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1.
Wieczorek-Ciurowa K. Gamrat K. Paryło M. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2002,70(1):165-172
The physical mixtures of hydroxocarbonates of Cu and Ni with aluminium were activated using a laboratory planetary mill. The
chemical reactions and alloy formations as the effects of grinding were followed by the phase analysis of solid products based
on the thermogravimetry and X-ray diffractometry. Experimental evidence indicates that the nature of reactions and products
of mechanical activation was dependent on the amount of aluminium and time of grinding.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Aspects of the mechanism of the overall reaction between CaCO3/CaO and SO2/SO3 under oxidizing conditions are discussed. The limestone and lime sulphation processes were carried out in a thermobalance
under conditions relevant to atmospheric fluidized bed combustion. Sulphated samples, prepared in the form of cross-section
particles, were examined in a scanning electron microscope by energy-dispersive X-ray and back-scattered electron imaging.
Photomicrographs are presented. The reaction proceeded from the outer surface of the particles and along the pores. Surface
textural changes during the reaction were considered. The layer of products was identified as controlling both the rate and
extent of limestone/lime sulphation. In the products, two sulphur-bearing solids (CaSO4 and CaS) were identified. The presence of CaS, which may cause difficulties in practice, is attributed to CaSO3 disproportionation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
K. Wieczorek-Ciurowa 《Journal of Thermal Analysis and Calorimetry》1992,38(9):2101-2107
The effects of the presence of a Pt catalyst on the limestone/lime sulphation process were investigated by thermal analysis methods to provide a better understanding of the factors limiting gas desulphurization when Ca-based sorbents are used. It was found that for the Pt-catalysed sulphation of precalcined limestone the weight increase is above 100% higher under isothermal and dynamic conditions (up to 830°C). These results are direct evidence that Pt catalyses the CaO-SO2-O2 reaction. It can be presumed that the process proceeds through a gaseous intermediate, SO3, a highly reactive gas, which explains the increased rate of sulphation. SO3 then reacts with CaO to form CaSO4 directly, in contrast with the non-catalysed oxidation of SO2 to SO3, where CaSO3 formation is the most probable early stage of sulphation. The proposed mechanisms were supported by the phase identification of the products. 相似文献
4.
K. Wieczorek-Ciurowa 《Journal of Thermal Analysis and Calorimetry》1988,33(2):407-411
Comparative data are presented on the absorption rate and capacity for SO2 capture by a natural Polish limestone with and without sodium chloride additive. Two sets of experiments were carried out, under dry and wet conditions during limestone calcination and sulphation.The presence of water vapour brought about a higher reactivity of the sorbent, probably as a result of an effect on the sintering of lime and through the influence of the CaSO4 layer. Further morphological investigations could provide confirmation of the present hypothesis.
The author would like to thank Prof. E. M. Bulewicz of this Institute for valuable discussions, and Mr. W. Balcerowiak for making available the facilities of the Laboratory of the Institute of Heavy Organic Synthesis in Kdzierzyn-Kole. 相似文献
Zusammenfassung Absorptionsgeschwindigkeit und -kapazität für SO2 an einem polnischen Kalkstein mit oder ohne NaCl-Zusatz werden verglichen. Zwei Reihen von Experimenten wurden in trockener bzw. wasserdampfhaltiger Atmosphäre bei der Calcination und Sulfatbildung durchgeführt. In Gegenwart von Wasserdampf wird die Reaktivität des Absorbens infolge Sinterung des Kalks und trotz des Einflusses der CaSO4-Schicht erhöht. Künftige morphologische Untersuchungen sollen diese Hypothese eventuel bestätigen.
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The author would like to thank Prof. E. M. Bulewicz of this Institute for valuable discussions, and Mr. W. Balcerowiak for making available the facilities of the Laboratory of the Institute of Heavy Organic Synthesis in Kdzierzyn-Kole. 相似文献
5.
A study of the kinetics of the thermal dehydration of syngenite was carried out using the isothermal gravimetric method. Weight changes of the samples were followed by means of a Mettler Thermoanalyzer. The applicability of nine equations commonly used to describe the thermal decomposition of solids was investigated. The experimental results can be best represented, over the whole temperature range of the change, by the Avrami equation I $$[ - \ln (1 - \alpha )]^{1/2} = Kt$$ whereα=degree of decomposition,t=time, andK=rate constant. The activation energy deduced for the process is 51.8±3.7 kcal·mole?1 and the log of the preexponential factor is 20.5±0.1. 相似文献
6.
Wieczorek-Ciurowa K. Gamrat K. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2003,72(1):323-328
A catalytic action of the mechanochemical products of copper hydroxocarbonate with calcium carbonate was investigated in n-butyl
alcohol oxidation tests. The solid products of high-energy milling were identified using thermogravimetry supplemented by
X-ray diffraction method. It was shown that the mechanical activation induces more effective tested catalyst because it promotes
the alcohol conversion at lower temperatures than that unmilled one.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Wieczorek-Ciurowa K. Fela K. Kozak A. J. 《Journal of Thermal Analysis and Calorimetry》2001,65(2):655-660
Attempts have been made to replace aluminium(III) by chromium(III) in the ettringite structure because of practical importance
of a waste treatment technology. The optimum conditions of Ca6[Cr(OH)6]2(SO4)3⋅26H2O formation and its thermal stability are reported.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Wieczorek-Ciurowa K. Shirokov Ju. G. Paryło M. Gamrat K. 《Journal of Thermal Analysis and Calorimetry》2001,65(2):359-366
The chemical and physical processes occurring during grinding of copper hydroxocarbonates mixtures with aluminium were studied.
A planetary ball mill was used. A thermogravimetry and X-ray powder diffraction method allowed to determine the composition
of solid products after mechanical activation. The amount of the Cu2(OH)2CO3 undecomposed andAl2O3⋅3H2O, CuO, Al2O3, Cu0, CuxAly alloys and remained Al0 in the systems is strongly dependent on the duration of grinding and on the proportion of components.
The comparative results are presented.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
K. Wieczorek-Ciurowa P. Dulian A. Nosal J. Domagała 《Journal of Thermal Analysis and Calorimetry》2010,101(2):471-477
The effect of alkaline hydrothermal activation of class-C fly ash belite cement was studied using thermal analysis (TG/DTG)
by determining the increase in the combined water during a period of hydration of 180 days. The results were compared with
those obtained for a belite cement hydrothermally activated in water. The two belite cements were fabricated via the hydrothermal-calcination
route of class-C fly ash in 1 M NaOH solution (FABC-2-N) or demineralised water (FABC-2-W). From the results, the effect of
the alkaline hydrothermal activation of belite cement (FABC-2-N) was clearly differentiated, mainly at early ages of hydration,
for which the increase in the combined water was markedly higher than that of the belite cement that was hydrothermally activated
in water. Important direct quantitative correlations were obtained among physicochemical parameters, such as the combined
water, the BET surface area, the volume of nano-pores, and macro structural engineering properties such as the compressive
mechanical strength. 相似文献
10.