scholarly journals Formation and Aging of Precipitates. XII. Studies on Types of Crystal Growth of Barium Sulfate by Dissolution in Water

1959 ◽  
Vol 32 (5) ◽  
pp. 442-445 ◽  
Author(s):  
Kazuyoshi Takiyama
Keyword(s):  
Crystal Growth ◽  
Barium Sulfate

Crystal Growth and Dissolution of Barium Sulfate

1975 ◽  
Vol 15 (06) ◽  
pp. 509-516 ◽  
Author(s):  
G.H. Nancollas ◽  
S.T. Liu
Keyword(s):  
Crystal Growth ◽  
Crystal Lattice ◽  
Barium Sulfate ◽  
Scale Formation ◽  
Dissolution Process ◽  
Equilibrium Solubility ◽  
Precipitation Reactions ◽  
Solubility Products ◽  
Precipitated Phases ◽  
Made In

Abstract The kinetics of crystallization and dissolution of barium sulfate seed crystals were investigated conductimetrically. Growth is characterized by an initial surge caused by secondary nucleation, followed by a rate that is proportional to The square of the supersaturation. Studies were made using seed material of differing morphology; in all cases, the crystallization was surface controlled. A surface reaction also appears to be rate-determining for the corresponding dissolution process, but the over-all rate constant is considerably greater than that for growth. Crystallization and dissolution were studied in the presence of potential phosphonate and polyphosphate scaling inhibitors phosphonate and polyphosphate scaling inhibitors in some cases, both processes were markedly inhibited. The incorporation of the antiscalant into the developing crystals may pose problems in down-hole application. Introduction The state of knowledge of adsorption and desorption phenomena and of reactions at the solid-liquid interfaces under wellbore conditions is extremely limited. Consequently, the procedures used for eliminating scale by the chemical treatment of surface waters that are frequently injected into an oil-bearing formation are often based on empirical considerations. In the absence of knowledge of the mechanism of scale formation and its inhibition, the choice of additive is usually made on the basis of the results of spontaneous precipitation experiments made in the laboratory. precipitation experiments made in the laboratory. Although attempts are made to reproduce such experimental data, extreme sensitivity to factors such as the methods used to mix reagents, rates of stirring, and concentrations of reactants make it impossible to do so. Also, it is difficult to avoid heterogeneous nucleation in such systems, and this process also may be influenced by the presence of the additive. Interpretations of the course of the precipitation reactions solely in terms of the precipitation reactions solely in terms of the thermodynamic solubility products of the precipitating minerals also is questionable. Such precipitating minerals also is questionable. Such treatments assume that, at all stages of the scaling process, the systems are effectively at equilibrium process, the systems are effectively at equilibrium and are amenable to treatment using experimental solubility products. It has been shown that kinetic factors often are considerably more important in determining the course of a precipitation process. Thus, in the case of calcium phosphate crystal growth, an amorphous precursor is formed rapidly at the beginning of the reaction and undergoes a slow transformation to the thermodynamically stable phase, hydroxyapatite. Significant changes with phase, hydroxyapatite. Significant changes with time are observed in such factors as chemical composition, crystallinity, and the specific surface areas of the solid phases. The nature of the initially precipitated phases and the course of the subsequent precipitated phases and the course of the subsequent crystal growth reaction is markedly dependent not only on the degree of supersaturation of the solution, but also on the ionic strength of the solution and the type of neutral or inert electrolyte present. Simple equilibrium solubility studies reveal nothing of these factors that may be important in determining whether scale will form in the field. Not only is the growth of crystals important for studies of scale formation, but a knowledge of the mechanism of the reverse process, dissolution, also is essential if the results of laboratory experiments are to be used to predict the behavior in actual scaling situations. At first, the growth and dissolution of crystals may be considered to be exactly reciprocal processes. The dissolution process usually has been considered to be a simple process usually has been considered to be a simple diffusion-controlled process, with the transport of lattice ions away from the crystal surface as the slow step in the reaction. in terms of diffusion following Fick's law, the rate of reaction would be expected to be proportional to the subsaturation, mo - m, where m is the molar concentration of electrolyte in the solution and mo is the equilibrium (solubility) value. Although a number of salts follow this kinetic path, there is now appreciable evidence that the dissolution of many slightly soluble salts is controlled by a process other than film diffusion of the crystal lattice ions. Whereas scale inhibitors would be expected to have little influence on a dissolution process that depends on the diffusion of crystal lattice ions away from the surface, a surface-controlled process may be markedly retarded in their presence. SPEJ P. 509

Alginate Operates as a Dual Inhibitor of Barite Nucleation and Crystal Growth

2021 ◽  
Author(s):  
Xi Geng ◽  
Ricardo D. Sosa ◽  
Michael Reynolds ◽  
Jacinta C. Conrad ◽  
Jeffrey D Rimer
Keyword(s):  
Crystal Growth ◽  
Barium Sulfate ◽  
Potent Inhibitor ◽  
Dual Inhibitor ◽  
Common Scale

Few (macro)molecular inhibitors of inorganic scale can suppress both nucleation and crystal growth. In this study, we identify a potent inhibitor of barium sulfate (barite), which is a common scale...

scholarly journals Using Molecular Modelling to Understand and Predict the Impact of Organic Additives as Crystal Growth Modifiers

2020 ◽  
Vol 73 (8) ◽  
pp. 724 ◽  
Author(s):  
Franca Jones ◽  
Andrew L. Rohl
Keyword(s):  
Crystal Growth ◽  
Molecular Modelling ◽  
Barium Sulfate ◽  
Organic Molecules ◽  
Adsorption Process ◽  
Organic Additives ◽  
Lattice Matching ◽  
Growth Modification ◽  
Matching Criteria ◽  
The Impact

Empirical molecular modelling was used to investigate the impact of organic additives on crystal morphology and inhibition. The replacement energy was found to correlate reasonably well with the degree of inhibition as determined from conductivity data. The replacement energy was also able to predict the barium sulfate face on which additive adsorption was most likely. While the ability of the organic functional groups to sit in the vacant sulfate lattice positions (the so-called ‘lattice matching’ criteria) appears intuitively sensible, it was found that this is not a sufficient criterion to predict real behaviour. A better criterion is the overall replacement energy as it takes into consideration the number of Ba–Oorganic interactions and whether the adsorption process overall is energetically favourable (by including the hydration energy of the ions). Thus, the replacement energy can successfully predict the effect of organic molecules on the crystal growth modification of barium sulfate.

Nucleation and crystal growth of barium sulfate: inhibition in the presence of rigid and flexible triphosphonate additives

CrystEngComm ◽  
2018 ◽  
Vol 20 (41) ◽  
pp. 6589-6601 ◽  
Author(s):  
Evangelos D. Athanasopoulos ◽  
Eirini Armakola ◽  
Petros G. Koutsoukos ◽  
Konstantinos D. Demadis
Keyword(s):  
Crystal Growth ◽  
Barium Sulfate

The influence of two triphosphonate additives (flexible and rigid) on the crystallization of barite has been evaluated.

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