Kinetics of Thermal Decomposition of Iron Carbonate

Abstract

HE THERMAL decomposition of iron cabonate in air was ……studied by means of DTA-TG, XRD, SEM and Mossbauer measurements. The kinetics of the thermal decomposition process were studied using isothermal and non-isothermal thermogravimetric techniques. The results show that the thermal decomposition proceeds in one step to iron oxide. Kinetic analysis of isothermal data of the decomposition reaction in the light of various solid state reaction models revealed that the reaction is best described by the diffusion models. Kinetic analysis of the dynamic TG curves were discussed with reference to Diefallah's composite integral method, in comparison with the integral methods due to Coats-Redfern and to Ozawa. The activation parameters were calculated and the results of the isothermal and dynamic integral methods which were compared to each other were discussed.Progress in an increasing number of areas of technology and hence industry is being recognized as directly related to understanding the factors influencing reactivity of solids and how they react (1) . Thermoanalytical methods have been used extensively for studying the kinetics of thermal decomposition of solids. The kinetic studies have proceeded in two directions: using powdered materials and using single crystals. The former studies are much more extensive than the latter. The essential features of solids-state decompositions are: the destruction of the crystal lattice of the reactant, the breaking and the redistribution of chemical bonds followed by the formation of the crystal lattice of the reaction product and lastly, the diffusion of one component or the other through the product layer of the propagation of the dissociation reaction. The kinetics of thermal decomposition of solids are affected by experimental factors (2) , such as heating rate, particle size, sample mass and holder design.Iron carbonate (FeCO 3 ) exists commonly in the rock (siderite core). It plays a major role in biogeochemical cycles as electron donor and acceptor in oxidationreduction reactions.

CO2 Sequestration through Mineral Carbonation: Effect of Different Parameters on Carbonation of Fe-Rich Mine Waste Materials

“…This can be observed in the figure where the largest peak (third peak) was noticeable, which indicates that this temperature interval is important because this is where the thermal decomposition of carbonate products (i.e., FeCO 3 and CaCO 3 ) occurred. This observation is in agreement with the study by El-Bellihi [53], where it has been stated that the decomposition of iron carbonate resulted in a peak at 495 • C. Stopic et al [48] also discussed the thermal decomposition of their sample and identified that a temperature interval of 470-595 • C was associated with magnesium/iron carbonate decomposition. Furthermore, Mendoza et al [47] mentioned that at 367 • C, siderite (FeCO 3 ) begins to decompose and release carbon dioxide.…”

“…Following this peak, all samples started to exhibit different peaks starting from 340 • C. At the temperature interval of 340-660 • C, the raw and carbonated samples of pH N shows a strong peak with a high weight loss disparity of 3.72% and 8.04%, respectively. On the other hand, peaks observed for pH 8-12 were at temperatures of 340-630 • C and were closely followed by another peak at around 630-700 • C. According to El-Bellihi [53] and Stopic et al [48], this can be attributed to the thermal decomposition of carbonate product, which can be seen in the temperature interval around 340-660 • C for pH N with a weight reduction of 8.04% and 340-630 • C for pH 8-12 with a weight reduction of 6.84%, 6.43% and 6.84%, respectively. A small peak around temperatures of 630-700 • C in pH 8-12 can be ascribed to the reduction of ferric oxide (Fe 2 O 3 ) or residuals from iron carbonate thermal decomposition into magnetite (Fe 3 O 4 ) [47,51].…”

“…Depending on the reaction condition, the temperature at which the carbonate product decomposes may vary or shift because of its thermal stability. Hence, the weight loss for FeCO 3 and CaCO 3 is not only subjected to a certain temperature [47][48][49][50][51][52][53][54][55][56]. For Equations ( 6) and ( 7), x is either Fe, Ca or Mg, and MW refers to molecular weight.…”

Mechanistic Insights of Dissolution and Mechanical Breakdown of FeCO3 Corrosion Films

“…In addition, FeO is often described as an intermediate product toward the transformation to Fe 3 O 4 in CO 2 environments, and therefore, it is likely that the order of formation of these corrosion products has been FeCO 3 → FeO → Fe 3 O 4 . It is worth noting that, if oxygen is present, FeO rapidly transforms to Fe 2 O 3 . − …”

Bloomery iron production in the Holy Cross Mountains (Poland) area during the Roman period: conditions during the metallurgical process and their uniformity between locations

“…However, the analyzed slags contain only up to 2.47% CaO, proving that no calcite was added as a flux. Moreover, during smelting, carbonates in the charge decompose at temperatures well below the liquidus temperature of the analyzed slags [38,39]. Isotope analyses of charcoal are also subject to errors related to the old wood effect [36].…”