Zbykovskyy Y. Scientific and theoretical bases for development of resource-saving technology for complex energy-chemical and technological processing of coal in the coke-chemical production

The dissertation is devoted to the solution of an important problem of coke and chemical production  development of the scientific bases of the complex resource- and energy- saving environmentally friendly technology of the coke chemical production which includes the following technologies: production of smokeless solid fuel, gasification of smokeless solid fuel with obtaining of the synthesis gas, partial briquetting of coal mixture before the coking, coke processing outside the oven with an aqueous solution of potassium pentaborate. The concept of resource-saving technology of energy-chemical and technological processing of coal on the basis of ecological approach was further developed. The possibility of creating a flexible complex technology that will allow to diversify coke and chemical production without its radical reconstruction has been established. Ideas about the main features of energy-chemical and technological processing of low-sulfur low-metamorphosed high-ash coal were developed. These include: formation of new thermotechnical properties of artificial energy fuel and improvement of its kinetic and dynamic combustion characteristics. New ideas about the kinetics and dynamics of smokeless solid fuel combustion have been obtained. The ability of smokeless solid fuel during combustion in the medium temperature range (up to 5600C) to react with oxygen in the initial conversion stage (X=6-8%) in the kinetic phase at a rate higher (maximum specific carbon burning rate Rm04,2∙10-4 1/s) compared to highly metamorphosed fuels was established. The ability of smokeless solid fuels in the high temperature zone (more than 8000C) to transform the combustion to the external diffusion phase has been proved. It is established that its speed is increasing (duration of burn-out  400 s) in the process of high temperature combustion and the processes in industrial power plants are intensified. The technological conditions for realization of the process of briquetting of coal mixture with individual multicomponent binder formed from liquid waste of coke and chemical production was substantiated. The parameters of the briquetting process have been established and experimentally confirmed: the moisture content of the briquetting coal (coal mixture) should be less than 8%, the amount of binder  10-15%, the mixing temperature of the mixture of coal and binder  50-800C, pressure pressing  50-70 MPa, briquette structuring time at 140-1600C  one hour or holding time at 15-250C  3-5 days. The possibility of the complete utilization of liquid wastes of coke and chemical production by the method of their use in technology of partial briquetting of coal mixture before coking as a complex binder (67% of fuses, 30% of acidic tar, 3% of polymers) in the amount of 10-15% was proved. The ability of a multicomponent carbonaceous binder to engage in adhesive processes with the solid phase of the coal mixture was proved. This ensures the strength of the briquettes at the stage of structuring. A mathematical model of the process of briquetting coal mixture with an individual and multi-component binder formed from liquid waste of coke and chemical production has been developed. The interaction of borates of alkali metal with the surface of blast-furnace coke pieces during the outside oven process with the use of an aqueous solution of potassium pentaborate KB5O8 (content of dry pentaborate in coke  up to 0.68 wt.%, nonionogenic surface-active substance  up to 0.0070 wt. %) was investigated. The possibility of creating a reliable protective layer on the pieces of coke which inhibits the reaction of carbon coke with oxygen and carbon dioxide in the blast furnace was provided. It provides an opportunity to improve the quality of coke to the level of international standards: CRI ≤ 22-25% and CSR ≥ 65-70%. The peculiarities and nature of changes of the coke quality indicators and the decrease in the reactivity of blast furnace coke and the increase of the post-reaction strength after the endurance in time of coke which was treated with an aqueous solution of potassium pentaborate with the addition of surface-active substance were investigated. Factors which impact on the CSR and CRI indexes of coke have been identified. These include reducing the specific surface area of coke available to oxidizing gases, increasing the surface of coke crystallites covered with a protective layer of B2O4-2 dimeric anions as well as an increase in the number of K+ ions that intercalate into the porous carbon structure of coke. Keywords: resource-saving technology, coke production, smokeless solid fuel, coke processing outside the oven, gasification, briquetting, waste disposal.