scholarly journals Characterization of Cleaning Potential of Khokhar-Bala, Punjab (Pakistan) Coal and Simulation-Based Study for Identification of Best Strategy for its Cleaning

Author(s):  
Muhammad Shahzad ◽  
Syed Mahmood Arshad ◽  
Zulfiqar Ali ◽  
Rana Ahmad Ali ◽  
Hamza Shabeer

This study involves the characterization of Khokhar-Bala coal of Punjab (Pakistan) coal field to establish its particle distribution data for size, density and floatability through sizing, float-sink tests and release analysis. Khokhar Bala coal contains high amounts of unwanted impurities like ash (35.22%) and sulphur (8.38%). Over 93% of its mass consists of +1.00 mm particles, when run-of-mine coal is crushed to 38 mm. Washability curves, degrees of washing and the S-values show that the coarser fractions (-38+25 mm; -25+13.33 mm; -13.33+3.35 mm) are extremely difficult to clean, whereas the cleaning potential is high for size fractions -3.35+1.00 mm (moderately difficult) and -1.00+0.15 mm (relatively easy). Modelling and simulation of several processing configurations indicate that at 16% target ash content, dense medium cyclone treating 38 x 1 mm coal particles will provide the maximum clean yield of 37.39% with sulphur content of 4.80%.    

2016 ◽  
Vol 9 (2) ◽  
pp. 58-70 ◽  
Author(s):  
Veera AK Aketi ◽  
TR Vakamalla ◽  
M Narasimha ◽  
GE Sreedhar ◽  
R Shivakumar ◽  
...  

In this paper, the effect of near gravity material at desired separation density during the coal washing is studied. It is believed that the Dense Medium Separation of coal particles in the presence of high percentage of near gravity material, results in a significant misplacement of coal particles to wrong products. However the performance of dense medium cyclone does not merely depend on the total amount of near gravity materials but also on their distribution as well as on their quality. This paper deals with numerical simulation of magnetite medium segregation and coal partitioning handled in a 350 mm dense medium cyclone. Volume of Fluid coupled with Reynolds Stress Model is used to resolve the two-phase air-core and turbulence. Algebraic Slip mixture multiphase model with the granular options are considered to predict magnetite medium segregation. Medium segregation results are validated against Gamma Ray Tomography measurements. Further, Discrete Phase Model is used to track the coal particles. Residence Time Distribution of different size and density coal particles are also estimated using Discrete Phase Model. Additionally, Algebraic Slip mixture model is also utilised to simulate magnetite and coal particle segregation at different near gravity material proportions. Discrepancies in the coal particle behaviour at different near gravity material content are explained using locus of zero vertical velocities, mixture density, coal volume fractions.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Y. K. Xia

Extensive progress has been made in using CFD tool in the simulation of multiphase flows in some gravity concentrators. Several case studies for calculation of multiphase flows by different numerical models in spiral, dense medium cyclone, water only cyclones, hindered-settling bed separator, heavy medium vessel and jig are reviewed. The Euler-Lagrange approach in calculation of the particle movement and particle-liquid coupling effect are also discussed. The limitation of Euler-Euler models in the treatment of the particles with a size distribution, and disadvantages of discrete element method (DEM) in description of the jigging processes will be presented. The successful two-dimensional simulation of the hindered-settling bed separator, heavy medium vessel and jig by Euler-Lagrange approach is also addressed.


1985 ◽  
Vol 5 (7) ◽  
pp. 609-614 ◽  
Author(s):  
A. Lodola

The uptake and intracellular distribution of haem by isolated rat hepatocyte suspensions was studied. An increase in cell haem content occurred after a challenge with 5, 10 or 20 μM haem, supplied as methaemalbumin. The rate of haem uptake was temperature dependent; no non-specific binding occurred. Intracellular haem distribution data are consistent with a rapid association of haem with the endoplasmic reticulum fraction prior to its accumulation in the cytosol and at the mitochondrion.


2018 ◽  
Vol 1 (1) ◽  
pp. 264-270
Author(s):  
Hady Wiraputra ◽  
Marline Nainggolan ◽  
Panal Sitorus

