Effect of barium and strontium ions on the morphology and polymorphism of CaCO3

Experimental Investigation of CO2‐ and Fe3O4‐Assisted Corrosion at the Cement–Casing Interface

“…The peaks at 281, 712, and 1087 cm À1 suggest the presence of CaCO 3 , which could be attributed to the cement carbonation. [62,63] The weak peaks at 532 and 667 cm À1 represent the existence of a small amount of Fe 3 O 4 , which may be the residual weighting agent Fe 3 O 4 from the cement. [64] (a) ( Figure 13 shows the XPS analysis results of the corrosion products on the surface of casing steel.…”

Crystallization of Calcium Carbonate: Modeling Thermodynamic Equilibrium, Pathway, Nucleation, Growth, Agglomeration, and Dissolution Kinetics with the Presence of Mg2+, Ba2+, and Sr2+

“…The influence of divalent metal ions on calcium carbonate precipitation is of particular importance because these ions may coprecipitate with calcium carbonates, either being adsorbed on the particle surface or forming solid solutions within many possible mechanisms and effects caused by the introduction of divalent ions in the crystalline site. ,− ,, Thus, the determination of the theoretical mode of their incorporation can be very complex, and for the sake of the model’s simplicity and applicability to the different divalent ions evaluated, an empirical linear correlation was used to represent the kinetic effects that external ions Mg 2+ , Ba 2+ , and Sr 2+ can cause on calcium carbonate precipitation (eq ). The theoretical determination of all kinetic phenomena associated with other ions would be difficult and possibly bring many parameters to the model. …”

“…Calcium carbonate is also a challenging experimental system for the study of the formation and growth of metastable phases, and their transformation as CaCO 3 has three metastable forms, amorphous calcium carbonate (ACC), crystalline monohydrate (CaCO 3 ·H 2 O), and hexahydrate (CaCO 3 ·6H 2 O), and three anhydrous forms, calcite, vaterite, and aragonite, in which calcite presents higher stability among these polymorphs under standard conditions. − Thus, investigating the kinetics and mechanisms of the processes involved in the precipitation of calcium carbonate can help to elucidate the nature and behavior of CaCO 3 metastable phases. It can also evaluate which kinetic consideration is the most important. ,, Likewise, the investigation of the influence of external ions on the kinetics and mechanisms of precipitation processes, as well as on the mode and sites of their possible incorporation into the calcium carbonate crystal lattice, contributes to the elucidation of the mechanisms of polymorphic formation. − For instance, the Mg/Ca ratio in the aqueous phase may be the driving force for the polymorphic changes in the calcium carbonate formation. ,− In addition, barium and strontium can become a natural substitute for calcium due to their similarities in properties, , although the capacity to accommodate these larger ions can vary among the polymorphs. , It has been reported that strontium can increase the abundance of aragonite and influence the performance of scale inhibitors, whereas barium ions can promote vaterite formation . Thus, it can be noted that the presence of the ions above, Mg 2+ , Ba 2+ , and Sr 2+ , can significantly affect the incrustation problem among various types of industries In particular, in the oil and gas industries where these divalent ions are commonly found in the water composition, it was observed that their presence can affect the fouling problem, as discussed by Østvold and Randhol, Graham et al, and Kamal et al…”

“…Mathematical modeling has been acknowledged as a valuable tool for simulation, optimization, and model-based control of crystallization processes. − Mathematical prediction and analysis of particle size distribution, precipitation rates, and polymorphic proportions from the experimental data available are valuable tools to enhance the comprehension of the complex phenomena behind crystallization and precipitation. ,, Furthermore, simulation studies with these mathematical models can minimize the time and material requirements compared to exclusively experimental studies as well as generate relevant information for industries that are afflicted by incrustation problems. , In addition, the simulation of the formation of the particles, characterizing both the kinetic and thermodynamic aspects of the CaCO 3 produced within the fluids produced in oil and gas industries, could be used as a virtual sensor for potential monitoring and control of incrustation problems, offering a more complete tool than the pure thermodynamic simulations that are usually used as a prediction tool by the oil and gas industry. ,, With the extensively available experimental data in the literature about the influence of divalent ions on calcium carbonate formation, one could use a thermodynamic-kinetic model to introduce the effects of these ions on the individual rates and characteristics of the carbonate solids formed. For instance, introducing the slowing down of the vaterite appearance rate that can happen with the addition of magnesium or the favoring that the strontium and barium ions can produce on the calcite and aragonite polymorph appearance. ,, …”

Effects of Tryptophan on the Polymorphic Transformation of Calcium Carbonate: Central Composite Design, Characterization, Kinetics, and Thermodynamics

“…11 To the best of our knowledge, various physicochemical factors have been found to be responsible for the polymorphic phase transformation process of CaCO 3 , such as temperature, 12 solvent type, 13 pH, 14 and initial supersaturation. 15 In addition, different additives, such as barium, strontium, and magnesium ions, 16,17 graphene oxide, 18 biocompatible polymeric additives such as bovine serum albumin and polydopamine, 19 selenic acid, arsenic acid, and silicic Polat et al: Effects of Tryptophan on the Polymorphic ... acid, 20 and various types of amino acids, 21 have been shown to greatly affect the morphology and polymorphic composition of CaCO 3 and the performance of the resulting product. CaCO 3 polymorphism has been investigated previously but more work is needed to fully understand the factors that control the structure and morphology of CaCO 3 during its polymorphic transformation.…”