Behavior of traces of refractory minerals in the lithium metaborate fusion-acid dissolution procedure

1983 ◽  
Vol 55 (14) ◽  
pp. 2451-2453 ◽  
Author(s):  
Cyrus. Feldman
Keyword(s):  
Acid Dissolution ◽  
Lithium Metaborate ◽  
Refractory Minerals

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

ACID DISSOLUTION STUDIES USING BRAZILIAN SERPENTINITE ROCKS APPLIED MINERAL CARBONATION

2016 ◽  
Author(s):  
Kely Vieira ◽  
Kely Vieira ◽  
Gretta Larisa Aurora Arce Ferrufino ◽  
Ivonete Ávila ◽  
Carlos Manuel Romero Luna ◽  
...  
Keyword(s):  
Mineral Carbonation ◽  
Acid Dissolution ◽  
Dissolution Studies

ICP-MS AND ICP-AES ANALYSIS OF PLANT REFERENCE MATERIALS

2019 ◽  
Vol 85 (6) ◽  
pp. 11-24
Author(s):  
I. V. Nikolaeva ◽  
A. A. Kravchenko ◽  
S. V. Palessky ◽  
S. V. Nechepurenko ◽  
D. V. Semenova
Keyword(s):  
Reference Material ◽  
Mass Spectrometer ◽  
Reference Materials ◽  
Atomic Emission ◽  
Icp Ms ◽  
Lithium Metaborate ◽  
Relative Standard ◽  
Microwave System ◽  
Total Analysis ◽  
Siberian Pine

Two methods — ICP-MS and ICP-AES are used for certification of the new reference material — needles of Siberian pine (NSP-1). Techniques of the analysis include decomposition of plant samples in two different ways: acid digestion in a microwave system MARS-5 and lithium metaborate fusion followed by ICP-MS and ICP-AES analysis of the solutions. Simultaneous determinations of all the elements were carried out in low, medium and high resolution using SF-mass-spectrometer ELEMENT and atomic-emission spectrometer IRIS Advantage with external calibrations and internal standards (In — ICP-MS, Sc —ICP-AES). Middle and high resolutions of ICP mass spectrometer were used for interference corrections. Data obtained by ICP-MS and ICP-AES with different decomposition techniques are in good agreement. The ICP-MS and ICP-AES techniques have been validated by the analysis of three plant reference materials: LB-1 (leaf of a birch), Tr-1 (grass mixture) and EK-1 (Canadian pondweed). These techniques were used for the determination of 38 elements in the new reference material NSP-1. Relative standard deviations for most of the determined elements were below 10%. Combination of ICP-MS and ICP-AES techniques for certification of the new reference material makes it possible to expand the set of elements to be determined and to reduce the total analysis time.

Mass transfer into the liquid in turbulent flow at high Schmidt numbers. Dissolution of benzoic acid into aqueous solutions of glycerol from internal surface of the pipe

1981 ◽  
Vol 46 (7) ◽  
pp. 1566-1576
Author(s):  
František Vašák ◽  
Václav Kolář ◽  
Zdeněk Brož
Keyword(s):  
Mass Transfer ◽  
Benzoic Acid ◽  
Aqueous Solutions ◽  
Cross Section ◽  
Circular Cross Section ◽  
Internal Surface ◽  
Theoretical Relation ◽  
Acid Dissolution ◽  
Schmidt Numbers ◽  
Unified Description

Theoretical relation derived in the last study for calculation of the mass transfer coefficient in the region of not fully developed concentration profile at high Schmidt numbers has been verified experimentally. This experimental study has been devoted to measurements of the rate of benzoic acid dissolution into aqueous solutions of glycerol from the internal surface of the pipe of circular cross section in the range 933 ⪬ Sc ⪬ 225 000 and 5 000 ⪬ Re ⪬ 50 000. It has been possible to explain on basis of the theoretical model, the differences between the data of various authors and to obtain a unified description of the phenomena.

Vibrational investigation of lithium metaborate-metaaluminate glasses and crystals

1997 ◽  
Vol 217 (2-3) ◽  
pp. 278-290 ◽  
Author(s):  
G.D. Chryssikos ◽  
M.S. Bitsis ◽  
J.A. Kapoutsis ◽  
E.I. Kamitsos
Keyword(s):  
Lithium Metaborate
Sign in / Sign up

Export Citation Format

Share Document