Academic literature on the topic 'Coal Extraction (Chemistry)'

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Journal articles on the topic "Coal Extraction (Chemistry)"

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Kozłowski, Mieczysław, Helena Wachowska, and Jan Yperman. "Composition of extraction products from alkylated high-sulphur coals." Open Chemistry 1, no. 4 (December 1, 2003): 366–86. http://dx.doi.org/10.2478/bf02475223.

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AbstractProducts of reductive and non-reductive methylation of two high-sulphur coals (Mequinenza and Illinois No. 6) have been extracted by dichloromethane. It has been established that the efficiency of the transformation of coal to the products soluble in CH2Cl2 is higher for coals subjected to non-reductive methylation by the Liotta method than for those after reduction in the potassium/liquid ammonia system. The extracts and the extraction residues were subjected to elemental analysis, IR spectroscopy, and AP-TPR (Atmospheric Pressure-Temperature Programmed Reduction) measurements. It has been shown that the main species undergoing extraction by CH2Cl2 are aliphatic compounds or aromatic structures of low degree of condensation. The effect of the extraction on the sulphur groups in coal has been discussed.
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Tasic, Aleksandra, Ivana Sredovic-Ignjatovic, Ljubisa Ignjatovic, Danijel Djuranovic, and Malisa Antic. "Aqueous extraction of anions from coal and fly ash followed by ion-chromatographic determination." Journal of the Serbian Chemical Society 81, no. 12 (2016): 1441–53. http://dx.doi.org/10.2298/jsc160223086t.

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Three different techniques were applied for the aqueous extraction of anions from coal and fly ash: rotary mixer- and ultrasonic-assisted extraction with different duration time, and microwave-assisted extraction at different temperatures. Validation showed that the ion-chromatographic method was suitable for the analysis of anions in coal and fly ash extracts. The variations in the amounts of anions using different extraction times during rotary-assisted extraction were minimal for all investigated anions. The efficiency of ultrasound-assisted extraction of anions from coal depended on the sonication time and was highest at 30 min. The ultrasound-assisted extraction was less efficient for the extraction of anions from fly ash than rotary-assisted extraction. Increase of temperature in the microwave-assisted extraction had a positive effect on the amounts of all anions extracted from coal and sulphate from fly ash, while the amounts of fluoride and chloride in fly ash extracts decreased. The microwave-assisted extraction of coal at 150?C was compared with standard ASTM methods, and results were in good agreement only for chloride. Changes in the pH value and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of coal particles in contact with water and different processes that occur under environmental conditions.
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Antonovits, Ábel Dániel, and József Molnár. "3D modelling of coal seams for optimization of extraction." MATEC Web of Conferences 342 (2021): 02008. http://dx.doi.org/10.1051/matecconf/202134202008.

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Underground coal mining was finished in the north-eastern region of Hungary after its operation of more than two centuries, as a result of economic, technical, environmental and political reasons. A fairly significant part of the reserve is still available to extract. With a different perspective of coal mining, considering different ways of utilization (such as coal chemistry, etc.) the extraction of the material can still be cost effective. In the past few years, several studies were conducted regarding the possible utilization of the available reserve. The properties of the coal are highly mutable, therefore, comprehensive knowledge about the geology is indispensable. Two and three-dimensional modelling of the coal seam is discussed in this paper, with the optimal coal face height, and the expected quality of mining products taken into consideration. Applying the method presented, the production can fulfil the desired properties, regarding to the utilization of the coal.
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Cooke, Norman E., O. Maynard Fuller, and Rajendra P. Gaikwad. "Ultrasonic extraction of coal." Fuel 68, no. 10 (October 1989): 1227–33. http://dx.doi.org/10.1016/0016-2361(89)90234-2.

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Nishioka, Masaharu. "Multistep extraction of coal." Fuel 70, no. 12 (December 1991): 1413–19. http://dx.doi.org/10.1016/0016-2361(91)90007-w.

