ChemInform Abstract: EXISTENCE OF A NEW PHASE IN THE BARIUM CARBONATE-BARIUM SULFATE SYSTEM

1982 ◽  
Vol 13 (17) ◽  
Author(s):  
B. HAJEK ◽  
J. ONDRACEK ◽  
A. MUCK
2021 ◽  
Vol 2131 (3) ◽  
pp. 032065
Author(s):  
O Girikov ◽  
E Matyushenko ◽  
E Voitov

Abstract The research on the removal of sulfates from mine wastewater is presented in the article. A new purification method has been proposed that allows removing a significant part of sulfates by precipitation in the form of barium sulfate. The present studies were devoted to the removal of sulfates from mine wastewater with a sulfate content of 1050 mg/l by introducing various doses of barium-containing reagents, namely barium chloride, hydroxide and barium carbonate. Among the listed reagents, the best results were obtained, using barium chloride and hydroxide. The use of barium chloride with a dose of 2700 mg/l and barium hydroxide with a dose of 3200 mg/l made it possible to reduce the concentration of sulfates below the maximum permissible (100 mg/l) when discharged into a reservoir for fishery purposes. A reliable in operation technological scheme for removing sulfates from highly concentrated mine wastewater has been developed, which makes it possible to reduce sulfates in the treated waste liquid discharged into the reservoir to 100 mg/l and below. In this case, the purification is carried out with separation of streams - in a smaller part (about 26% of the incoming); barium chloride is introduced, in the second - barium hydroxide. After that, the streams are mixed again, settled, sent to the calciner and to the post-treatment facilities and discharged into the reservoir. The resulting sludge is stored in special landfills or is processed to extract valuable components.


Author(s):  
K. Takiyama

The coprecipitation of two sparingly soluble compounds in the aqueous solution has been studied by means of electron microscopy and x-ray diffraction techniques, and the properties of the particles produced by the coprecipitation were discussed as an issue in crystal chemistry. In the present investigation the coprecipitation of barium sulfate and barium carbonate was studied. Both crystals belong to the orthorhombic system. The lattice constants of barium sulfate are ao=8.878, bo=5.450 and co=7.152 Å. Those of barium carbonate are ao=5.314, bo=8.902 and co=6.430 Å. The ratio of the lattice constants of barium sulfate is different from that of barium carbonate. In this investigation, the relation of the morphological properties of the particles with the crystallographic properties of the component compounds was discussed. As the particles became very small when the precipitation was carried out at room temperature, in the present investigation the coprecipitation was done at 80°C to produce larger particles to study the morphological properties of the particles.


1960 ◽  
Vol 04 (03) ◽  
pp. 342-348 ◽  
Author(s):  
William J. Baker ◽  
Walter H. Seegers

SummaryPlatelet cofactor I preparations from bovine plasma were studied from the viewpoint of stability in the presence of chemicals selected strategically. The preparations were of high quality having about 86 per cent of the protein as one component by ultracentrifuge analysis. The activity was easily destroyed with hydrogen peroxide, sodium sulfite, phenylhydrazine, formalin, acetone, and by the process of freeze drying. The activity was not lost in the presence of oxygen, ascorbic acid, cysteine, merthiolate, parachloromercuribenzoate or 0.5 per cent phenol. In the native plasma the activity is not adsorbed on barium carbonate, barium sulfate, or magnesium hydroxide. Nor is it destroyed by ether; but, in purified form it is adsorbed on these adsorbants and is destroyed by ether. In the purified preparations the activity was not adsorbed on IRC-50 resin thus making it possible to use this adsorbant to remove any thrombin that might be added to a platelet cofactor I preparation. By this technic it was possible to show that thrombin alone does not easily destroy platelet cofactor I activity.


1982 ◽  
Vol 47 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Bohumil Hájek ◽  
Jan Ondráček ◽  
Alexander Muck

The infrared spectroscopy, X-ray diffraction, TGA and DTA, and microscopic analysis techniques were applied to a study of BaCO3-BaSO4 systems, performed on samples prepared by precipitation from dilute aqueous solutions. A new BaCO3. 3 BaSO4 phase was established in the system with the BaSO4 structure exhibiting parallel extinction (replacement of the SO42- anion by a CO32- anion, the d values are equal). The BaCO3-BaCO3. 3 BaSO4 region contains a mixture of the two phases, the latter phase, however, may be oversaturated by carbonate. In the BaCO3. 3 BaSO4-BaSO4 region, unstable phases are formed with a lower content of carbonate.


Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Patrycja Kowalik ◽  
Dorota Kopyto ◽  
Mateusz Ciszewski ◽  
Michał Drzazga ◽  
Katarzyna Leszczyńska-Sejda

This work focused on purifying copper electrolytes from a bismuth impurity on a laboratory scale. The electrolyte came from Polish copper electrorefineries with the content of main components, g/dm3: 49.6 Cu, 160 H2SO4. The electrolyte was enriched in bismuth by Bi2O3 addition. Purification of bismuth contamination was carried out using selected agents with adsorbing effects, such as barium hydroxide octahydrate, strontium carbonate, barium carbonate, barium and lead sulfates. The trials were performed until achieving the Bi level—below 0.1 g/dm3. During the experiments, it was noticed that electrolyte purification degree depends on initial Bi concentration in electrolyte, time and temperature, as well as on the type and amount of the bismuth-lowering agent. The most satisfactory results of Bi impurity removal were with additions of barium hydroxide octahydrate, strontium carbonate and barium carbonate to electrolyte at 60 °C for 1 h. These parameters revealed the highest electrolyte purification degree. Bismuth is not removed effectively from electrolytes by barium sulfate or lead sulfate addition. The efficiency of the purification process is much higher when the agents are added to the solution in the form of carbonates or hydroxides. Extending the electrolyte purification process time may cause dissolution of bismuth from the resulting precipitate and increase of bismuth concentration in electrolytes.


1967 ◽  
Vol 17 (01/02) ◽  
pp. 247-255 ◽  
Author(s):  
D. M Kerwin ◽  
J. H Milstone

SummaryCommercial thrombin was shown to contain appreciable amounts of thrombokinase. Passage through a DEAE-cellulose column substantially reduced the thrombokinase titer, although significant contamination could still be detected. Similarly, repeated barium sulfate adsorptions failed to remove the thrombokinase completely.However, barium sulfate adsorptions followed by passage through a column of DEAE-cellulose resulted in an essentially complete removal of the contaminant. Thrombin, so obtained, did not accelerate activation of prothrombin in the presence of calcium, phosphatide and barium carbonate adsorbed serum.Thrombokinase, separated by chromatography, was able to activate prothrombin very slowly in the presence of oxalate. Comparably dilute thrombin fractions and the unfractionated commercial preparation either did not possess this capability, or else this capability was obscured by a concomitant loss of thrombin.


Author(s):  
T. Schober

Nb, Ta and V are prototype substances for the study of the endothermic reactions of H with metals. Such metal-hydrogen reactions have gained increased importance due to the application of metal-hydrides in hydrogen- und heat storage devices. Electron microscopy and diffraction were demonstrated to be excellent methods in the study of hydride morphologies and structures (1). - Figures 1 and 2 show the NbH and TaH phase diagrams (2,3,4). EM techniques have contributed substantially to the elucidation of the structures and domain configurations of phases β, ζ and ε (1,4). Precision length measurement techniques of distances in reciprocal space (5) recently led to a detailed understanding of the distortions of the unit cells of phases ζ and ε (4). In the same work (4) the existence of the new phase η was shown. It is stable near -68 °C. The sequence of transitions is thus below 70 %.


1961 ◽  
Vol 06 (03) ◽  
pp. 435-444 ◽  
Author(s):  
Ricardo H. Landaburu ◽  
Walter H. Seegers

SummaryAn attempt was made to obtain Ac-globulin from bovine plasma. The concentrates contain mostly protein, and phosphorus is also present. The stability characteristics vary from one preparation to another, but in general there was no loss before 1 month in a deep freeze or before 1 week in an icebox, or before 5 hours at room temperature. Reducing agents destroy the activity rapidly. S-acetylmercaptosuccinic anhydride is an effective stabilizing agent. Greatest stability was at pH 6.0.In the purification bovine plasma is adsorbed with barium carbonate and diluted 6-fold with water. Protein is removed at pH 6.0 and the Ac-globulin is precipitated at pH 5.0. Rivanol and alcohol fractionation is followed by chromatography on Amberlite IRC-50 or DEAE-cellulose. The final product is obtained by isoelectric precipitation.


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