S. A. Semenova

Processing low-grade oxidized coal to produce effective carbon sorbents

High-porosity sorbents may be produced by carbonization of low-grade oxidized coal in the presence of alkali.

Porous structure of adsorbents based on naturally oxidized Kuznets Basin coal

The specific surface, total pore volume, and volume of micropores and mesopores are determined for carbon sorbents obtained by the thermolysis of naturally oxidized Kuznets Basin coal, in the presence of potassium hydroxide (mass ratio of KOH and coal RKOH = 1.0 g/g). The porous characteristics of the adsorbents are calculated on the basis of the isotherms of low-temperature (77 K) nitrogen adsorption and desorption.

Dependence of the water wettability of the surfaces of fossil coals on their structure and properties

The dependence of the water wettability of coal surface on the structure and properties of coals of different stages of diagenesis and metamorphism was studied based on the evaluation of the angles of contact. It was found that the caking coals of Zh and K ranks exhibited maximum hydrophobic properties. Hydrophilic properties were most pronounced in brown coals and low-rank black coals with the highest concentrations of hydroxyl and carboxyl groups and a developed porous structure.

Effect of modification of granulated activated carbons with ozone on their properties

Modification of AG-OV-1 activated carbon with an ozone-oxygen mixture was studied. Changes in the porosity, state of the surface, and adsorption capacity of ozonized samples were examined in relation to the oxidation duration. Explanation are suggested for the patterns obtained.

Coal flotation by ozonized spent motor oil

The influence of ozonization on the composition and flotation properties of spent motor oil is investigated. Preliminary ozonization increases the proportion of low-boiling components in the spent oil, reduces its viscosity, and improves its flotation properties in the enrichment of coking coal.

Modification of Mongolian coals using a low-temperature oxygen plasma

The results of a study of the effect of the treatment of coals from the Khar Tarvagatai, Nuurst Khotgor, and Khushuut deposits of Mongolia in a low-temperature oxygen plasma are presented in this article.

Influence of alkali treatment on the properties of adsorbents based on naturally oxidized Kuznets Basin coal

The influence of alkali treatment on the properties of adsorbents derived from naturally oxidized Kuznets Basin coal is considered. The alkali used in the research is potassium hydroxide, when the mass ratio of KOH and coal is RKOH = 1.0 g/g. The pore structure is compared for two series of samples obtained by different methods: steeping of the coal with aqueous alkali solution and subsequent drying; and mechanical mixing with solid KOH.

Modification of coal tar in low-temperature oxygen plasma

Oxidative modification of coal tar by activated components of low-temperature plasma is considered. Such modification of tar is accompanied by polarization and polycondensation processes, with consequent increase in thermostability of the product.

Ozonation of coal vitrinites of different metamorphism degrees in gas and liquid phases

The comparative analysis of the dynamics of accumulation of oxygen-containing groups in coals of different metamorphism degrees under their ozonation in the gas phase and in chloroform has been performed. The coals of the middle stage of metamorphism demonstrate the highest reactivity. The ozonation in chloroform proceeds with a higher intensity.

Effect of ozonation on the composition of crude coal-tar benzene

The effect of ozonation on the composition of crude benzene produced by the coal-tar chemical industry was studied.