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Article
Investigation of the Sorption Activity of Native Coals to Atmospheric Oxygen
The influence of a gas atmosphere during sample preparation, granulometric composition, the duration of contact with air, and the stage of metamorphism on the sorption of oxygen by coals from the atmosphere wa...
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Article
Influence of Coal Processing with a Suspension of Blast Furnace Slag on Changes in the Physicochemical Properties of the Surface
The properties and efficiency of a solid–liquid suspension based on ground blast furnace slag, which is used to deactivate the processes of oxidation and spontaneous combustion of coals, have been studied. It ...
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Article
Thermogravimetric Study of Ozone-Modified Coal Tar
Thermogravimetric analysis is used for preliminary assessment of how ozonation affects the yield of coal tar factions in distillation. Since the distillation temperature of light fractions matches the main pea...
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Article
Change in Grain-Size Composition of Coal in Toothed Screw Crushing on a Laboratory Scale
The article presents the results of toothed screw crushing of coal on a laboratory scale. The samples are the marketable coal from different deposits in Russia, Kazakhstan and Kyrgyzstan. From the analysis of ...
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Article
Effect of the Chemical Composition of Coals on Surface Wettability and Filtration Properties
The method of liquid filtration through a layer of coal powder was used for a comprehensive characterization of surface wettability in conjunction with the determination of the contact angle. The effect of the...
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Article
Influence of Air Contact on the Surface Wettability of Coal and Its Filtration and Flotation Properties
In a laboratory experiment, samples of SS coal prepared in an inert atmosphere (nitrogen) and by standard methods in air are compared. The surface changes of the coal particles are studied by IR spectral analy...
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Article
Interaction of Freshly Exposed Low- and Medium-Grade Coal with the Air
The chemical composition of low- and medium grade Russian coal (ranks G, DZh, and Zh) on first exposure to the air is analyzed. The changes in the coal’s organic matter are recorded by means of diffuse-reflect...
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Article
Influence of Surface Oxidation on the Wettability and Filtration Properties of Coal
Most processes in coal extraction (hydraulic fracturing, plugging of cracks, irrigation of the exposed mass with deactivating liquid) and initial processing (enrichment) depend on the wetting properties of the...
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Article
Open AccessChanges in the Properties of Native Low-Metamorphozed Coal in Contact with Air
Data on the analysis of the chemical composition and physicochemical properties of native low-metamorphosed coal at the initial moment of its contact with the air are presented. Diffuse reflectance IR spectros...
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Article
Influence of Moisture Content of the Reactivity of Coal in Ozone
Ozone is employed to accelerate oxidation and hence shorten experiments regarding the susceptibility of coal to oxidation and self-ignition. To avoid profound oxidative destruction of the coal sample, experime...
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Article
Influence of Particle Size on Oxidation by Ozone for Coal of Limited Metamorphic Development
Ozone may be used to accelerate the oxidation of coal and hence to permit more rapid determination of its susceptibility to self-heating and self-ignition. In the present research, the coal is oxidized at 25°C...
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Article
Coal Oxidation and Surface Wettability by Cement Solution
The change in surface wettability of long-flame coal with little metamorphic development on first contact with air is analyzed. The wetting liquids considered are filtrates of cement suspensions of different c...
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Article
Reactivity of Coal with Ozone
The susceptibility of coal to oxidation with stimulation by low concentrations of ozone (~10 mg/L) is considered. The influence of the coal’s metamorphic stage and its specific surface on its oxidation rate is...
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Article
Improving the Flotation Properties of Emulsions of Spent Motor Oil by Ozonization
The effect of ozonizing spent mineral oil on the dispersion of the emulsion during emulsification by blade impellers is considered. The disperse composition of the emulsion is determined by laser diffraction a...
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Article
Intensification of Coal Flotation by Means of Air Microbubbles
The reagent flotation of regular coal by means of liquid containing gas microbubbles is considered. Various sequences of microbubble supply to the flotation chamber are tested and characterized. The supply of ...
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Article
Influence of Reagent Emulsification on Coal Flotation in the Presence of Gas Microbubbles
The influence of the dispersion conditions for the apolar flotation agent (collector) on the size distribution of the droplets within the emulsion is established by laser differential analysis of the particle ...
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Article
Disperse Composition of a Coal Flotation Reagent (Spent-Oil Emulsion)
The dispersity of an emulsion of treated mineral oil used as a coal-flotation reagent is studied by laser diffraction. A finely disperse oil emulsion in water is produced by selecting optimal duration and inte...
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Article
INFLUENCE OF DISPERSIVENESS OF EMULSION COMPOSED OF OILY REAGENTS ON COAL FLOTATION RESULTS
Dispersiveness of emulsion composed of oily reagents is estimated using the method of laser diffraction in experimental and in-process tests of flotation of slurry coal. Effect of agitation level in emulsifica...
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Article
Assessment of the Likelihood of Underground Coal Oxidation and Self-Ignition: A Review
Standard and alternative methods of assessing the likelihood of coal oxidation and self-ignition in the bed are analyzed. These methods are based on the change in the petrographic, physicomechanical, chemical,...
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Article
Dependence of Coal Surface Wettability on the Petrographic Composition
Based on a comparison of elemental analysis data and IR- and 13C NMR-spectroscopic data, principal differences in the chemical compositions of lithotypes isolated from Kuznetsk Basin coals of different ranks base...