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Pietrzak, Robert, Helena Wachowska, and Piotr Nowicki. "The effect of flame coal oxidation on the solid and soluble products of its extraction." Open Chemistry 3, no. 4 (December 1, 2005): 852–65. http://dx.doi.org/10.2478/bf02475208.

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AbstractSolid and soluble products of THF and CH2Cl2 extraction of flame coal oxidised by four different oxidising agents (peroxyacetic acid (PAA), 5% HNO3, O2/Na2CO3, air/125 °C) were studied by elemental analysis and FTIR. The extraction yield with THF was much higher than that with CH2Cl2 for all samples. The greatest changes in elemental composition were in the extracts from coal oxidised by nitric acid. The sulphur content was lowest in extracts from coal oxidised with 5% HNO3 and PAA. FTIR confirmed that coal treatment with nitric acid incorporates nitrogen into the coal structure.
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Smith, Aidan M., and Andrew B. Ross. "The Influence of Residence Time during Hydrothermal Carbonisation of Miscanthus on Bio-Coal Combustion Chemistry." Energies 12, no. 3 (February 7, 2019): 523. http://dx.doi.org/10.3390/en12030523.

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Miscanthus was treated by hydrothermal carbonisation in a 2-L batch reactor at 200 °C and 250 °C with residence times ranging between 0 and 24 h to understand the impact of residence time has on the resulting bio-coal combustion chemistry. Increasing the residence time results in dehydration of the bio-coal and increased repolymerisation; however, temperature has the greatest influence on bio-coal properties. After 24 h at 200 °C, bio-coal has similar properties to that of the 250 °C + 0 h bio-coal. After 1 h at 250 °C, the cellulose present in the raw biomass appears to be largely removed. The removal of cellulose and the associated dehydration and repolymerisation results in bio-coal having a ‘coal like’ combustion profile, which exhibits a decreasing reactivity with increasing residence time. At 200 °C + 0 h, 75% of the alkali metal is removed, increasing to 86% with increasing residence time. Further extraction is seen at 250 °C. Phosphorus and sulphur appear to undergo substantial extraction at 200 °C + 0 h but then are reincorporated with increasing residence time. The calcium content increases in the bio-coal with increasing residence time at 200 °C but then reduces after 1 h at 250 °C. Increasing temperature and residence time has been shown to decrease the fuels’ fouling and slagging propensity.
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Yao, Jian, Huaijun Ji, Huazhang Lu, and Tongtong Gao. "Effect of Tetrahydrofuran Extraction on Surface Functional Groups of Coking Coal and Its Wettability." Journal of Analytical Methods in Chemistry 2019 (June 26, 2019): 1–8. http://dx.doi.org/10.1155/2019/1285462.

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Coking coal was extracted with tetrahydrofuran solvent using ultrasonic and microwave-assisted method at 50°C and atmospheric pressure. Wettability of raw coal and its residue (residual coal) was tested with capillary penetration method. The raw and residual coals were studied by Fourier transform infrared spectroscopy (FTIR) with curve-fitting analysis. The variation of main surface functional groups of coking coal before and after extraction and its effect on wettability were analyzed. The results were obtained as the following: after extraction with tetrahydrofuran, hydroxyl, ether oxygen, and carbonyl in the coal structure were dissolved, the content of hydrophilic functional groups reduced, and then the hydrophobicity of coal enhanced. At the same time, part of aliphatic hydrocarbon dissolved, the length of aliphatic chains (I2) decreased from 3.961 of raw coal to 3.636 of residual coal, the length of aliphatic chains became shorter, aliphatic CH2 side-chains decreased and aliphatic CH3 side-chains increased, and hydrophobic functional groups content increased. In the aromatic structure, four hydrogens per ring increased and two, three, and five hydrogens per ring decreased. Reduction of substitution functional groups and aliphatic hydrocarbon decreased with the side-chains breakage produce more active sites, which increases the degree of condensation of the aromatic ring (I3). The combined action of the decrease of the hydrophilic functional groups and the increase of the hydrophobic functional groups made the wettability of the coking coal become weak.
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Xie, Heng-Shen, Zhi-Min Zong, Yu-Gao Wang, Pei-Zhi Zhao, Shi-Hua Zhang, Jun-Qiang Wang, Hong Fu, Shuang-Hua Liang, Ling Su, and Xian-Yong Wei. "Conversion of Organic Matter in Coal by Photocatalytic Oxidation with H2O2 over SFC/TiO2 in Isolated Oxygen System." Journal of Chemistry 2019 (October 24, 2019): 1–12. http://dx.doi.org/10.1155/2019/1768351.

