Vol 53, No 4 (2019)

The results of the petrographic and chemical analysis of brown coal from the Mugunsk deposit in the Irkutsk Coal Basin are presented. The most common groups of macerals and a number of toxic and potentially toxic elements were identified.

The production of carbon sorbents based on special fine coke using a combination of steam and gas activation (by gas after the carbonization of Shubarkol coal with carbon dioxide and superheated water vapor) and chemical activation (by sodium hydroxide) was studied. Their textural and sorption properties were characterized. The necessity of separating the carbon and mineral parts of the special fine coke by elutriation in water was shown. The high adsorption capacity of the samples for gold ions was established (the recovery was 99.4–99.9%). The method for the production of a sorbent based on special fine coke in order to extract gold from cyanide solutions and the optimal conditions for its adsorption were recommended.

The effect of extrusion conditions on the properties of peat briquettes was experimentally studied with the use of an industrial crank press with an open matrix. Regression equations were obtained for determining the density, mechanical strength in axial compression, hardness, and water absorption of fuel peat as functions of compacting pressure and feed moisture content. The dependences of the density, mechanical compression strength, and hardness of briquettes on the compacting pressure have a threshold behavior, which is responsible for their maximally accessible values at a specified level of humidity. Conditions for the production of fuel were optimized to be consistent with the most effective regimes of extrusion from an energy point of view.

The results of a study on the hydrogenation of a mixture of anthracene and phenanthrene in the presence of nanocatalysts (Fe₃O₄ and β-FeOOH) and catalytic additives (microspheres obtained from the ash of coals from the Republic of Kazakhstan and nickel and cobalt additives supported on the microspheres) are presented. The efficiency of a wet mixing method for the preparation of nickel and cobalt oxide catalytic additives on the microspheres in the process of the hydrogenation of a mixture of anthracene and phenanthrene was shown. The hydrogenation process of a mixture of polyaromatic hydrocarbons was represented as a combination of hydrogenation and destruction reactions. The individual chemical composition of the hydrogenation products of a mixture of anthracene and phenanthrene was investigated. The activity and selectivity of the catalysts and catalytic additives in the hydrogenation process of a mixture of polyaromatic hydrocarbons were established.

A procedure for the production of activated shungite by the carbonization and activation of shungite rock from the Bakyrchik deposit subjected to flotation concentration is presented. The elemental composition of the test sample was determined and the surface morphology was studied; the type of shungite carbon modification was revealed, and its structural and functional characteristics were given. The main physicochemical characteristics of the sample were determined. It was found that carbon materials with a more developed and ordered surface structure and increased porosity can be obtained as a result of the flotation enrichment of shungite and its subsequent thermal activation. With the use of the BET method, it was established that the thermal and steam–gas activation of shungite leads to a significant increase in the specific surface area of the sample and in the specific pore volume and to a decrease in the average pore size.