Influence of the ionic strength and solid/solution ratio on Ca(II)-for-Na+ exchange on montmorillonite. Part 1: Chemical measurements, thermodynamic modeling and potential implications for trace elements geochemistry

2011 ◽  
Vol 353 (1) ◽  
pp. 248-256 ◽  
Author(s):  
E. Tertre ◽  
D. Prêt ◽  
E. Ferrage
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Ionic Strength ◽  
Thermodynamic Modeling ◽  
Chemical Measurements

scholarly journals Linking environmental observations and solid solution thermodynamic modeling: the case of Ba- and Sr-rich micropearls in Lake Geneva

2017 ◽  
Vol 89 (5) ◽  
pp. 645-652 ◽  
Author(s):  
Bruno Thien ◽  
Agathe Martignier ◽  
Jean-Michel Jaquet ◽  
Montserrat Filella
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Thermodynamic Modeling ◽  
Lake Geneva ◽  
Calcium Carbonates ◽  
Lake Waters ◽  
Non Equilibrium

AbstractIntracellular inclusions of amorphous Ba- and Sr-rich calcium carbonates – referred to as “micropearls”– have recently been detected in Lake Geneva. These micropearls are formed under conditions of pronounced Ba and Sr undersaturation in the lake waters. Their formation can be explained by the ability of certain microorganisms to preconcentrate these trace elements in tandem with a non-equilibrium solid-solution growing mechanism.

Rare Earth Phosphates in the Kerch Caviar Ironstones

2021 ◽  
Author(s):  
A.V. Nekipelova ◽  
E.V. Sokol ◽  
S.N. Kokh ◽  
P.V. Khvorov
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Rare Earth ◽  
Major And Trace Elements ◽  
Environmental Risks ◽  
Solid Solution Series ◽  
Unconventional Resources ◽  
Total Budget ◽  
Low Costs ◽  
Clay Type

Abstract —The mineralogy and contents of major and trace elements (including REE+Y) in bulk samples and separate size fractions of caviar-like ironstones from the Kamysh-Burun deposit (Kerch iron province) are studied to estimate the contributions of different REE+Y species to the total budget. The analyzed ore samples contain MREE adsorbed on Fe3+-(oxy)hydroxides, as well as LREE authigenic phosphates. The predominant rhabdophane-type (Ce(PO4)⋅nH2O) phases are enriched in La, Pr, Nd, and Ca, depleted in Ce, and free from Th. The REE carriers belong to solid solution series of two main types: LREE(PO4)·nH2O – (Ca,Ce,Th)(PO4)·H2O (rhabdophane-like phase and brockite) or LREE(PO4)·nH2O – (Ca,U,Fe3+)((PO4),(SO4))·2H2O (rhabdophane-like phase and tristramite). REE phosphates occur most often in the ≤ 0.25 mm fractions of ironstones, where average and maximum ΣREE contents (Xav = 606–1954 ppm; Xmax = 769–3011 ppm) are comparable with the respective amounts in the Chinese industrial clay-type REE deposits. The Kerch ores are commercially attractive unconventional resources of highly demanded Pr and Nd: they can be extracted at relatively low costs, due to high Pr/Ce and Nd/Ce ratios, while low Th and U reduce the environmental risks from stockpiled wastes.

scholarly journals Distribution of Arsenic Inclusions in Rare Earth Steel Ingots

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 146 ◽  
Author(s):  
Hongpo Wang ◽  
Silu Jiang ◽  
Peng Yu ◽  
Bin Bai ◽  
Lifeng Sun ◽  
...  
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Rare Earth ◽  
Single Phase ◽  
Arsenic Concentration ◽  
Distribution Characteristic ◽  
Dramatic Decrease ◽  
Full Profile ◽  
Steel Ingots ◽  
Peeling Off

