ISSN 1068-364X, Coke and Chemistry, 2009, Vol. 52, No. 2, pp. 77–82. © Allerton Press, Inc., 2009. Original Russian Text © D.V. Miroshnichenko, 2009, published in Koks i Khimiya, 2009, No. 2, pp. 37–42. 77 Ukrainian coal reserves permits the production of only a limited quantity of coke with the required reac- tivity CRI and postreactive strength CSR: no more than 3.8–4.0 million t [1]. Such coke may only be produced from coal produced at three Ukrainian mines: South Donetsk Basin mine 3 (coal of rank G); Skochinskii mine (rank Zh); and Krasnoarmeiskaya Zapadnaya No. 1 mine (rank K). This means that technological fac- tors capable of improving the high-temperature proper- ties of coke are of particular importance [2–5]. In the present work, we consider the influence of some of these factors. GRINDING OF THE BATCH To investigate the influence of batch grinding on the coke reactivity, production batches from nine Ukrainian coke plants are coked in a laboratory furnace designed by the Coal-Chemistry Institute (CCI) [6]. The batch is coked in the form used at the original plant and also after grinding until it consists up to 100% entirely of the ≤3 mm class. Table 1 presents, in general form, the change in coke properties per 1% increase in the content of the ≤3 mm class in the batch (Σ3–0, %). Analysis of the results indicates that fine grinding increases the cold strength Π 25 and hot strength TMS [7] and the actual density and decreases the wear (W 10 ) and the reactivity (RC) of the coke. In other words, the overall coke quality is improved. Experimental coking of the same batch in the same furnace when the content of the ≤3 mm class is 87.5%, 94%, and 100% yields coke with CRI = 46.1%, 48.1%, and 50.4% and CSR = 28.5%, 24.8%, and 25.0%, d r d respectively. In other words, the coke quality tends to decline in terms of CRI and CSR. However, the results differ from the mean CRI (48.2%) and CSR (26.1%) by no more than the permis- sible error of parallel measurements (3.5% when CSR = 30–50% and CRI = 40–60%) [8]. Therefore, the influ- ence of batch grinding on CRI and CSR cannot be regarded as conclusive. Nevertheless, we should note that selective grinding of the batch in the range from 82% to 88% of the ≤3.35 mm class at the Port Campbell plant (Australia) improved both the cold strength and hot strength of the coke (to CSR = 74.1% and CRI = 17.1%) [9]. In our view, these excellent results are due not so much to the grind- ing of the batch as to the very low total sulfur content of the batch ( = 0.42%), associated with the low content of sulfide in the coke; sulfur in sulfide form is known to S t d COKE Influence of Coal Preparation and Coking Conditions on Coke Reactivity D. V. Miroshnichenko Ukrainian State Coal-Chemistry Institute, Kharkov, Ukraine e-mail: yo@ukhin.ua Received November 12, 2008 Abstract—The influence of various technological factors on the high-temperature properties of coke is inves- tigated. It is found that factors facilitating an orderly organic structure of the coke (fine grinding and compaction of the batch, increased conditioning of the coke, dry slaking, the introduction of lubricant additives in the batch) reduce the reactivity of the coke; by contrast, introducing coke fines, intermediate product, and red mud in the batch increases the reactivity. DOI: 10.3103/S1068364X09020069 Table 1 Coke characteristic Symbol, dimensions ΔΠ i,k /1 % Σ3–0 Resistance to grinding Π 25 , % +(0.04–0.09) Wear W 10 , % –(0.02–0.08) Actual density g/cm 3 +(0.003–0.007) Reactivity (GOST 10089–89) K m , cm 3 /g s –(0.002–0.005) Reactivity (CCI) RS, % –(0.17–0.40) Thermomechanical strength (CCI) TMS, % +(0.28–0.37) d r d ,