scholarly journals LEACHING OF URANIUM ORES IN THE PROCESS OF SODIUM SULPHATE ELECTROLYSIS

2019 ◽  
pp. 113-117
Author(s):  
V.G. Nefedov ◽  
Yu.E. Sknar ◽  
O.A. Kharytonova
Keyword(s):  
Silicon Content ◽  
Acid Leaching ◽  
Sodium Sulphate ◽  
Chemical Concentration ◽  
Corrosion Activity ◽  
Electrode Layer ◽  
Tetravalent Uranium ◽  
Hexavalent Uranium ◽  
High Consumption ◽  
Ph Range

When uranium is extracted from concentrates with high silicon content, acid leaching is usually used. The disadvantage of this method is the high consumption, high cost and corrosion activity of the reagents. Moreover, for the oxidation of tetravalent uranium to highly soluble hexavalent uranium, it is necessary to process it with oxidizing agents, for example, oxygen. The work shows the possibility of development and chemical concentration of uranium ores using electrolysis of sodium sulfate. During electrolysis the pH in the anode chambers ranges from 2.2…2.5 to 0.5…0.7 in the near-electrode layer of the electrolyte, which corresponds to the pH range during leaching in agitators. Oxygen released at the anode is able to oxidize uranium to hexavalent one.

PRODUCTION AND CHARACTERIZATION OF ALUMINA NANOPARTICLES FROM GIRO CLAY VIA ACID LEACHING WITH SOL GEL METHOD

2021 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
S. O. Balogun ◽  
S. A. Yaro ◽  
M. Abdulwahab ◽  
A. Kasim
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Acid Leaching ◽  
Alumina Nanoparticles ◽  
High Alumina ◽  
Spectroscopic Techniques ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sol Gel Process ◽  
Ph Range

Alumina nanoparticles were synthesized from locally available high alumina clay, obtained from Giro in Kabbi State, through acid leaching with sol-gel method. The clay was leached with hydrofluoric acid and the aluminous solution produced was used as precursor to synthesis nanoparticles through sol gel process. The composition and structure of the clay and the particles produced were characterized using Fourier Transform Infrared (FTIR), X-ray diffraction and fluorescence Spectroscopic techniques, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). From the analyses, the clay sample was observed to be high in alumina and predominantly Kaolinitic in nature. During the sol-gel process, effective flocculation was obtained at slightly alkaline pH range (7.6 to 8.0) and a relative moderate temperature of 80oC. The result also shows that the aging time of the gel affected the size of the particles produced during the process, and the particles are mainly nano-alumina.

Taste responses of calves to various concentrations of different salts

1977 ◽  
Vol 25 (1) ◽  
pp. 11-17 ◽  
Author(s):  
M. J. Mehren ◽  
D. C. Church
Keyword(s):  
Sodium Phosphate ◽  
Molybdenum Trioxide ◽  
Sodium Sulphate ◽  
Cupric Chloride ◽  
Trace Minerals ◽  
Chemical Concentration ◽  
Monobasic Sodium Phosphate ◽  
Taste Response ◽  
Rejection Threshold ◽  
Preference Threshold

SUMMARYExperiments were conducted to observe the taste responses of male and female calves to various levels of sodium salts, chloride solutions, and trace minerals. Animals were penned individually and given a completely pelleted ration ad libitum. Trace mineralized salt was freely available.Using water as a basis for determination, a non-discrimination zone was established. This zone represented an intake ranging from 63 to 37%. Preference threshold was set at 80% of intake, while the rejection threshold was set at 20% of intake. Responses were determined by expressing the intake of the test solution as a percentage of the total intake during the test period. Responses at a given chemical concentration were measured during two 8-hr periods.Taste response observations were made on the following: 0·02, 0·08, 0·32 or 1·25% sodium chloride (NaCl), sodium sulphate (Na2SO4), sodium bicarbonate (NaHCO3), sodium carbonate, monobasic sodium phosphate (NaH2PO4), dibasic sodium phosphate (Na2HPO4), ammonium chloride, potassium chloride, calcium chloride, magnesium chloride, and manganese chloride. In addition, observations were made when 0·02, 0·08, 0·32 or 1·25% NaHCO3, Na2SO4, or Na2HPO4 were offered in opposition to equal concentrations of NaCl. The responses to 5, 10, 20, 40 and 60 p.p.m. concentrations of cupric chloride, zinc chloride, molybdenum trioxide and cobaltous chloride were observed also.

