. Solids ratio (20%, 30%, 40% and 50% by weight), centrifugal force (20, 100, 176 and 300 G), feed rate (0.5, 1.0, 1.5 and 2.0 L/min) and particle size (−300, −212, −150 and −75 µm) were selected as experimental parameters. Taguchi experimental design was used to optimize Falcon parameters

ABSTRACT Flow field characteristics of Falcon separator are studied by CFD simulation based on Euler-Euler model as multiphase flow model and Reynolds stress model as turbulence model, including particle movement state in delamination area and separation area, three phase (Tangential, radial and axial directions) velocity distribution and turbulence field distribution. Simulation results show that

ABSTRACT The high-ash low-grade coals of Indian origin are relatively more challenging to demineralize due to their unfavorable hydrophilic surface chemistry. Herein, we report castor oil as a potential bridging liquid, which efficiently agglomerated high-ash low-grade coals by 55–60% at lower concentration (10 wt%) compared to literature (20–25 wt%), without inclusion of surfactants. A blend of castor

ABSTRACT The size reduction is a mandatory step in oil shale processing. In this study, the sensitivity of oil shale and its organic matters to the applied load in grinding was tested in a ball mill not only by using the different number of grinding media balls as an effective load but also by using balls made of two materials, namely, steel and ceramic. The ground product was characterized in terms

ABSTRACT The misplacement of coarse particles in overflow and fine particles in underflow are common problems in hydrocyclone separation. This study aimed to propose a hydrocyclone with a spiral inlet structure to improve the separation performance, and the design method of the spiral inlet is given. Based on verifying the accuracy of the VOF model and the Mixture model, the flow field characteristics

ABSTRACT In order to investigate P-containing flame retardant on coal spontaneous combustion, trisodium phosphate, sodium hexametaphosphate, and ammonium polyphosphate were selected. Raw coal and inhibitor solution (10 wt%) were mixed at weight ratio 4:1. Coal (raw coal, inhibited coals) oxidation reaction was measured by own designed temperature-programming device. Simultaneous TG-DSC was carried

ABSTRACT Ammonium polyphosphate (APP) is a type of fire-fighting material that has excellent performance; however, it also has the disadvantage of facile deliquescence. Microcapsule technology is therefore employed in this study to use melamine resin as encasing material in the preparation of melamine–formaldehyde resin-microencapsulated APP. The performance of prepared microcapsules is characterized

ABSTRACT Sulfur dioxide (SO2) and nitrogen oxides (NOx) in flue gas are a hazardous atmospheric pollutant associated with coal combustion and non-ferrous metal production. Here we report that laboratory pilot unit for scrubbing of industrial flue gas containing 80 ± 2 ppm SO2 followed by melt regeneration with either CO or natural gas, verified that only 1.5–2.0 ppm SO2 remained in the flue gas. The

ABSTRACT In coal beneficiation, ash content is the main focus area as it plays a vital role in controlling the yield and quality of the washed clean coal. Indian sub-bituminous and bituminous coals are of low-grade with intrinsically distributed ash-bearing minerals, which makes it difficult to segregate the low ash coal. Different stages of crushing and grinding techniques have been used to produce

ABSTRACT In this study, we investigated the effect of the scrubbing medium’s particle size distribution on the scrubbing flotation performance of microcrystalline graphite. A simplex lattice mixture design approach using Design-Expert software was employed for proportioning testing of the scrubbing media. Three different sizes of scrubbing medium (A: 1 mm, B: 2 mm, and C: 3 mm) were mixed to obtain

ABSTRACT Determining and continuously monitoring the quality parameters (proximate and calorific value analysis) of coal is crucial for mining, power generation, and trading purposes. Although proximate and calorific analyses are compulsory for monitoring, on-line methods continuously determine these parameters using expensive, detached equipment. Few studies predict the coal quality parameters using

ABSTRACT In this paper, the enhanced gravity separation of maceral components was studied based on the characteristics of maceral components for low-rank coal from Shendong. Vitrinite and ash content were only 48.42 and 8.77%, respectively. Rod mill grinding showed that the optimal grinding time was 10 min based on the vitrinite content and vitrinite recovery which reached maximum 81.34 and 80.85%

ABSTRACT To detect coal content in gangue, a novel approach based on image analysis and particle swarm optimization–support vector machine (PSO-SVM) was presented. First, 15 features that included four sizes and 11 density parameters were extracted from coal and gangue regions of sample pictures, respectively. For the size parameters, the values of each feature are summed up by class, while for the

ABSTRACT Coal is one of the chief energy sources having significant applications in the iron and steel industry. This research investigates the screening efficiency of coal of different size range. The experiments on the screening of coal with different size range in the screening machine were carried out using different mesh sizes. The screening efficiency for different screen angles and frequency

ABSTRACT Lignite briquetting provided an effective method for the utilization of lignite powder. Based on the briquetting conditions of lignite, two kinds of binders (sodium humate and polyvinyl alcohol) were selected for the present study. The compressive and drop strengths of briquette were used as indicators to design an orthogonal experiment to examine the effect of composite binders. From the

ABSTRACT Spontaneous combustion (SPONCOM) is a complex physical and chemical process involving several known and unknown variables which necessitates experimental detection methods and prediction hypotheses to minimize significant environmental pollution. Coal SPONCOM results in severe environmental pollution, safety threats, and substantial economic losses. This phenomenon has not only resulted into

ABSTRACT Sorting coal using x-ray transmission sensors has been explored since 1972 by Jenkinson et al. Coal sortability is assessed using washability derived from dual-energy X-Ray transmission (DE-XRT) system. Coal sorting is considered to be dry separation of coal that can be carried out before coal is send to the processing plant. It can act as deshaling/destoning process or it can also be used