Trace element arsenic is detrimental to the quality and properties of steel products. We used lanthanum to modify the distribution of arsenic by the formation of arsenic rare earth inclusions and investigated all inclusions on the full profile of the ingots prepared in the laboratory. The results show that the addition of lanthanum has dramatically influenced the distribution of arsenic in the ingots by the formation of arsenic inclusions. The arsenic inclusions turn out to be mainly the cluster-shaped La-S-As, as well as its composite inclusions combined with LaS and La-As. La-S-As can be considered a solid solution of LaS and LaAs. They distribute mainly at the top surface of the ingots within 3 mm, at the side and bottom surfaces within 1.5 mm, leading to a dramatic decrease of arsenic concentration at the inner part of the ingots. This distribution characteristic of La-S-As can be used to manufacture steel ingots with very low arsenic concentration by peeling off these (La-S-As)-containing layers. On the contrary, the distribution of composite inclusions (La-S-As)-(La-As) and single-phase La-As, is uniform. Except for the reaction with arsenic, lanthanum can also react with phosphorous and antimony to modify the existing state of these trace elements.

Effects of pH, solid/solution ratio, ionic strength, and organic acids on Pb and Cd sorption on kaolinite

1991 ◽  
Vol 57-58 (1) ◽  
pp. 423-430 ◽  
Author(s):  
Robert W. Puls ◽  
Robert M. Powell ◽  
Donald Clark ◽  
Cynthia J. Eldred
Keyword(s):  
Solid Solution ◽  
Ionic Strength ◽  
Organic Acids ◽  
Effects Of Ph

The Geochemical Behaviour of Nickel in the Repository Environment

1994 ◽  
Vol 353 ◽  
Author(s):  
David Savage
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Radioactive Waste ◽  
Performance Assessment ◽  
Solid Solutions ◽  
Near Field ◽  
Solubility Data ◽  
Geochemical Behaviour ◽  
Chemical Conditions ◽  
Selection Of

Abstract59Ni may make significant contributions to calculated doses in performance assessment (PA) studies of geological repositories for radioactive waste, due principally to the adoption of relatively high near-field solubilities. Ni concentration values used in PA are typically 1–6 orders of magnitude greater than those measured in natural groundwaters. This difference is a result of the utilisation in PA of solubility data for pure nickeliferous solids, and in some instances, the selection of solids chemically incompatible with the disposal environment. The geochemical behaviour of Ni is reviewed. It is considered highly unlikely that Ni will form discrete pure solids in the repository near-field, so that partition as a trace element into solid solutions should be considered. Henry’s law behaviour of trace elements is discussed and geochemically-realistic Ni solubility values for HLW and L/ILW disposal scenarios calculated. It is concluded that Ni will behave according to the chemical conditions of the disposal environment, which should be reflected in the choice of solubility data for PA. The adoption of solid solution modelling for other elements of interest to PA should be considered.

Zur Chemie von Mischphasen in komplexen Zustandsdiagrammen Das System Bi2O3/Bi2Se3/Bi2Te3/Chemistry of Mixed Crystals in Complex Phase Diagrams The System Bi2O3/Bi2Se3/Bi2Te3

2000 ◽  
Vol 55 (7) ◽  
pp. 627-637 ◽  
Author(s):  
P. Schmidt ◽  
H. Oppermann
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Phase Diagrams ◽  
Thermodynamic Modeling ◽  
Solid Solutions ◽  
Thermodynamic Data ◽  
Phase Relations ◽  
Mixed Crystals ◽  
Complex Phase ◽  
Quaternary Solid Solution

Abstract Pseudoternary System Bi2O3/Bi2Se3/Bi2Te3, Phase Diagram, Thermodynamic Data The phase diagram of the pseudoternary system Bi2O3/Bi2Se3/Bi2Te3 is found to include a quaternary solid solution Bi2O2 (TexSe1-x) and ternary, intermetallic mixed crystals Bi2(TexSe1-x)3. Using thermodynamic modeling of the solid solutions it is possible to calcu­ late complex heterogeneous equilibria between all phases of this phase diagram. As a result we can thermodynamically describe the observed phase relations:Bi2(TexSe1-x)3 ⊿H°m(298) = 0; ⊿S°m(298) = R[xlnx + (1-x)ln(1-x)]Bi2O2(TexSe1-x) ⊿H°m(298) = Ω · x(1-x); O⊿S°m(298) = R/4 [xlnx + (1-x)ln(1-x)]Ω = 0,6 kcal/mol

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