The Solubility of Some Alkali-Bearing Zr Minerals in Hydrothermal Solutions

1996 ◽  
Vol 432 ◽  
Author(s):  
S. U. Aja ◽  
S. A. Wood ◽  
A. E. Williams-Jones
Keyword(s):  
Hydrothermal Solutions ◽  
Mineralization Process ◽  
Two Stage ◽  
Calculated Phase ◽  
Crustal Fluids ◽  
Hydrothermal Mineralization ◽  
Solubility Products ◽  
Phase Relationships

AbstractThe hydrolytic dissolution of some Zr-bearing minerals has been measured in aqueous KCl and KF solutions. Depending on the mineral being investigated, Zr concentrations varied from about 9 ppb to nearly 40 ppm in equilibrated solutions; this validates the notion of Zr mobility in some crustal fluids. At 50 °C, ΔfG were determined (using the measured solubility products) for Na catapleiite, elpidite, vlasovite and weloganite to be -4654.2±5.6, -7391.0±11.6, -5181.0±7.3 and -7130.5±1.0 kJ/mol, respectively. Calculated phase relationships amongst the zirconosilicates found at the Strange Lake peralkaline complex indicate that elpidite and gittinsite cannot coexist stably implying a two-stage hydrothermal mineralization process.

scholarly journals HYDROTERMÁLNÍ MINERALIZACE V HORNINÁCH SOLÁŇSKÉHO SOUVRSTVÍ V ZÁPADNÍ ČÁSTI CHŘIBŮ

2016 ◽  
Vol 23 (1-2) ◽  
Author(s):  
Jana Vlasáková ◽  
Kamil Kropáč
Keyword(s):  
Sedimentary Rocks ◽  
Northwestern Part ◽  
Hydrothermal Solutions ◽  
Migration Activity ◽  
Alpine Orogeny ◽  
Low Salinity ◽  
Hydrothermal Mineralization ◽  
Tectonic Events ◽  
Higher Hydrocarbons ◽  
The Town

Hydrothermal mineralization sporadically occurs in the western part of Chřiby Hills in a form of thin carbonate veins and veinlets hosted by sedimentary rocks of the Lukov Member of the Soláň Formation. These veins were found in old quarries and slope debris nearby Koryčany, Cetechovice, and Roštín. The mineral filling of studied veins is formed by calcite or rarely calcite and barite. Based on the investigation of fluid inclusions, hydrothermal calcite crystallized from low-temperature (Th = 70–187 °C) and on average low-salinity (0.2–5.6 wt. % NaCl equiv.) hydrothermal solutions. Hydrothermal veins filling crack systems with the direction NNW–SSE or W–E in quarries Holý kopec near Koryčany and Roštín-Chapel are probably post-tectonic. Their origin can be connected to young tectonic events after the termination of main phase of the Alpine Orogeny. Diagenetic origin cannot be excluded in case of calcite vein which fills a bed joint between layers of conglomerate in old quarry 3.5 km south–southeast from the town Koryčany. The source fluids can be derived from mixing of seawater with diagenetic waters. In case of post-tectonic veins, a contribution of meteoric waters is also possible. In addition, UV-fluorescence microscopy reveals a sporadic presence of inclusion with higher hydrocarbons which exhibits strong blue-white fluorescence. These inclusions document a migration activity of higher hydrocarbons in the northwestern part of the Rača Unit in Chřiby Hills.

Two-stage self-seeding method for preparation of single crystals of poly(phenylene sulfide)

1989 ◽  
Vol 47 ◽  
pp. 368-369
Author(s):  
Sengshiu Chung ◽  
Peggy Cebe
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Dilute Solution ◽  
Two Stage ◽  
Annealing Behavior ◽  
High Performance Polymers ◽  
Seeding Method ◽  
Phenylene Sulfide

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.

364: Two stage "Progressive Elongation of Spermatic Cord" Technique in Criptorchidism with very short Spermatic Vessels

2007 ◽  
Vol 177 (4S) ◽  
pp. 121-121
Author(s):  
Antonio Dessanti ◽  
Diego Falchetti ◽  
Marco Iannuccelli ◽  
Susanna Milianti ◽  
Gian P. Strusi ◽  
...  
Keyword(s):  
Spermatic Cord ◽  
Two Stage

360: A Contemporary Analysis of Two-Stage Hypospadias Repair

2007 ◽  
Vol 177 (4S) ◽  
pp. 120-120
Author(s):  
Pamela I. Ellsworth ◽  
Anthony Caldamone
Keyword(s):  
Hypospadias Repair ◽  
Two Stage

Two-Stage Gastric Surgery Urged for Superobese

2005 ◽  
Vol 38 (18) ◽  
pp. 68
Author(s):  
SHARON WORCESTER
Keyword(s):  
Gastric Surgery ◽  
Two Stage
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