scholarly journals THE SOLUBILITY OF SILVER CHLORIDE, BARIUM SULPHATE, AND CALCIUM SULPHATE AT HIGH TEMPERATURES.

1910 ◽  
Vol 32 (1) ◽  
pp. 50-66 ◽  
Author(s):  
Arthur C. Melcher
Keyword(s):  
High Temperatures ◽  
Silver Chloride ◽  
Calcium Sulphate ◽  
Barium Sulphate

Electric and phase behaviour of the solid system silver chloride - cadmium dichloride at high temperatures

1998 ◽  
Vol 30 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Alina Wojakowska ◽  
Stanisława Plińska ◽  
Jerzy Josiak ◽  
Emil Kundys
Keyword(s):  
High Temperatures ◽  
Silver Chloride ◽  
Phase Behaviour ◽  
Solid System

Infrared Spectroscopic Studies of Calcium Sulphate heated to High Temperatures

1971 ◽  
Vol 26 (7) ◽  
pp. 690-693 ◽  
Author(s):  
John Bensted ◽  
Satya Prakash Varma
Keyword(s):  
High Temperatures ◽  
Calcium Sulphate ◽  
Spectroscopic Studies ◽  
Spectroscopic Investigations ◽  
Naturally Occurring ◽  
Infrared Spectroscopic

Infrared spectroscopic investigations have shown that on the basis of changes in the ν3, SO4 band which occur when calcium sulphate is heated from 400° to 1400 °C, there are two forms of insoluble anhydrite, designated as β′- and β-CaSO4. β′-CaSO4 is metastable and is completely converted into β-CaSO4 by heating above 1000 °C. With longer heating periods this conversion can even take place at lower temperatures. β-CaSO4 is stable and is of the same type as the naturally occurring form of anhydrite.

scholarly journals Evaluating the Effectiveness of Red Onion Skin Extract Derivatives as Oilfield Scale Inhibitors

2021 ◽  
pp. 36-45
Author(s):  
Dominica Una ◽  
Dulu Appah ◽  
Amieibibama Joseph ◽  
Onyewuchi Akaranta
Keyword(s):  
Calcium Carbonate ◽  
Test Procedure ◽  
Calcium Sulphate ◽  
Barium Sulphate ◽  
Effect Of Temperature ◽  
Laboratory Evaluation ◽  
Skin Extract ◽  
Scale Inhibitor ◽  
Jar Test ◽  
Study Laboratory

With growing awareness of the environmental impact of some conventional production chemicals and concerns about the depletion of non-renewable natural resources, increased efforts are being made to use renewable and non-toxic materials in the oilfield. In this study, a potential green scale inhibitor was developed from the skin of red onions and evaluated for calcium sulphate, calcium carbonate and barium scale inhibition. Based on the different extraction processes utilized, two products were obtained and characterized using FTIR and SEM and evaluated using a static jar test procedure. The FTIR results confirmed the bands that make up the major constituents (quercetin) and other important compounds, which supports the present study. Laboratory evaluation show that ROSE can efficiently inhibit calcium sulphate scale and barium sulphate scales with a good inhibition rate of greater than 75% at an optimum dosage. Effect of temperature and dosage on inhibition performance revealed that ROSE is stable at higher temperatures and can effectively inhibit calcium and barium sulphate scales at nearly the same rate without degradation but requires additional dosage to produce same result for calcium carbonate scale. Also, the effect of time reveals that scale inhibitor performs a continuous CaSO4 and CaCO3 inhibition. Not only does ROSE perform excellently in the laboratory condition as a green scale inhibitor, but it also show a relatively close performance rate when compared to an existing commercial inhibitor which indicate that ROSE has a high potential for use in the oil industry.

scholarly journals Adsorption experiments with radium D and Radium E

1926 ◽  
Vol 111 (757) ◽  
pp. 134-143 ◽  
Keyword(s):  
Solid Solution ◽  
Active Compound ◽  
Silver Chloride ◽  
Barium Sulphate ◽  
Common Element ◽  
Active Compounds ◽  
Adsorption Effect ◽  
Solid Precipitate ◽  
The Subject ◽  
Insoluble Salt

Our knowledge of the behaviour of radio-elements in precipitation reactions is mainly due to Fajans and his co-workers, who investigated the relation existing between the completeness of the removal of the radio-element from solution and the solubility of its salt. They found that, when a filterable quantity of the precipitate of a common element was brought down in a solution containing an infinitesimal quantity of a radio-element, the radio-element itself was precipitated, if its corresponding compound was also insoluble. This general conclusion was later investigated by Fajans and Richter ( loc. cit .) with respect to thorium B, and it was further established that the degree of removal of the radio-element was dependent on the solubility of the precipitate of the ordinary element. Thus with very insoluble precipitates such as bismuth sulphide and barium sulphate, thorium B was completely precipitated, while less insoluble precipitates like silver chloride carried down only part of the radio-element. It was also suggested that when the precipitate was the insoluble salt of an isotope, the removal of the radio-element was to be ascribed to its solid solution in the isotopic precipitate, whereas removal by precipitates of dissimilar elements was an adsorption effect. This last fact, the connection between the adsorption of radio-elements by various substances and the solubility of the corresponding active compounds, was the subject of detailed researches by Paneth, and by Horovitz and Paneth. As a result, it was proved that the connection between the magnitude of the completeness of removal of the radio-element and the solubility of the analogous radio-active compound, held for a solid precipitate added to the solution as well as for the case of a precipitate brought down in the solution. Experiments have also been conducted in this field by Ebler and van Rhyn and others.

Understanding the Co-deposition of Calcium Sulphate and Barium Sulphate and Developing Environmental Acceptable Scale Inhibitors Applied in HTHP Wells

2012 ◽  
Author(s):  
Xuan Liu ◽  
Tao Chen ◽  
Ping Chen ◽  
Harry Montgomerie ◽  
Thomas Hille Hagen ◽  
...  
Keyword(s):  
Calcium Sulphate ◽  
Barium Sulphate

Investigation of BaSO4-KPO3-Na2B4O7 Low-Melting Glass System as a Basis for Synthesis of a Glass-Solder Material

2021 ◽  
Vol 887 ◽  
pp. 60-64
Author(s):  
Alexey Stolbovsky ◽  
Vita Vyatchina
Keyword(s):  
Glass Formation ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Softening Temperature ◽  
Calcium Sulphate ◽  
Barium Sulphate ◽  
Glass Formation Region ◽  
Concentration Triangle ◽  
Formation Region ◽  
Concentration Dependences

The possibility of using the compositions of BaSO4-KPO3-Na2B4O7 system as a glass-solder (frit) material was shown. A glass formation region has been established in BaSO4-KPO3-Na2B4O7 system which is located in the borate-phosphate part of the concentration triangle and occupies ~41% of the triangle area. The concentration dependences of linear thermal expansion coefficient (TCLE), the softening temperature and the glass transition temperature was determined and discussed. It is established that the glass formation region, the concentration dependences of TCLE and technological temperatures values are significantly closer to those for CaSO4-KPO3-Na2B4O7 system than for MgSO4-KPO3-Na2B4O7 system. That may point out at the similar effect barium sulphate and calcium sulphate doping in the sulphate-phosphate-borate systems.

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

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