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Shenfu bituminous coal (SFBC), Geting coal (GTC), Shengli lignite (SLL), and Holingola coal (HLGLC) were oxidized by UV light radiation with aqueous H2O2 over SFC/TiO2 in a closed suspension system (CSS) to understand structural characteristics of 4 typical Chinese coals. Raw and oxidized coals were dried and extracted with acetone thoroughly to ensure residue extraction. Meanwhile, the extracts were analyzed using a gas chromatograph/mass spectrometer. The results show that organic matters (OMs) in coals can be converted into a large number of oxygen-containing organic compounds (OCOCs), mainly containing ketones, esters, alcohols, etc. Oxidizing species such as hydroxyls, hydroperoxyl, and alkyl radicals are excited by light irradiation and substitute for hydrogen atoms of methyls and methylenes of acenes or branched-chain alkanes in coals. Acetic acid and acetaldehyde can be formed and dissolved in aqueous solution in the oxidation reaction. The yields can be improved with the enhancement of the oxidation effect.
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MATSUBARA, Kenji, and Mamoru YANAGIUCHI. "The Application of Supercritical Fluid Extraction for Petroleum and Coal Chemistry." Journal of Japan Oil Chemists' Society 35, no. 4 (1986): 287–92. http://dx.doi.org/10.5650/jos1956.35.287.

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Dissertations / Theses on the topic "Coal Extraction (Chemistry)"

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Shoko, Lay. "The chemistry of the alkali-induced solubilisation of coal." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-02222007-173845.

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Parvez, Arshad. "Alkali Extraction Test as a Predictor for Self-Heating in Coal." TopSCHOLAR®, 1986. http://digitalcommons.wku.edu/theses/1817.

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The self-heating of coal is a serious problem that has always affected the coal industry. Self-heating has been studied around the world for more than 100 years by many investigators, yet no accurate method of predicting self-heating in coal has been developed. The objective of this research was to investigate the factors contributing to the self-heating in coal and to develop methods to predict the self-heating in coal and to develop methods to predict the self-heating susceptibility of various coals. A data bank containing analytical data, transportation histories, and results from laboratory tests was established at Western Kentucky University. A laboratory test that gave very encouraging results is an extraction test using sodium hydroxide solutions. Absorbances of the extract solutions from 15 coal samples obtained from barges of coal shipped from the Illinois Basin coal fields to the New Orleans area compared very well with the incidences of self-heating in the 15 barges. The fact that these coals were shipped in the summer when conditions are more favorable for self-heating to take place may have led to the strong correlation of the alkali extract solution absorbances and the final temperatures of the coal in the barges. Tests with coal samples obtained from barges shipped in the other seasons of the year did not yield very good correlations. The poor correlation between self-heating and the alkali extraction test absorbances was due to the lack of accurate temperature data, since the temperature of the coal at the time of loading was not available. The correlation of the absorbances of the extract solutions with parameters such as Btu/lb, oxygen, sulfate sulfur, and free-swelling index was very good.
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Haupt, Petronella. "Effective solvent extraction of coal and subsequent separation processes." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08282007-113611.

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Thesis (M. Eng.)(Chemical Engineering)--University of Pretoria, 2006.
Accompanied by a CD-ROM containing Matlab programs. Includes bibliographical references. Available on the Internet via the World Wide Web.
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Purushothama, Shobha. "A Study of the Effect of the Extraction Procedure in the Analysis of Organic Compounds Adsorbed on Coal Ash." TopSCHOLAR®, 1996. http://digitalcommons.wku.edu/theses/817.

