Open Access
Access granted
Subscription Access
Vol 59, No 2 (2016)
- Year: 2016
- Articles: 4
- URL: https://ogarev-online.ru/1068-364X/issue/view/13904
Coal and Coke
Properties of Ulug Khem coal. 2. Quality of coke from batch containing Mezhegei coal
Abstract
On the basis of the laboratory coking of production batches at OAO EVRAZ NTMK, including those containing coal from the Mezhegei deposit, a new coking index is proposed. This index is incorporated in a mathematical model for predicting coke quality (CSR and CRI).
41-47
Chemistry
Extraction of humic acids from Kansko-Achinsk lignite
Abstract
A method has been developed for practically complete alkaline extraction of humic acids from Kansko-Achinsk lignite. The maximum yield of humic acids may be ensured by correct selection of the extractant and the extraction temperature and time. The content of functional groups in the humic acids is determined, and their NMR spectra are analyzed. Their ability to bind heavy metals is assessed. Their stimulation of plant growth is studied, and the biological activity of the humic acids is assessed.
48-53
Effective foaming agents for coal flotation: A quantum-chemical approach
Abstract
The effectiveness of the following compounds as foaming agents is evaluated: heteropolar ketones and sulfoxides whose molecules contain oxygen and sulfur; and petrochemical products such as butanol bottoms and T-80. The use of methylhexyl sulfoxide instead of butanol bottoms increases the extraction of the coal’s combustible component in the concentrate from 87.1–90.9% to 93.9–95.25%, with simultaneous decrease in reagent consumption by ~20%. That may be attributed to the excellent foaming properties of methylhexyl sulfoxide and its ability to render the coal particles hydrophobic. The flotational activity of compounds with different functional groups in the molecule may be compared on the basis of the energy of the hydrogen bond in molecular complexes of the reagent with the coal’s organic mass. In molecular complexes of methylhexyl sulfoxide with model compounds in the coal’s organic mass, the energy of the hydrogen bond is considerably greater than that for the corresponding molecular complexes of methylhexyl sulfoxide with model compounds in the coal’s organic mass. That ensures 35–45% increase in the adsorption of methylhexyl sulfoxide on the coal surface in comparison with methylhexyl ketone and also results in more hydrophobic coal grains, which undergo more effective flotation.
54-60
Equipment and Power Systems
Improving coke-plant efficiency by dry quenching with natural gas
Abstract
The energy efficiency of a coke plant may be increased if natural gas is used in dry quenching of the coke. The heat from the decomposition products of the natural gas is employed to boost steam generation in the waste-heat boiler. In addition, the solid carbon produced in decomposition increases the coke strength. The material and thermal balance of the dry-quenching system is calculated. A TQ diagram of the heat-transfer process in the waste-heat boiler is plotted. If dry quenching with natural gas were used for all the coke produced at a full-cycle steel plant, it would be possible to use turbines of unit power 40–65 MW. The economic benefit may be assessed in terms of the decrease in coke consumption in the blast furnace and the increased power generation thanks to utilization of the coke’s waste heat, with corresponding reduction in fuel purchases.
61-67