scholarly journals CALCITE POWDER DEFORMATION IN THE PRESENCE OF AQUEOUS SOLUTIONS OF VARIOUS COMPOSITION

Author(s):  
Ярослав Игоревич Симонов ◽  
Зоя Николаевна Скворцова ◽  
Владимир Юрьевич Траскин

Измеренные скорости уплотнения порошка кальцита под действием одноосной нагрузки в присутствии насыщенного раствора CaCO, содержащего катионы магния или гумат-анионы, сопоставлены с расчетами скорости деформации, проведенными с учетом растворимости, кинетики растворения и скорости массопереноса вещества матрицы в поровой жидкости. Адекватность предложенной схемы расчета подтверждается незначительным различием экспериментальных и вычисленных значений (в пределах 20 %). Показано, что скорость деформации кальцита в растворах, содержащих ионы магния, лимитируется скоростью растворения материала из-за доломитизации поверхности. Замедление скорости уплотнения в присутствии гумат-анионов также происходит из-за частичного блокирования поверхности в результате адсорбции гумата. The rates of calcite powder compaction under uniaxial stress in CaCO saturated aqueous solutions containing magnesium cations or humate anions have been compared with computed rate estimations. The interplay of calcite solubility, dissolution kinetics, and mass transfer rate of solid matter through the liquid bulk controls the overall process kinetics. A not significant difference between the experimental and calculated datasets (within 20%) confirms the adequacy of the model proposed. The calcite creep rate in magnesium-containing media is limited by the material dissolution stage as a result of the surface dolomitization. The creep hindering by humate anions is likely to be due to the partial surface coverage with adsorbed matter.

2003 ◽  
Vol 68 (11) ◽  
pp. 2080-2092 ◽  
Author(s):  
Martin Keppert ◽  
Josef Krýsa ◽  
Anthony A. Wragg

The limiting diffusion current technique was used for investigation of free convective mass transfer at down-pointing up-facing isosceles triangular surfaces of varying length and inclination. As the mass transfer process, copper deposition from acidified copper(II) sulfate solution was used. It was found that the mass transfer rate increases with inclination from the vertical to the horizontal position and decreases with length of inclined surface. Correlation equations for 7 angles from 0 to 90° were found. The exponent in the ShL-RaL correlation ranged from 0.247 for the vertical case, indicating laminar flow, to 0.32 for inclinations of 60 to 90°, indicating mixed or turbulent flow. The general correlation ShL = 0.358(RaL sin θ)0.30 for the RaL sin θ range from 7 × 106 to 2 × 1011 and inclination range from 15 to 90° was obtained.


2000 ◽  
Vol 55 (7) ◽  
pp. 1257-1267 ◽  
Author(s):  
Tiruta-Barna Ligia ◽  
Barna Radu ◽  
Moszkowicz Pierre ◽  
Bae Hae-Ryong

RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109978-109982 ◽  
Author(s):  
Young-Kee Kim ◽  
Sung-Yeob Lee ◽  
Byung-Keun Oh

In an enzyme process using a gas substrate, the enhanced gas liquid mass transfer rate of the gas substrate by methyl-functionalized mesoporous nanoparticles could improve the productivity.


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