Petrographic characterization, variations in chemistry, and paleoenvironmental interpretation of Colombian coals

Rojas, Olga Patricia Gómez; Blandón, Astrid; Perea, C.G.; Mastalerz, María

doi:10.1016/j.coal.2020.103516

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…2A,B). Variations in mineral content were also observed, notably in clay minerals, quartz and pyrite, as is frequent in Colombian Cretaceous coals [27], [28], [29], [30], [31]. The reactive macerals, which are of interest here as they generate the optical textures for defining CAQ, included vitrinite, liptinite, and ∼1/3 of the semifusinite present in the samples (65.28 to 81.73%).…”

Section: Methodsmentioning

confidence: 86%

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

et al. 2020

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This study developed a theoretical model for the determination of the Coke Anisotropy Quotient (CAQ) of semi-coke from the properties of its precursor coal. This is an useful parameter to define the resistance and reactivity of semi-coke in the blast furnace. For 36 semi-coke samples, a textural analysis was performed alongside a fluidity test to determine the real CAQ. The main textures observed were: isotropic and circular for high volatile bituminous coals (HVB); lenticular and fine ribbons for the medium volatile bituminous coals (MVB); and medium and thick ribbons for the low volatile bituminous coals (LVB). The CAQ varied in a range from 1 to 11. A principal component analysis (PCA) and multiple regression allowed to discriminated the importance of certain coal properties, in determining the CAQ to be recognized and to estimate parameters of the mathematical model. The statistical analysis suggested that CAQ can be best predicted from the fluidity, volatile matter, and Ro of the parent coals. The veracity of this model result was then tested using a second dataset from Poland. This work optimizes the usefulness of standard datasets in the prediction of CAQ's offering a means of quality control that could be implemented in Colombian coke production.

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Section: Methodsmentioning

confidence: 86%

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

et al. 2020

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“…The surface groups are atoms or groups at the edges of the basic units of the coal chemical structure. They are one of the critical factors that dominate the adsorption properties of coal Figure shows the infrared spectrums of the anthracite samples before and after modification.…”

Section: Resultsmentioning

confidence: 99%

“…They are one of the critical factors that dominate the adsorption properties of coal. 27 Figure 2 shows the infrared spectrums of the anthracite samples before and after modification.…”

Section: Resultsmentioning

confidence: 99%

Synergistic Mechanism of Ultrasonic-Chemical Effects on the CH₄ Adsorption–Desorption and Physicochemical Properties of Jincheng Anthracite

Liang

Kang

et al. 2022

ACS Omega

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Ultrasonic is a new method to enhance coalbed methane recovery. A deeper comprehension of the synergistic mechanisms of combined ultrasonicchemical modification on the CH 4 adsorption−desorption capability and physicochemical properties of coal is necessary for potential field implementation, as the modification of coal reservoirs frequently necessitates the addition of chemical reagents. This paper evaluated the CH 4 adsorption−desorption properties of anthracite modified by sodium dodecyl sulfate (SDS) solution, ultrasonic modification, and combined ultrasonic-SDS modification. Fourier transform infrared spectroscopy, low-temperature nitrogen adsorption, and micro-CT were applied to elucidate the synergistic mechanism of the combined modification. The research results show that the SDS solution reduces the saturated adsorption capacity of anthracite and increases its final desorption rate by dissolving clay minerals and the physical adsorption masking effect of SDS micelles on the coal surface. Some surface groups with low bond energy are broken or evaporated under mechanical vibration and thermal effects generated by ultrasonic. The original fractures are expanded and connected, which changes the adsorption−desorption properties of anthracite. The synergistic effect of the combined modification of ultrasonic-SDS can promote the penetration range and chemical reaction efficiency of the SDS solution, which expands the effective range of ultrasonic. After combined modification, the amount of aromatics, oxygencontaining functional groups, and aliphatic hydrocarbons on the surface of coal is reduced. The connected porosity of coal samples accounts for 91.5% of the total porosity. As a result, the saturated adsorption capacity of anthracite reduces by 26.7%, and the final desorption rate increases by 28.0%. The effect of the combined ultrasonic-chemical modification is better than that of a single modification.

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“…The temperature in the La Guajíra region varies between a minimum of 0 • C and a maximum of 30 • C. It is characterized by having the driest climate in Colombia [35]. The main economic activities in the region consist of mineral coal mining, tourism activities related to the Caribbean Sea, agriculture (sugar cane, rice, sesame, sorghum, cassava, cotton, and tobacco), and the raising of livestock (goats) [35,36]. Sample site A consists of an abandoned open pit coal mine that was also utilized as a dumping area for coal fly ash.…”

Section: Studied Areasmentioning

confidence: 99%

Hazardous Elements in Sediments Detected in Former Decommissioned Coal Mining Areas in Colombia: A Need for Environmental Recovery

et al. 2023

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This study demonstrates an investigation into nanomineralogical and geochemical evolution for the detection of hazardous elements from old, abandoned coal mining deposits capable of causing negative environmental impacts. The general objective of this study is to evaluate the number of nanoparticulate chemical elements in sediments collected during the years 2017 and 2022 from deactivated coal mining areas in the La Guajíra and Cesar regions of Colombia. Sediments were collected and analyzed from areas that experienced spontaneous coal combustion (SCC). The analysis consisted of traditional mineralogical analysis by X-ray diffraction and Raman spectroscopy, nanomineralogy by field emission scanning electron microscope-FE-SEM, and high-resolution transmission electron microscope-HR-TEM (energy dispersive X-ray microanalysis system-EDS). The analyzed sediment samples contained high proportions of amorphous materials containing the chemical elements As, Cl, Hg, Mo, Pb, Sb, and Se. This study emphasizes the need to implement environmental recovery projects at former, now abandoned coal extraction areas located in the investigated region, as they have negative effects on the environment and human health across large regions.

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Petrographic characterization, variations in chemistry, and paleoenvironmental interpretation of Colombian coals

Cited by 8 publications

References 19 publications

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

Synergistic Mechanism of Ultrasonic-Chemical Effects on the CH₄ Adsorption–Desorption and Physicochemical Properties of Jincheng Anthracite

Hazardous Elements in Sediments Detected in Former Decommissioned Coal Mining Areas in Colombia: A Need for Environmental Recovery

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Petrographic characterization, variations in chemistry, and paleoenvironmental interpretation of Colombian coals

Cited by 8 publications

References 19 publications

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

Synergistic Mechanism of Ultrasonic-Chemical Effects on the CH4 Adsorption–Desorption and Physicochemical Properties of Jincheng Anthracite

Hazardous Elements in Sediments Detected in Former Decommissioned Coal Mining Areas in Colombia: A Need for Environmental Recovery

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Synergistic Mechanism of Ultrasonic-Chemical Effects on the CH₄ Adsorption–Desorption and Physicochemical Properties of Jincheng Anthracite