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The organic compounds found adsorbed on coal fly ash have been a cause for concern since the early days of the industrial revolution. A vast majority of the compounds reported as being adsorbed on the ash are polyaromatic hydrocarbons (PAHs). This study represents an attempt to evaluate the parameters involved in the extraction, detection and quantitation of these organic compounds. Though no definite conclusions could be reached as to the most efficient method of extraction, interesting results were obtained with regarding the choice of the solvent and the temperature programming on the GC/MS used for analysis. The solvent of choice appears to be methylene chloride. A slow heating rate appears to give better results as compared to one in which the components elute out in a short time.
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Akinyemi, Segun Ajayi. "Geochemical and mineralogical evaluation of toxic contaminants mobility in weathered coal fly ash: as a case study, Tutuka dump site, South Africa." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1226_1360593017.

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The management and disposal of huge volumes of coal combustion by products such as fly ash has constituted a major challenge to the environment. In most cases due to the inadequate alternative use of coal fly ash, the discarded waste is stored in holding ponds, slag heaps, or stock piled in ash dumps. This practice has raised concerns on the prospect of inorganic metals release to the surface and groundwater in the vicinity of the ash dump. Acceptable scientific studies are lacking to determine the best ash disposal practices. Moreover, knowledge about the mobility patterns of inorganic species as a function of mineralogical association or pH susceptibility of the dry disposed ash dump under natural weathering conditions are scarce in the literature. Fundamental understanding of chemical interactions of dry disposed ash with ingressed CO2 from atmosphere, percolating rain water and brine irrigation within ash disposal sites were seen as key areas requiring investigation. The mineralogical association of inorganic species in the dry disposed ash cores can be identified and quantified. This would provide a basis for understanding of chemical weathering, mineralogical transformations or mobility patterns of these inorganic species in the dry ash disposal scenario. The current study therefore aims to provide a comprehensive characterisation of weathered dry disposed ash cores, to reveal mobility patterns of chemical species as a function of depth and age of ash, with a view to assessing the potential environmental impacts. Fifty-nine samples were taken from 3 drilled cores obtained respectively from the 1 year, 8 year and 20-year-old sections of sequentially dumped, 
weathered, dry disposed ash in an ash dump site at Tutuka - a South African coal burning power station. The core samples were characterized using standard analytical procedures viz: X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transforms infrared (FTIR) techniques, Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and Acid neutralisation capacity (ANC) test. A modified sequential extraction (SE) method was used in this study. The chemical partitioning, mobility and weathering patterns in 1 year, 8 year and 20-year-old sections of the ash dump were respectively investigated using this modified sequential extraction scheme. The sequence of the extractions was as follows: (1) water soluble, (2) exchangeable, (3) carbonate, (4) iron and manganese and (5) residual. The results obtained from the 5 steps sequential extraction scheme were validated with the total metal content of the original sample using mass balance method. The distribution of major and trace elements in the different liquid fractions obtained after each step of sequential extraction of the 59 drilled core samples was determined by inductively coupled plasma mass spectrometry (ICPMS). The data generated for various ash core samples were explored for the systematic analysis of mineralogical transformation and change in ash chemistry with ageing of the ash. Furthermore, the data was analyzed to reveal the impact of ingressed CO2 from atmosphere, infiltrating rain water and brine irrigation on the chemistry of ash core samples. Major mineral phases in original ash core samples prior to extraction are quartz (SiO2) and mullite (3Al2O3·
2SiO2). Other minor mineral phases identified were hematite (Fe2O3), calcite (CaCO3), lime (CaO), anorthite (CaAl2Si2O8), mica (Ca (Mg, Al)3 (Al3Si) O10 (OH)2), and enstatite (Mg2Si2O6). X-ray diffraction results show significant loss of crystallinity in the older ash cores. The presence of minor phases of calcite and mica in dry disposed ash cores are attributed to reduction in the pore water pH due to hydration, carbonation and pozzolanic reactions. The X-ray diffraction technique was unable to detect Fe-oxyhydroxide phase and morealuminosilicate phases in ash core samples due to their low abundance and amorphous character. X-ray fluorescence results of the original ash core samples showed the presence of major oxides, such as SiO2, Al2O3, Fe2O3, while CaO, K2O, TiO2, Na2O, MnO, MgO, P2O5, and SO3 occur in minor concentrations. The ratio of SiO2/Al2O3 classified the original core samples prior to extraction as a silico-aluminate class F fly ash. The ternary plot of major elements in 1-year-old ash core samples was both sialic and ferrocalsialic but 8 year and 20-year-old ash core samples were sialic in chemical composition. It is noteworthy that the mass % of SiO2 varies through the depth of the