Tanaman buni (Antidesma bunius (L.) Spreng.) secara tradisional telah digunakan untuk hipertensi, takikardia, anemia, sifilis, antikanker, antioksidan, sumber pewarna alami dan antidiabetes. Saponin merupakan senyawa fitokimia yang mempunyai kemampuan membentuk busa dan mengandung aglikon polisiklik yang berikatan dengan satu atau lebih gula. Penelitian ini bertujuan untuk melakukan karakterisasi senyawa saponin hasil isolasi dari daun buni dengan spektrofotometer ultraviolet dan inframerah. Simplisia daun buni dilakukan karakterisasi kemudian diekstraksi dengan cara maserasi bertingkat menggunakan pelarut n-heksana dan etanol 80%. Selanjutnya ekstrak etanol dihidrolisis dengan HCl 2N kemudian difraksi dengan pelarut kloroform. Isolasi dilakukan terhadap fraksi kloroform dengan cara kromatografi lapis tipis preparatif menggunakan fase diam silika gel GF254 dan fase gerak yang sesuai. Isolat yang diperoleh diuji kemurnian dengan KLT 2 arah dan dikarakterisasi menggunakan spektrofotometer ultraviolet dan inframerah. Hasil pemeriksaan karakterisasi simplisia diperoleh kadar air 7,32%, kadar sari larut dalam etanol 52,70%, kadar sari larut dalam air 23,25%, kadar abu total 6,86% dan kadar abu tidak larut dalam asam 0,94%. Pemisahan fraksi kloroform dengan KLT menggunakan fase gerak n-heksana-etilasetat perbandingan 5:5 diperoleh noda 13 dan hasil KLT preparatif diperoleh 2 isolat murni yaitu isolat 1 (ungu merah) dengan Rf 0,92 dan isolat 2 (biru) dengan Rf 0,78. Hasil karakterisasi isolat 1 diperoleh panjang gelombang maksimum pada 208 nm dan dijumpai adanya gugus hidroksil, gugus -CH alifatis, ikatan C=C, gugus –CH2, gugus –CH3, dan gugus C-O. Hasil karakterisasi isolat 2 diperoleh panjang gelombang maksimum pada 204 nm dan adanya gugus hidroksil, gugus -CH alifatis, gugus –CH2, gugus –CH3, dan gugus C-O. Buni (Antidesmabunius (L.) Spreng.) has been traditionally used for the treatment of hypertension, tachycardia, anemia, syphilis, and used asanti-cancer, anti-oxidant, natural dye, and anti-diabetic. Saponin is a phytochemical compound which has capability in forming foam and contains polycyclic aglycone that binds with one or more glucose. This research aimed to conduct the characterization of saponin compound from buni leaves with ultraviolet spectrophotometer and infrared. Buni leaves simplicia was characterizedand extracted using sequential maceration method with n-hexane and 80% ethanol. The ethanol extract was hydrolyzed with HCl 2N and fractionized using chloroform solvent. Isolation of chloroform fraction was done using preparative thin-layer chromatography using silent phase of silica gel GF 254 and suitable mobile phase. Isolates obtained was taken into purity test with two dimensions thin-layer chromatography and characterized using ultraviolet spectrophotometer and infrared. The characterized simplicia resulted with 7.32% of water content, 52.70% of dissolved content in ethanol, 23.25% of dissolvedcontent in water, 6.86% of total ash content, and 0.94% of undissolved ash content in acid. Fractinationof chloroform fraction with thin-layer chromatography using mobile phase ofn-hexane-ethyl acetate with 5:5 ration resulted with 13 spotsand the result of the preparative thin-layer chromatography resulted 2 pure isolates which are isolate 1 (purple-red) with Rf 0.92 and isolate 2 (blue) with Rf 0.78. The characterization of isolate 1 resulted that the maximum wave lengthwas 208 nm with hydroxyl group, –CH aliphatic group, C=C bond, –CH2 group, –CH3 group, and C–O group. The characterization of isolate 2 resulted that the maximum wave lengthwas204 nm with hydroxyl group, –CH aliphatic group, –CH2 group, –CH3 group, and C–O group.


2020 ◽  
Vol 24 (3) ◽  
pp. 112-118
Author(s):  
Dace Âriņa ◽  
Rūta Bendere ◽  
Gintaras Denafas ◽  
Jānis Kalnačs ◽  
Mait Kriipsalu

AbstractThe authors determined the morphological composition of refuse derived fuel (RDF) produced in Latvia and Lithuania by manually sorting. The parameters of RDF (moisture, net calorific value, ash content, carbon, nitrogen, hydrogen, sulphur, chlorine, metals) was determined using the EN standards. Comparing obtained results with data from literature, authors have found that the content of plastic is higher but paper and cardboard is lower than typical values. Results also show that the mean parameters for RDF can be classified with the class codes: Net heating value (3); chlorine (3); mercury (1), and responds to limits stated for 3rd class of solid recovered fuel. It is recommended to separate biological waste at source to lower moisture and ash content and increase heating value for potential fuel production from waste.


2015 ◽  
Vol 23 (3) ◽  
pp. 1117-1122 ◽  
Author(s):  
Lijun Zhang ◽  
Xiaohua Xia ◽  
Jiangfeng Zhang

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