Separation of Pure Silicon from Al-Si Alloy Melts

2014 ◽  
Vol 783-786 ◽  
pp. 186-191 ◽  
Author(s):  
Ki Young Kim ◽  
Jong Sik Shin ◽  
Dong Wha Park
Keyword(s):  
Silicon Content ◽  
Acid Leaching ◽  
Primary Silicon ◽  
Density Difference ◽  
Centrifugal Separator ◽  
Solvent Refining ◽  
Pure Silicon ◽  
Centrifugal Method ◽  
Silicon Crystals ◽  
Two Phases

Pure silicon can be obtained from Al-Si alloys by a combination of solvent refining and centrifugation. Primary silicon crystals are separated in the form of a foam after centrifugation. A vertical centrifugal separator is used which needs no more effort for further separation since each part of the high and low silicon content is divided automatically into two pieces after centrifugation. This centrifugal method does not use the density difference between two phases as in other methods, but uses the order of solidification in Al-Si alloys. How to make the Si foam, its characteristics including its density and strength, and purity of the extracted Si particles after acid leaching are reviewed.

Efficiency in the Extraction of Pure Silicon from Al-Si Alloy Melts by a Combined Process of Solvent Refining and Centrifugation for Solar Silicon Feedstock

2013 ◽  
Vol 652-654 ◽  
pp. 1153-1156 ◽  
Author(s):  
Ki Young Kim ◽  
Ju Young Cho ◽  
Kum Hee Seo
Keyword(s):  
Apparent Density ◽  
Silicon Content ◽  
Weight Ratio ◽  
Acid Leaching ◽  
Combined Process ◽  
Rich Phase ◽  
Solvent Refining ◽  
Pure Silicon ◽  
Before And After ◽  
Solar Silicon

Solvent refining of silicon from Al-Si melts assisted by a centrifugation was investigated for three alloys in the Al-Si system. Silicon was successfully separated from aluminum-rich phase in the form of a foam by centrifugation. As the silicon content increased, the recovery decreased because less aluminum-rich phases remained in the silicon foam. The weight ratio before and after acid leaching of the silicon foam was inversely related to its apparent density before acid leaching. The purity of the extracted silicon decreased slightly with increased silicon content. The purity of the silicon flakes obtained from the Al - 30% Si alloy was 4N, except aluminum. Boron and phosphorus in the silicon flakes could be lowered effectively by decreasing the silicon content in the Al-Si alloys

Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Isolation And Characterization ◽  
Ph Range ◽  
Inhibition Studies ◽  
Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

VASCULAR CONNECTIVE TISSUE UNDER THE INFLUENCE OF THYROXINE

1961 ◽  
Vol 36 (2) ◽  
pp. 197-211 ◽  
Author(s):  
lb Lorenzen
Keyword(s):  
Connective Tissue ◽  
Vessel Wall ◽  
Aortic Wall ◽  
Calcium Content ◽  
Sodium Sulphate ◽  
Collagen Content ◽  
Histological Changes ◽  
Hexosamine Content ◽  
Healing Processes

ABSTRACT Biochemical and histological changes in the aortic wall of rabbits were demonstrated following injection of epinephrine and l-thyroxine during 2 weeks. The widespread gross and microscopic changes were accompanied by an increase in hexosamine content and uptake of 35S labeled sodium sulphate, and an increased calcium content, whereas the collagen content, assessed by determination of hydroxyproline, was reduced. Comparison with the effect of epinephrine injections alone showed that thyroxine intensified the damaging effect of epinephrine on the vessel wall and induced more pronounced mucopolysaccharide changes in the aortic wall, presumably acting as a link in the healing processes.

HETEROGENEITY OF LONG ACTING THYROID STIMULATING (LATS) – ACTIVITY, THYROGLOBULIN ANTIBODIES AND THYROID MICROSOMAL ANTIBODIES

1973 ◽  
Vol 73 (3) ◽  
pp. 483-488 ◽  
Author(s):  
F. Adlkofer ◽  
H. Schleusener ◽  
L. Uher ◽  
A. Ananos ◽  
C. Brammeier
Keyword(s):  
Isoelectric Focusing ◽  
Graves Disease ◽  
Thyroid Antibodies ◽  
Thyroglobulin Antibodies ◽  
Ph Range ◽  
Long Acting ◽  
Thyroid Microsomal Antibodies

ABSTRACT Crude IgG of sera from 3 patients with Graves' disease, which contained LATS-activity and/or thyroid antibodies, was fractionated by isoelectric focusing in a pH-range between 6.0 to 10.0. LATS-activity was found in IgG-subfractions from pH 7.5 to 9.5, thyroglobulin antibodies and thyroid microsomal antibodies from pH 6.0 to 10.0. It was not possible to separate LATS-activity from the thyroid antibodies by this technique. The results indicate that LATS and the thyroid antibodies are heterogeneous and of polyclonal origin.

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