Effect of heat shock on graphitization of Donbass anthracite

Abstract

The aim is to conduct experimental research into graphitization process of anthracites from the Donbass basin using shock heating, which is characteristic of furnaces with electrothermal fluidized bed. Methods. Graphitization was carried out in an electrothermal furnace at the heating rate of 1000 K/min and exposure time of 10 minutes. The temperature range of the studies was 1973-2873 K. The structure of the material was studied by X-ray diffraction and the electrical conductivity of the coal particles layer was determined using a CamScan 4DV scanning electron microscope with Link760 attachment. The changes in ash and sulfur content were determined. Findings. It was found that with an increase in the processing temperature, the interlayer distance d002 decreased from 0.350 to 0.341 nm, the ash content decreased from 3.46 to 0.4%, and the relative electrical conductivity increased by 4 times. The absolute value of anthracite graphitization degree significantly differed from the values characteristic of artificial graphite. This may be due to insufficient exposure at the studied temperatures, as well as the production of a porous, insufficiently densified coal structure during high-speed heating to 1573 K. Originality. The principal possibility of obtaining graphitized anthracite using shock heating in furnaces with electrothermal fluidized bed and the possibility of assessing anthracite graphitization degree by the value of the relative conductivity of coal particles layer are shown. Practical implications. The practical implementation of the new technology is possible after determining the optimal parameters for graphitization of anthracites, which provide a deep structural adjustment characteristic of artificial graphites. First of all, this concerns the preliminary heating of anthracite to the temperature of 1273-1373 K, as well as choosing the temperature and exposure during graphitization. Determination of these parameters will allow to evaluate the technical and economic indicators of the new technology and to adjust the design parameters of furnaces with electrothermal fluidized bed.

Evaluation of the reduction of greenhouse gas emissions when producing artificial graphite in electrothermal fluidized bed

“…Альтернативою процесу високотемпературної обробки в щільному шарі є використання печей з електротермічним киплячим шаром (ЕКШ) [6,7]. Розробка наукових основ створення цих печей та технологічних процесів з ЕКШ приходиться на 70-ті роки минулого сторіччя, але практичне їх використання було не дуже поширеним, оскільки конкурентні технології на основі щільного шару та викопного палива мали на той час свої переваги.…”

Investigation into the Effect of Multi-Component Coal Blends on Properties of Metallurgical Coke via Petrographic Analysis under Industrial Conditions

“…For the good performance of a blast furnace, coke should have high mechanical strength, be uniform in size, and have relatively low reactivity [4]. Moreover, blast furnace coke should possess a minimum of harmful components, such as moisture, mineral impurities, and sulfur [5][6][7][8][9]. Requirements for the quality of coke are being tightened due to the requirement to reduce consumption and improve blast furnaces' technical and economic performance.…”