ABSTRACT A kukersite oil shale sample from Estonia was pyrolyzed using a Fischer assay method under N2, N2/steam, CO2 and CO2/steam environments. The thermal behavior of the oil shale sample was also studied using TGA and DSC with similar conditions. Also, several properties of produced oils were measured and FTIR analysis was carried out to compare the molecular structure of the derived oils. The

ABSTRACT Coke reactivity index and coke strength after reaction traditionally evaluated by reacting coke with carbon dioxide in standard condition. Several testing standard/methods viz., American society for testing and materials, Japan Industrial Standard, Bureau of Indian Standards, and International Organization Standard exists, which are used worldwide to measure the hot strength of metallurgical

ABSTRACT The liberation characteristics of long flame coal from the Chinese Shenhua were studied by comparison of ball grinding and rod grinding. First, the effects of grinding time on maceral liberation under the different particle size range, including vitrinite content (VC), vitrinite liberation degree (VLD) and vitrinite monomer content (VMC) were researched. Then, the influence of different grinding

ABSTRACT Coke producers are facing a tough challenge to produce good quality metallurgical coke at reasonable price due to decreasing availability and increasing cost of good quality hard coking coal.The use of alternative carbon source like non-coking bituminous coal, heat altered coking coal (Jhama), petcoke can be a way to address the problem. In this article, the effect of preheating and stamp

ABSTRACT The effect of cofiring elaeis guineensis residues with coal pellets for power generation was investigated. Samples of elaeis guineensis residues (palm kernel shell (PKS), palm fiber (PF) and empty fruit bunch (EFB)), and coal were collected and pulverized. The pellets were thereafter produced mechanically, using an optimized mixing ratio of 80:20. Coal palm kernel shell (CPKS), coal palm fiber

ABSTRACT In this paper, coal screening in vibrating screen was carried out with the size ranges of −6 mm + 4 mm, −4 mm + 2 mm, and −2 mm + 0.5 mm. The vibrating screen was newly designed with flexibility in angle and frequency. The vibrating screen experimentation was carried out by varying screen mesh, angle, and screen frequency. During the screening, the angle was kept constant, and frequency was

ABSTRACT A dynamic floc measurement system was developed to analyze flocs during sedimentation and automatically extract floc characteristics without damaging them. An optimized algorithm was proposed to remove fuzzy flocs, and visual inspection verified that this algorithm achieved satisfactory separation performance between well-defined and fuzzy flocs. This program was used to study the development

ABSTRACT In order to find a green and effective chemical desulfurization method, the photocatalytic technology and oxidative desulfurization were combined to minimize the sulfur content in coals. In this paper, 30% H2O2 was mixed with raw coal, demineralized coal, and removal pyrite coal at a ratio of 5:1 (ml: g), the oxidative desulfurization reaction was carried out with visible light irradiation

ABSTRACT A huge amount of coke breeze with its particles size smaller than 10 mm, is generated and accumulated during coke production, transportation and crushing process, which cannot be effectively used, causing wasting of coke resource. Cold briquetting of coke breeze was investigated in this study to produce formed coke with certain size and strength to satisfy the demands of metallurgical industry

ABSTRACT The effect mechanism of mixing ratio on the adsorption behavior of low-rank coal surface using mixed collectors has not been systematically studied. In this study, dodecane (D) and n-valeric acid (N) were mixed into different collectors in different ratios, and their adsorption mechanism on the surface of LRC was studied by experiment and simulation calculation. The flotation results indicated

ABSTRACT Bubble–particle interactions are crucial in the flotation process, and the influence of adsorbed chemicals on bubble-surface collisions/attachment is important to fully understand the role of mixed collector in low-rank coal (LRC) flotation. In this paper, the process of rising bubble attachment to LRC surface in the presence of adsorbed dodecane (D)-oleic acid (OA) collector mixture was studied

ABSTRACT Image-based separation of coal and gangue is susceptible to the external environment. This paper studies the effects of illuminance and external moisture on grayscale and texture features of coal and gangue images. We first build an image acquisition system and construct an image dataset of coals and gangues under different illuminance and external moisture. Secondly, we extract four grayscale

ABSTRACT The correlation between froth properties and the quality of the froth product is the key to predict flotation performance and improve the automatic control of flotation. It is known that froth gray value increases with the clean coal ash content and is often used in the prediction of coal flotation performance. But the accuracy of ash content prediction is usually unsatisfactory because the

Abstract By thermogravimetry (TG) experiments, evolution behaviors and properties of thermal oxidation processes at low temperature (< 230.0 °C) of a bituminous coal with five moisture contents were investigated. A novel Acceleration Temperature Point Method (ATPM), defined as the transition point from low-temperature oxidation to rapid self-sustained heating-up period, was proposed to determine the

ABSTRACT High-rank coals are generally more floatable than low rank or oxidized coals due to their higher hydrophobicity. Surface oxidation of coals due to the exposure to atmospheric oxygen renders the surface some hydrophilic character. As a result, the low rank or oxidized coals do not effectively attach to air bubbles and result in lower flotation yields. Nonpolar collectors like diesel and other

ABSTRACT Coal fires around the world are challenging and recurrent problems anywhere coal is being mined, processed, stored and transported. Coal spontaneous combustion (SPONCOM) is the reason behind most of these fires. Therefore, when taking preventive actions against the risk of coal fires, it is essential to evaluate their degree of liability to avoid the loss of valuable and unrenewable resources

ABSTRACT The present paper outlines the work done on beneficiation of low-rank-oxidized coal fines by flotation using a biodegradable oil (iluppai or Mahua) to reduce the ash content. Prior to flotation, characterization of the coal and the reagents were done by FTIR and SEM-EDS analysis to identify the functional groups. Batch tests were performed with biodegradable and conventional oil (Diesel) as