abstract the objective of this work is to study the feasibility of using vegetable oils which are available, renewable and nonpolluting energy resources as flotation reagents for the recovery of coal from coal fines wastes. To comply with this objective, crude soc soyabean oil and a used AB olive oil of household origin were used as collectors in the flotation of the fines fraction of a coal mechanism of shale oil as an effective collector for oxidized coal flotation: from bubbleparticle attachment and detachment point of view. fuel 2019, 255 enhancement of oxidized coal flotation by preconditioning with positive-charged microbubbles. international journal of coal preparation and utilization 2017,
In this work, the effect of ultrasonic pretreatment time on oxidized coal flotation was studied. analytical techniques, such as particle size distribution scanning electron microscopy x-ray photoelectron spectroscopy contact angle measurement, and specific surface areapore analysis, were used to examine the changes in the physicochemical characteristics of the coal small, and the use of oil alone cannot improve fine coal flotation performance. oxidation alters both physical and chemical properties of the coal surface and reduces the floatability. the surface oxidation of coal is reflected by decrease in pH of the coal fine slurry. In fine coal, oxidation by weathering, or coals kept for a long
hours ago the strengthening mechanism of oxidized coal flotation using shale oil was systematically explained based on studies of bubble-particle attachment and detachment by induction time, wrap angle, and bubble-particle attachment and detachment visualization tests. flotation results prove that shale oil can evidently improve the clean coal yield.fuel oil is employed in the flotation medium as a collector andor dispersing reagent. representative fuel oils include diesel oil, kerosene, bunker fuel oil, mixtures thereof and the like. the fuel oil can generally be advantageously employed in a ratio of from about 0.02 to about 2.5 kilograms fuel oil per metric ton of coal flotation feed.
when a micro-bubble flotation technique was employed to float appalachian coal, it produced a cleaner coal product than conventional macro-bubble flotation. general kinetic model was proposed to represent the rate of flo tation of coal. for two appalachian coals, the model successfully represented the flotation kinetics of uniformly sized coal.disclosed is an improved process wherein coal particles are beneficiated by froth flotation under coal froth flotation conditions to separate the desired coal particles from remaining unwanted ash and like gangue material. the improvement of the present invention comprises conducting the froth flotation in the presence of an effective proportion of a hydrophobic, non-ionic promotor which is a
however, it should be pointed out that for the flotation of naturally hydrophobic molybdenite mos a hydrocarbon oil is added to enhance its hydropho-2 bicity -similar to coal flotation. In molybdenite or coal flotation, the oily collector must act by spreading rather than adsorption.the flotation of low-quality russian and mongolian coal by means of spent motor oil is investigated. ozonization is used to improve the flotational properties of the spent oil. the optimal ozonization depth of oil used to enrich coal of poor metamorphic development is gkg. ozonization increases the oils content of oxygen-bearing heteropolar compounds, which determine its flotation
the objective of this study is to explain the different flotation responses observed in oxidized coal flotation when using a nonpolar flotation collector, dodecane, versus a polar flotation collector, oleic acid. particularly, the effect of each flotation collector on bubblecoal particle attachment was investigated. colloidal probe atomic force microscopy was used to directly measure employment of a latex emulsion prepared from a hydrocarbon, animal or vegetable based oil with a hydrophobic water-in-oil emulsifier and a hydrophilic surfactant in the froth flotation of coal improves coal recovery without increasing the ash content. the emulsifier employed should have an hlb value of 5.0 or less while the surfactant should have an hlb value of 9.0 or higher.
the flotation of low-rank coal suffers poor efficiency with hydrocarbon oils unless it is at a high dose. representative non-polar oil, diesel oil was used as a collector to float a long-frame coal. the feasibility of oxidized paraffin soap was explored to improve flotation performance.flotation performance of the oxidized coal for recovering the low ash concentrate using a mixture of two different types of frother. experimental the non-coking coal from talcher coalfield was used for the study. the proximate analysis of the coal carried out on a moisture-free basis indicates that the ash is 26.8% with 35.7 volatile
abstract: coal fines of -75 were agglomerated using vegetable oils with varying dosages from other parameters under this study were ash rejection and yield. for and oil dosage the yield was found to be 84.93% using castor oil while for sesame oil it was merely 74.22%.the low rank or oxidized coals show unpleasant flotation behaviour. the non-coking coal from talcher, containing 26.8% ash, 4.9% moisture, 35.7% volatile matter and oxygen was used for the investigation. the flotation performance of the weathered coal in a mechanical and column flotation cell was compared at low ash level of about 12%.
