Properties Of Brown Coal Research Articles

Composition and Properties of Brown Coal from the Bodonskoe Deposit in Buryatia

The composition and properties of coal from the Bodonskoe deposit were studied. It was shown that this is low-sulfur (S d = 0.3–1.0%) and medium-ash grade 1B brown coal with a high yield of volatile substances (V daf = 56.1–60.9%). The humic acid content varies from 32.3 to 50.8%. The heat of combustion of coal is Q s daf = 26.0–27.4 MJ/kg. The concentrations of toxic elements in the coal samples are at a background level.

Investigating forward osmosis process for simultaneous preparation of brown coal slurry and wastewater reclamation

The feasibility of using the forward osmosis (FO) process involving brown coal as draw agent to reclaim clean water from dye wastewater is evaluated in this study. It is found that brown coal not only has enough driving force for drawing water from dye wastewater but also can be reconstituted during the FO process, thus resulting in directly usable coal water slurry after appropriate FO time as an energy source equivalent to fossil oil or feedstock for chemical synthesis via gasification. In the FO process, water-drawing effect can significantly enhance the slurryability of brown coal via weakening the moisture holding capacity, decreasing the porosity and achieving the favorable particle size distribution due to the improved grindability. A possible tri-factor water-drawing and reconstitution mechanism of brown coal during the FO process is proposed to explain the effects of FO process on the properties of brown coal. The results indicate that the FO process promises to be a low-cost green process for simultaneous wastewater treatment and preparation of coal water slurry for environmental protection and energy production.

Properties of brown coals as raw materials for processing

The composition and chemical and physicochemical properties of different brown coals as raw materials for deep thermochemical processing were considered. The effect of the modifying treatments of coals on their properties was studied. Correlation relationships between the calcium content of coals and the structure characteristics and reactivity of the organic matter were established. It was found that coals with an increased calcium content were characterized by a dense rigid supramolecular structure and low activity on hydrogenation in hydrogen-donor solvents. In contrast to this, calcium compounds exerted a considerable catalytic effect on the reaction rate and the composition of the resulting gaseous products in high-temperature oxidative processing (oxidative destruction in air and steam gasification).

Characteristic properties of brown coal lithotypes from the Tevshiin Govi deposit in Mongolia

The organic and mineral compositions and the technological properties of brown coals of the clarain and fusain types from the Tevshiin Govi coal deposit in Mongolia are characterized. The reactivity of petrographical lithotypes toward the process of ozonolysis was evaluated, and the composition of their ozonolysis products was studied.

Paramagnetic properties of brown coal from the Kiyaktinskoe deposit before and after mechanical treatment and electron irradiation

Results of a study of the paramagnetic characteristics of brown coal from the Kiyaktinskoe deposit (Kazakhstan) in a native state and after mechanical treatment and electron irradiation are reported. The effects of these actions on changes in the paramagnetic properties of the test coal and on the intensification of a coal hydrogenation process are discussed. It was found that the concentration of free radicals changed only slightly after mechanical treatment in a ball mill at room temperature in an atmosphere of air, whereas the concentration of Fe3+ ions noticeably increased. Upon the electron irradiation of coal, the dose dependence of the concentration of free radicals passed through a maximum at a dose of 100 kGy. At the same radiation dose, the yield of a kerosene-gas oil fraction upon the hydrogenation of Kiyaktinskoe coal increased, and the total yield of liquid products increased upon the irradiation of coal and a catalyst (bauxite 094) to a dose of 100 kGy. It was hypothesized that Fe3+ ions, which were additionally formed upon coal grinding and irradiation, can serve as an internal catalyst in the course of coal hydrogenation.

00/00615 Metallic ion exchange properties of brown coals— evaluation of structural changes in low-temperature heat-treated coals by ion exchange

00/00615 Metallic ion exchange properties of brown coals— evaluation of structural changes in low-temperature heat-treated coals by ion exchange

96/06635 Ion exchange properties of brown coals

96/06635 Ion exchange properties of brown coals