Complete removal of trace vanadium from ammonium tungstate solutions by solvent extraction

2018 ◽  
Vol 179 ◽  
pp. 268-273 ◽  
Author(s):  
Liupei Wang ◽  
Guiqing Zhang ◽  
Wenjuan Guan ◽  
Li Zeng ◽  
Qin Zhou ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Complete Removal ◽  
Ammonium Tungstate

Defect Analysis of 316LSS during the Powder Injection Moulding Process

2012 ◽  
Vol 329 ◽  
pp. 35-43 ◽  
Author(s):  
M. Rafi Raza ◽  
Faiz Ahmad ◽  
M.A. Omar ◽  
R.M. German ◽  
Ali S. Muhsan
Keyword(s):  
Solvent Extraction ◽  
Complete Removal ◽  
Processing Parameters ◽  
Powder Injection ◽  
Extraction Temperature ◽  
Heating Rates ◽  
Process Step ◽  
Moulding Process ◽  
Aerospace Applications ◽  
Injection Moulding Process

Austenitic Stainless Steel Has a FCC Structure at Room Temperature and the Temperature Range of the Austenite Phase Depends upon its Composition. 316L SS Is Widely Used in Medical, Marine, Industrial, Sporting and Aerospace Applications due to its Excellent Combination of Mechanical Properties and Corrosion Resistance. this Study Presents the Defects Observed during Optimization of the Processing Parameters for the Fabrication of Powder Injection Molding (PIM) of 316L SS Parts. in this Study, Five Formulations of Feedstock Containing 60-71vol% of Metal Powder Were Prepared Using a Wax-Based Binder. Green Samples Were Injection-Moulded, Followed by Binder Removal by Solvent and Thermal Means. Paraffin Wax (major Binder) Was Extracted at Various Temperatures in Order to Determine the Solvent Extraction Temperature. the Thermal De-Binding Was Performed Successfully at a Temperature of 450°C by Varying the Heating Rate from 1°C/min -10°C/min. SEM Results Showed Complete Removal of the Plastic Binder. Test Samples Were Sintered at Various Temperatures and Atmospheres. the Defects Observed during Solvent Extraction Were Swelling, Cracks and, at the Thermal De-Binding Step, Collection of Binder, Swelling and Holes. Sintered Samples Showed a Loss of Dimensional Control. these Types of Defect Were Considered to Be due to Inappropriate Heating Rates, Temperature and Dwell Time at each Process Step.

scholarly journals Separation of Aluminum and Iron from Lanthanum—A Comparative Study of Solvent Extraction and Hydrolysis-Precipitation

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 556
Author(s):  
Adam Balinski ◽  
Norman Kelly ◽  
Toni Helbig ◽  
Christina Meskers ◽  
Markus Andreas Reuter
Keyword(s):  
Solvent Extraction ◽  
Organic Phase ◽  
Ph Value ◽  
Naphthenic Acid ◽  
Complete Removal ◽  
Sulfate Solution ◽  
Aluminum Concentration ◽  
Precipitation Method ◽  
Strong Increase ◽  
Ph Range

This study investigates the removal of aluminum and iron from rare earth element (REE) containing solutions by solvent extraction with saponified naphthenic acid and by hydrolysis-precipitation. The results emphasize both, the preferential application as well as limitations of every method. We find that emulsification occurring during the solvent extraction of aluminum is caused by its slow extraction rate in comparison to the neutralization reaction and by the proximity of the pH value required for aluminum extraction and the pH value at which hydrolysis of aluminum occurs. However, by choosing a long shaking time of at least 4 h, the emulsion recedes. The formation of emulsion can be avoided by strict control of pH value during the extraction. Moreover, the loading capacity of the organic phase with aluminum is limited due to the strong increase in viscosity of the organic phase with increasing aluminum concentration and due to the gel formation. Regarding the extraction of iron, the amount of extracted ions is limited due to the overlap of the pH range required for the extraction with pH range in which sparingly soluble iron oxides/hydroxides are formed. In summary, aluminum and iron can be simultaneously removed from REE-sulfate solution by solvent extraction with saponified naphthenic acid in one extraction stage only from diluted solutions. However, in comparison to the hydrolysis-precipitation method, a higher purity of the solution is achieved. A complete removal of aluminum and iron from concentrated solutions can be achieved in two stages. First, the content of aluminum and iron should be reduced by hydrolysis-precipitation. After that, a high-purity solution can be obtained by subsequent solvent extraction by saponified naphthenic acid.

Complete removal of mycoplasma from viral preparations using solvent extraction

1995 ◽  
Vol 52 (1-2) ◽  
pp. 51-54 ◽  
Author(s):  
May La Linn ◽  
A.J.D. Bellett ◽  
P.G. Parsons ◽  
A. Suhrbier
Keyword(s):  
Solvent Extraction ◽  
Complete Removal

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

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