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The effect of end temperature on coke qualities
01 Solid fuels (derived solid fuels) or pseudographite-like structures were formed through further acid catalysed reaction. The two types of coke could be combusted at 300 and 600”. respectively. The results may be used to choose operation parameters to restore initial activity of the coked catalysts. 02/00783 Coke dispersion in carbon-mineral porous adsorbents Mel’gunov, M.S. er al. Curbon, 2001, 39, (3), 357-367. The morphology, dispersion and localization of coke in coked alumina and silica have been investigated by a newly developed technique, which can be applied generally for studies of other systems of ‘support+modifier’ type. It is shown that, at the considered amounts of coke, deposited coke clusters partially cover the surface of silica leading to a mosaic-like structure of the resulting carbon-mineral material surface. These clusters are predominantly located in the pores of silica gel. Probably the pores filled with coke are formed by the tetrahedron packed SiOz globules. On the other hand, the intensity of coke formation on the alumina surface is considerably higher then on the silica surface, so coke formation is accompanied by the total surface coverage at low amounts of coke deposited. Possible reasons for these differences are considered. 02iOO784 Coke quality requirements for blast furnaces Cheng, A. Iron S~eelmrrker, 2001, 28, (3), 3940. Various quality parameters and their effect on blast furnace performance, mostly in terms of their impact on coke rate (i.e. coke rate coefficients) are discussed. 02/00785 Criteria for evaluation of the quality of blastfurnace coke. Prospects for its improvement in the IspatKarmet Public Joint-Stock Company Pluzhnikov, A.I. ef crl. Koks K/Tim., 2001, I, 8-10. (In Russian) Blast furnace coke is evaluated by determining its reactivity for carbon dioxide (1100” for 2 h), followed by determination of the mechanical strength of the residue. 02lOO788 DSC study of curing in smokeless briquetting Mayoral, M.C. T/iermochim. Actor, 2001, 371, (l-2), 41-44. Briquettes potentially suited for smokeless fuel were successfully prepared from mixtures of previously pyrolysed coal and biomass, and mixed with sugar cane molasses as binder. Briquettes were cured at 200°C in air for different times, and the quality of the cured briquettes was assessed using the water and impact resistance tests (WRI and IRI). Since curing was an exothermic process, the residual heat of reaction evolved was considered to be an indication of the degree of curing. In this work, the degree of curing as a function of time was monitored quantitatively, measuring the residual heat of reaction at each condition studied by differential scanning calorimetry (DSC), and compared with the physical characterization. The results implied that the technique did not give a fast alternative to WRI and IRI tests, but was very useful in describing the mechanism by which the molasses behaved as binders. 02/00787 Effect of coal ranks on quality of formed coke Wang, Y. ef al. Mrirm Z/tuunhua, 2001, 24, (I). 66-70. (In Chinese) The paper introduces the technology of producing formed coke with high quality using fine anthracite with cold briquetting process. The coking tests of five kinds of anthracites with different ranks were made. The regulation and mechanism of changes of formed coke qualities determined by coal ranks were proposed. The qualities and benefits of formed cokes produced using anthracites with different ranks were evaluated. 02/00788 Formation of polycyclic aromatic hydrocarbons coincident with pyrolytic carbon deposition Glasier, G.F. ef rrl. C&on, 2001, 39, (4), 497-506. Ethane was pyrolysed in a flow reactor system at residence times from 0.5 to 20 s, at 1185 K and a pressure of 40 kPa. Liquid products were trapped and analysed by liquid chromatography, gas chromatography and mass spectrometry using atmospheric pressure chemical ionization and electron impact ionization. At least 90 products (with M/Z ratios up to 700) were present; of these products I9 were identified, and eight were quantified. Benzene was the major liquid product, with a maximum yield of 16% by weight of the feed gas. Products with even numbers of carbon atoms were prominent, which is consistent with theories proposing that PAHs grow by the addition of acetylene. Most of the aromatics quantified had maximum yields at about 6 s, coinciding with the maximum rate of carbon deposition in the reactor, as recorded by a micro-balance. This observation is consistent with theories proposing that pyrolytic carbon is formed from aromatics. 02/00789 Manufacture of coal briquets Zakrzewski, Z. el ~1. Pol. PL 178,672 (Cl. CIOL5/14), Appl. 310,268, I Sep 1995. 3. (In Poland) 98