core with an increase of nearly 3 %, to 58 mass % of SiO2 at a depth of 6 m in the 1-year-old core whereas in the case of the 8-year-old core a 2 % increase of SiO2 to a level of 57.5 mass % can be observed at levels between 4-8 m, showing dissolution of major components in the matrix of older ash cores.. The Na2O content of the Tutuka ash cores was low and varied between 0.6-1.1 mass % for 1-year-old ash cores to around 0.6-0.8 mass % for 8-year-old ash cores. Sodium levels were higher in 1-year-old ash cores compared to 8 year and 20-year-old ashcores. Observed trends indicate that quick weathering of the ash (within a year) leached out Na+ from the ash dump. No evidence of Na+ encapsulation even though the ash dump was brine irrigated. Thus the dry disposal ash placement method does not result in a sustainable salt sink for Na-containing species over time. The total content of each of the elements in 1 year and 20-year-old ash cores was normalised with their total content in fresh ash from same power station to show enrichment and depletion factor. Major elements such as K+, Mn showed enrichment in 1-year-old ash cores whereas Al, Si, Na+, Ti, Ca, Mg, S and Fe showed depletion due to over time erosion. Trace elements such as Cr, Sr, P, Ba, Pb, V and Zn showed enrichment but Ni, Y, Zr showed depletion attributed to over time erosion. In 20-year-old ash cores, major elements such as Al, Na+ and Mn showed enrichment while Si, K+, Fe, Mg and Ca showed depletion highlighting their mobility. Trends indicated intensive flushing of major soluble components such as buffering constituents (CaO) by percolating rain water. The 1-year-old and 20-year-old coal ash cores showed a lower pH and greater loss/depletion of the soluble buffering constituents than the 2-week-old placed ash, indicating significant chemical weathering within a year. Based 
on ANC results the leaching behaviours of Ca, Mg, Na+, K+, Se, Cr, and Sr were found to be controlled by the pH of the leachant indicating high mobility of major soluble species in the ash cores when in contact with slightly acid rain water. Other investigated toxic metals such as As, Mo and Pb showed amphoteric behaviour with respect to the pH of the leachant. Chemical alterations and formation of transient minor secondary mineral phases was found to have a significant effect on the acid susceptibility and depletion pattern of chemical species in the core ash samples when compared to fresh ash. These ANC results correlated well with the data generated from the sequential extraction scheme. Based on sequential extraction results elements, showed noticeable mobility in the water soluble, exchangeable and carbonate fractions due to adsorption and desorption caused by variations in the pore water pH. In contrast, slight mobility of elements in the Fe and Mn, and residual fractions of dry disposed fly ashes are attributed to the co-precipitation and dissolution of minor amount of less soluble secondary phase overtime. The 1-year-old dry disposed ash cores were the least weathered among the 3 drilled ash cores. Therefore low concentration of toxic metals in older ash cores were ascribed to extensive weathering with slower release from residual mineral phases over time. Elements were found to associate with different mineral phases depending on the age or depth of the core samples showing greater heterogeneity in dispersion. For instance the average amount of total calcium in different mineral associations of 1-year-old ash cores is as follows
water soluble (10.2 %), exchangeable (37.04 %), carbonate (37.9 %), Fe and Mn (7.1 %) and residual (2.97 %). The amount of total Na+ in different mineral phases of 1-year-old ash cores followed this trend: water soluble (21 %), exchangeable (11.26 %), carbonate (2.6 %), Fe and Mn (4.7 %) and residual (53.9 %). The non-leachable portion of the total Na+ content (namely that contained in the residual fraction) in the 1-year-old ash core samples under conditions found in nature ranged between 5-91 %. This non-leachable portion of the Na+ showed the metastability of the mineral phases with which residual Na+ associates. Results showed older ash cores are enriched in toxic elements. Toxic elements such as As, B, Cr, Mo and Pb are enriched in the residual fraction of older ash cores. For instance As concentration in the residual fraction varied between 0.0003- 0.00043 mg kg-1 for 1-year-old ash cores to around 0.0003-0.0015 mg kg-1 for 20-year-old ash cores. This suggests that the older ash is enriched in toxic elements hence dust from the ash dump would be toxic to human health. The knowledge of mobility and ecotoxicological significance of coal fly ash is needed when considering its disposal or reuse in the environment. The mobility and ecotoxicology of inorganic metals in coal fly ash are determined by (i) mineralogical associations of inorganic species (ii) in-homogeneity in the ash dumps (iii) long and short term exposure to ingress CO2 and percolating rain water. Management issues such as inconsistent placement of ash in the dumps, poor choice of ash dump site, in-homogeneity in brine irrigation, no record of salt load put on the ash dumps and lack of proper monitoring requires improvement. The thesis provides justification for the use of the modified sequential extraction scheme as a predictive tool and could be employed in a similar research work. This thesis also proved that the dry ash disposal method was not environmental friendly in terms of overall leaching potential after significant chemical weathering. Moreover the study proved that the practice of brine co-disposal or irrigation on ash dumps is not sustainable as the ash dump did not act as a salt sink.