3.3.3 hydrophobization of low rank coal by oxidation followed by recovering fine particles that are difficult to recover by flotation. oil agglomeration involves recovering coal fines by oil agglomeration is a well-known process. however, recovering mineral particles with oil agglomeration is yet to be To clean very fine sizes of coal, flotation procedures must be employed. In these the mixture of coal and impurities is fed into a water bath, flota tion reagents are added, and the bath is aerated. the flotation agent adheres to and coats only the coal particles. the
An ultrasonic particle treatment can be used to remove oxidation layers from coal particles so that the surface of oxidized coal particles is re-activated. coal-water-oil and coal-water fuels. ultrasonic grinding and dispersing is used to generate fine-size slurries of coal particles in water or oil. By ultrasonication, a fine-size particle Of particular interest are the development of leaching procedures in the ames wet oxidation process for desulfurizing coal and the cleaning and recovery of coal fines by flotation and oil agglomeration. organic sulfur compounds in coal and the behavior of specific organic sulfur compounds chosen as structural models for the sulfur compounds in coal were studied.
the influence of preliminary coal treatment with spent motor oils on the wettability of the coal surface by water is studied. modification of the oil with ozone and hydrogen peroxide and also by thermal oxidation increases the surface hydration of the treated coal and reduces the wetting of the coal in comparison with the initial apolar oil.the heat of immersion of coal in water and various organic liquids provides a useful means for characterizing the surface of the material, while the oil-water-coal, three-phase contact angle provides a characterization of the coal surface as well as the interactions among oil, water, and coal. such characterizations may provide an indication of how well the coal will respond to cleaning by the
difficult-to-float coal fines of weak hydrophobicity particle-bubble collision, attachment, and detachment are the most critical steps in the flotation process. It is known that the low flotation recovery of fine coal particles is mainly due to the low probability of bubble-particle collision. fundamental analyses of frothflowsheet for the hydrogen production process including all columns, tanks, heat exchangers, etc was completed. material and energy balances for each piece of equipment were also completed for the case of hydrogen produced at 1000 psi and a coal feed to the partial oxidizer. all equipment sizes and materials of construction, as well as the capital cost, were specified for this case.
oxidation of coal and coal pyrite: f.m. doyle, unv.california at berkeley final report of the peaks corresponding to aliphatic configurations decreased dramatically.the latter confirms the fact that thermal oxidation at 230 severely modified the aliphatic structure of coal. the mechanisms of oxidation at 230 were interjreted in terns of classical auto-oxidationthe coalburg seam coal is an example of difficult to float bituminous coal. laboratory tests conducted on coalburg flotation feed sample revealed recovery values around 28% with 15% product ash when using fuel oil as collector under natural pH conditions. detailed study showed that increasing pH from natural value of 5.6 to 7.5 provided a significant improvement in recovery of approximately
process for the flotation of particles of lignitic coal, subbituminous coal or oxidized bituminous coal contained within a slurry of coal and gangue, comprising the steps of dispersing a surfactant throughout the slurry, first conditioning the slurry such that the surfaces of the particles of coal are selectively coated by the surfactant to produce activated particles of coal, dispersing an minerals article effect of dodecane and oleic acid on the attachment between oxidized coal and bubbles mengdi Xu yaowen xing 1,2,, yijun cao 3,4, and xiahui gui school of chemical engineering and technology, china university of mining and technology, xuzhou jiangsu, china; cumtxmdoutlook.com
An excellent separation was obtained by the microbial flotation using a long column which had a lengthdiameter ratio of 12.7. the long column flotation reduced the pyritic sulfur content from 11% to 1.8% when 80% of the feed coal In this paper. the effects of oxidation. pretreatment and dissolved species on coal flotation are discussed along with mechanisms involved. coal oxidation the atmospheric oxidation of coal by weathering or aging is a natural process that involves physical and chemical adsorption of oxygen on the surface of coal and the
oct 01, 2019 oxidized coal particles exhibit poor flotation characteristics with standard flotation chemicals such as fuel oil as collector and mibc as frother. flotation tests performed on oxidized coal extracted from the coalburg seam in the u.s. central appalachia coalfields confirmed the difficulty observed in an operating preparation plant.