Fuel and Energy Abstracts
March 2002
31 May 2000.
Manufacturer of coal briquettes involves (1) mixing of coal fines (particle size ~6 mm) with 4-10% binder consisting of a (l-3):(1-3) mixture of starch and molasses and O.l-0.5% hardener consisting of 86% HsP04 and/or AI-K sulfate, (2) conventional briquetting, and (3) two-stage thermal treatment including drying at 595” to obtain a water content of ~2% and hardening for 0.5-1.5 h at 120-200”. Resulting briquettes have a high strength, are mold-resistant, and do not disintegrate in water.
02/00790 Manufacture of metallurgical coke Fukada, K. e/ crl. Jpn. Kokai Tokkyo Koho JP 2001 115,168 (Cl. CIOB57/04), 24 Apr 2001, Appl. 1999/296,154, I9 Ott 1999. 8. (In Japanese) The coke is prepared by dry distillation of a mixture of coal, a binder, and an inert additive in a coke oven; where the binder is added at an amount o controlled by the particle size distribution P or Q of the inert additive and the amount of the additive C, for satisfying the target hardness and particle size of the coke.
02/00791 Method for operation of coke oven with improved response toward fluctuation Ogata, Y. PI u/. Jpn. Kokai Tokkyo Koho JP 2001 72,981 (Cl. CIOBS7; OO), 21 Mar 2001, Appl. 1999/249,523, 3 Sep 1999. 5. (In Japanese) The method is carried out by increasing (or decreasing) residence time of coke oven without change oven temperature, then increasing (or decreasing) carbonization time with lowering (raising) oven temperature and shortening (lengthening) idle time, during operation toward low (or high) load.
02/00792 Possibilities of automated IR spectral analysis of coal charges for prediction of coke quality Zhilyaev, Yu. A. e/ ul. Koks Khim., 2001, I, 2-6. (In Russian) Analysis of coals and coking charges is carried out using an automated IR spectral method determining 25 indexes (as alternative indexes to those of standardized ones) and 40 IR-spectral characteristics (from one sample, by one analyst, and with one apparatus). During the analysis of a series of samples, computer results are printed every 45 min for each subsequent sample, showing the 25 alternative indexes of charges quality, four indexes of coke quality, and the amount of coke needed for 1 t of cast iron.
02100793 Preparation of coal-derived needle coke Wei, G. et cl/. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,268,544 (Cl. CIOB53/06), 4 Ott 2000, Appl. 2,000,l 15,132. 24 Mar 2000, 9. (In Chinese) The process comprises heating coal asphalt, removing impurity, by twostage vacuum flash vaporization to obtain purified raw maternal; with byproduct of impregnant and binder, compression and pre-carbonization to obtain refined material, carbonization of the refined material to obtain coke, then calcining at 1450f550”, crushing, and screening to obtain needle coke. The coal asphalt can be substituted by shale oil, heavy fraction of petroleum, coal tar, etc. The process improves the product quality.
02100794 Reactivity of coal cokes. Zvyagintseva, E.V. and Skripchenko, G.B. Khim. Tvercl. Top/. ~Moscow), 2000, 6, 61-72. (In Russian) Oxidation reactivity (to air oxygen) of cokes obtained from individual coals and multicomponent charges was studied by thermogravimetry. The study included effects of coal rank, premolding (press), and coking additives. An attempt was made to correlate the reactivity with structural characteristics, specific surface area, and COa reactivity.
02100795 The effect of end temperature on coke qualities Yoon, K-H. et crl. RIST Yongu Nonmun, 2000, 14, (4). 429.-433 (In Korean) This study was performed to investigate the relationship between the coke end-temperature and coke quality by blending 20 kg low cost coal in the range of 15-40 wt%. Increasing the coke end temperature did not necessarily improve the coke quality at constant mixing ratios of low cost coal. Both inner pore of coke, produced by rapid evaporation of volatile matter caused by fast coking rate, and the thermal stress in high temperature resulted in deterioration in coke quality. There was the range of coke end-temperature in which coke quality became maximized. As ratios of low cost coal increased, coke quality decreased and the range of coke end-temperature in which coke quality became maximized transferred to higher temperature. These observations could be explained in terms of coke heat quantity and coal midtemperature.