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Rushwaya, Mutumwa Jepson. "Purification of coal fly ash leach solution by solvent extraction." Thesis, 2016. http://hdl.handle.net/10539/21055.

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A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Metallurgy and Materials Engineering), May 2016
The solvent extraction of iron and titanium from solution generated by the two-step sulphuric acid leaching of coal fly ash by Primene JMT was investigated. The influence of hydrogen ion concentration, Primene JMT concentration, aqueous to organic volume phase ratio and temperature on the extraction of iron and titanium was determined by the use of Design of Experiments. Hydrogen ion concentration and the interaction between the aqueous to organic volume phase ratio with Primene JMT concentration had a significant effect on the extraction of iron while temperature did not. Hydrogen ion concentration and temperature did not have a significant effect on the extraction of titanium, while the interaction between Primene JMT concentration and aqueous to organic volume phase ratio had a significant effect. Extraction improvement tests showed that at a hydrogen ion concentration of 0.28M, 88% iron and 99% extraction of titanium from coal-fly ash leach solution could be achieved. Construction of a McCabe-Thiele diagram showed that a four-stage solvent extraction system with Primene JMT could reduce the iron and titanium concentration in the coal fly ash leach solutions to below 0.05g/L
GS2016
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Ludere, Tshimangadzo Margaret. "The effect of diabietic acid on the coking of oxidised solvent - extracted coal." 2006. http://upetd.up.ac.za/thesis/available/etd-04172008-140302.

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Akinyemi, Segun Ajayi. "Geochemical and mineralogical evaluation of toxic contaminants mobility in weathered coal fly ash : as a case study, Tutuka dumpsite, South Africa." Thesis, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_6004_1325666445.

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The current study therefore aims to provide a comprehensive characterisation of weathered dry disposed ash cores, to reveal mobility patterns of chemical species as a function of depth and age of ash, with a view to assessing the potential environmental impacts. Fifty-nine samples were taken from 3 drilled cores obtained respectively from the 1 year, 8 year and 20-year-old sections of sequentially dumped, weathered, dry disposed ash in an ash dump site at Tutuka - a South African coal burning power station.
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Books on the topic "Coal Extraction (Chemistry)"

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Hessley, Rita K. Coal science: An introduction to chemistry technology, and utilization. New York: Wiley, 1986.