Fuel and Energy Abstracts
March 2002
31 May 2000.
Manufacturer of coal briquettes involves (1) mixing of coal fines (particle size ~6 mm) with 4-10% binder consisting of a (l-3):(1-3) mixture of starch and molasses and O.l-0.5% hardener consisting of 86% HsP04 and/or AI-K sulfate, (2) conventional briquetting, and (3) two-stage thermal treatment including drying at 595” to obtain a water content of ~2% and hardening for 0.5-1.5 h at 120-200”. Resulting briquettes have a high strength, are mold-resistant, and do not disintegrate in water.
02/00790 Manufacture of metallurgical coke Fukada, K. e/ crl. Jpn. Kokai Tokkyo Koho JP 2001 115,168 (Cl. CIOB57/04), 24 Apr 2001, Appl. 1999/296,154, I9 Ott 1999. 8. (In Japanese) The coke is prepared by dry distillation of a mixture of coal, a binder, and an inert additive in a coke oven; where the binder is added at an amount o controlled by the particle size distribution P or Q of the inert additive and the amount of the additive C, for satisfying the target hardness and particle size of the coke.
02/00791 Method for operation of coke oven with improved response toward fluctuation Ogata, Y. PI u/. Jpn. Kokai Tokkyo Koho JP 2001 72,981 (Cl. CIOBS7; OO), 21 Mar 2001, Appl. 1999/249,523, 3 Sep 1999. 5. (In Japanese) The method is carried out by increasing (or decreasing) residence time of coke oven without change oven temperature, then increasing (or decreasing) carbonization time with lowering (raising) oven temperature and shortening (lengthening) idle time, during operation toward low (or high) load.
02/00792 Possibilities of automated IR spectral analysis of coal charges for prediction of coke quality Zhilyaev, Yu. A. e/ ul. Koks Khim., 2001, I, 2-6. (In Russian) Analysis of coals and coking charges is carried out using an automated IR spectral method determining 25 indexes (as alternative indexes to those of standardized ones) and 40 IR-spectral characteristics (from one sample, by one analyst, and with one apparatus). During the analysis of a series of samples, computer results are printed every 45 min for each subsequent sample, showing the 25 alternative indexes of charges quality, four indexes of coke quality, and the amount of coke needed for 1 t of cast iron.
02100793 Preparation of coal-derived needle coke Wei, G. et cl/. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,268,544 (Cl. CIOB53/06), 4 Ott 2000, Appl. 2,000,l 15,132. 24 Mar 2000, 9. (In Chinese) The process comprises heating coal asphalt, removing impurity, by twostage vacuum flash vaporization to obtain purified raw maternal; with byproduct of impregnant and binder, compression and pre-carbonization to obtain refined material, carbonization of the refined material to obtain coke, then calcining at 1450f550”, crushing, and screening to obtain needle coke. The coal asphalt can be substituted by shale oil, heavy fraction of petroleum, coal tar, etc. The process improves the product quality.
02100794 Reactivity of coal cokes. Zvyagintseva, E.V. and Skripchenko, G.B. Khim. Tvercl. Top/. ~Moscow), 2000, 6, 61-72. (In Russian) Oxidation reactivity (to air oxygen) of cokes obtained from individual coals and multicomponent charges was studied by thermogravimetry. The study included effects of coal rank, premolding (press), and coking additives. An attempt was made to correlate the reactivity with structural characteristics, specific surface area, and COa reactivity.
02100795 The effect of end temperature on coke qualities Yoon, K-H. et crl. RIST Yongu Nonmun, 2000, 14, (4). 429.-433 (In Korean) This study was performed to investigate the relationship between the coke end-temperature and coke quality by blending 20 kg low cost coal in the range of 15-40 wt%. Increasing the coke end temperature did not necessarily improve the coke quality at constant mixing ratios of low cost coal. Both inner pore of coke, produced by rapid evaporation of volatile matter caused by fast coking rate, and the thermal stress in high temperature resulted in deterioration in coke quality. There was the range of coke end-temperature in which coke quality became maximized. As ratios of low cost coal increased, coke quality decreased and the range of coke end-temperature in which coke quality became maximized transferred to higher temperature. These observations could be explained in terms of coke heat quantity and coal midtemperature.