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1930-, Petruk W., Rule A. R, International Conference on Applied Mineralogy (1991 : Pretoria, South Africa), TMS Process Mineralogy Symposium (1993 : Denver, Colo.), and SME Process Mineralogy Symposium (1993 : Reno, Nev.), eds. Process mineralogy XII: Applications to environment, precious metals, mineral benefication, pyrometallurgy, coal, and refractories. Warrendale, Pa: Minerals, Metals & Materials Society, 1994.

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Book chapters on the topic "Coal Extraction (Chemistry)"

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"- Solvent Extraction." In The Chemistry and Technology of Coal, 364–85. CRC Press, 2012. http://dx.doi.org/10.1201/b12497-16.

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Conference papers on the topic "Coal Extraction (Chemistry)"

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"Molecular composition - inhibition activity relationships for humic substances narrow fractions sets obtained by solid-phase extraction." In Sixth International Conference on Humic Innovative Technologies "Humic Substances and Eco-Adaptive Technologies ”(HIT – 2021). Non-Commercial Partnership "Center for Biogenic Resources "Humus Sapiens" (NP CBR "Humus Sapiens"), 2021. http://dx.doi.org/10.36291/hit.2021.mikhnevich.001.

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Humic substances (HS) have a wide spectrum of biological activity including inhibitory activity against β-lactamases.1 The latter are capable of hydrolyzing beta-lactam antibiotics and represent one of the main pathways of bacterial antibiotic resistance. HS are characterized by low toxicity and good solubility in water. A use of HS for therapeutic purposes is hindered by extreme molecular heterogeneity and high level of isomeric complexity. Solid-phase extraction (SPE) fractionation in combination with ultra-high resolution mass spectrometry (FTICR MS) is a promising method to simplify this molecular system and isolate the most active components of HS. The aim of this work was to test various SPE fractionation schemes as an approach to directed isolation of the components with the given activity from HS. The sample of coal humic acids (CHA-G) was isolated from the commercial sodium humate “Genesis” and separated using SPE cartridge according to gradients in polarity1 and acidity2 inherent within the molecular components of HS. Inhibitory activity against β- lactamase TEM-1 and its mutants was measured using chromogenic substrate CENTA. Molecular composition of fractions was determined using FTICR mass spectrometer 15 T solariX (Bruker Daltonics) located at the Collective Use Center of Zelinsky Institute of Organic Chemistry of RAS. Molecular assignments were plotted into van Krevelen diagrams. The diagrams were binned into 20 cells are assigned to seven chemotypes, and occupational densities for each chemotype were calculated after Perminova.3 For the fractions separated by polarity, a substantial difference in the molecular composition was observed. Inhibitory activity grew along with an increase in hydrophobicity. The HS activity increased along with an increase in contribution of condensed tannins and phenylisopropanoids (O/C <0.5, H/C <1.4) and decreased along with contribution of hydrolyzed tannins (O/C> 0.5, H/C <1.4). The similar analysis was conducted for the fractions separated with regard to pKa value of the dominating functional groups. The most isomeric complex molecular components were defined, which can be found in different HS fractions, but they are identical in elemental composition. The data obtained make it possible to choose the most efficient fractionation method that effectively lowers the molecular complexity of HS and makes it possible to isolate the most active HS fractions. SPE-fractionation in combination with 2D chromatography is going to be used in our future studies to achieve high resolution separation and more reliable “molecular composition-activity” relationships. Further research might bring substantial advance in the field of directed design of biologically active humic-based materials and compositions. Acknowledgements. This work was supported by the grant of the Russian Science Foundation no 21-73-20202. The center of collective use of the Zelinsky IOC RAS is appreciated. The research was conducted in the framework of the Scientific-Educational School of the Lomonosov MSU “Future of the plant and global environmental change”. References 1. Mikhnevich et al., ACS Omega, 2021, https://doi.org/10.1021/acsomega.1c02841 2. Zherebker et al., Environ. Sci. Technol. 2020, 54, 2667−2677 3. Perminova, I. V. PAC, 2019, 91(5), 851
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