PEG-assisted controlled precipitation of calcium hydroxide and calcium carbonate nanostructures for cement reinforcement

2021 ◽  
pp. 124865
Author(s):  
Ilaha Hasanova ◽  
Ulviyya Hasanova ◽  
Eldar Gasimov ◽  
Fuad Rzayev ◽  
Elman Hajiyev ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Controlled Precipitation

Controlled preparation of micro–nano hierarchical hollow calcium carbonate microspheres by pressurized-CO2 carbonization and their CaCO3:Eu3+ photoluminescence properties

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3033-3042
Author(s):  
Liubin Shi ◽  
Mingde Tang ◽  
Yaseen Muhammad ◽  
Yong Tang ◽  
Lulu He ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Hierarchical Structure ◽  
Ethylenediaminetetraacetic Acid ◽  
Disodium Salt ◽  
Hollow Microspheres ◽  
Photoluminescence Properties ◽  
Controlled Preparation

Herein, calcium carbonate hollow microspheres with a micro–nano hierarchical structure were successfully synthesized using disodium salt of ethylenediaminetetraacetic acid (EDTA-2Na) as an additive, by bubbling pressurized carbon dioxide and calcium hydroxide at 120 °C.

PREPARATION OF PRECIPITATED CALCIUMCARBONATE USING ADDITIVE AND WITHOUT ADDITIVE

2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Anuar Othman ◽  
Nasharuddin Isa ◽  
Rohaya Othman
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Mineral Composition ◽  
Hydrated Lime ◽  
Raw Material ◽  
Precipitated Calcium Carbonate ◽  
Uniform Size ◽  
The One

Precipitated calcium carbonate (PCC) chemically can be synthesized in the laboratory. In this study, hydrated lime or calcium hydroxide was used as raw material with sucrose as additive to produce PCC. The process was compared with the one without additive. PCC produced was observed based on morphology, mineral composition and size by using Fesem-Edx and LPSA, respectively. PCC products without additive demonstrated fine and more uniform size of calcite PCC as compared to the one with additive. Nevertheless, the process with additive produced more PCC product than without additive.

scholarly journals Comparative Efficacy of Montmorillonite, Calcium Hydroxide, Calcium Carbonate in pH Restoration of Acidified Freshwater Bodies

2020 ◽  
Author(s):  
Om Kolhe ◽  
Aidan Moy
Keyword(s):  
Calcium Carbonate ◽  
Acid Rain ◽  
Calcium Hydroxide ◽  
Alternative Methods ◽  
Comparative Efficacy ◽  
Ph Change ◽  
Ecological Consequences ◽  
Freshwater Bodies ◽  
Freshwater Acidification

Freshwater acidification is the result of acid rain precipitating over a freshwater body. There are significant ecological consequences that result from such precipitation, as ecosystems surrounding freshwater bodies are destroyed because many of the organisms in these ecosystems cannot tolerate the pH change caused by acid rain. Current solutions involve a technique known as liming, where powdered calcium carbonate is added to freshwater bodies creating a buffer that helps neutralize the acidity caused by acid rain. However, scientists have been searching for alternative methods to combat the decrease in pH caused by freshwater acidification, by using substitute compounds. In this experiment, we test the efficacy of alternate solutions involving montmorillonite and calcium hydroxide when compared to the currently employed method of using calcium carbonate to combat acidification.

Precursors Influence on CaCu3Ti4O12 Synthesis

2012 ◽  
Vol 727-728 ◽  
pp. 1313-1316 ◽  
Author(s):  
Maria Virginia Gelfuso ◽  
Gabriel Moreira Lima ◽  
Daniel Thomazini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Room Temperature ◽  
Microstructural Analysis ◽  
Copper Nitrate ◽  
N Powder ◽  
Scanning Electron

In this work CCTO have been synthesized in two different chemical precursors: calcium hydroxide and copper sulfate were used to compose CCTO-S powder while calcium carbonate and copper nitrate were used to form CCTO-N powder. Calcinations conditions were dramatically different in terms of shelf time and temperature. The CCTO phase was fully obtained for 3 hours of calcination in CCTO-N against the 24 hours to form the same phase in CCTO-S powder. Ceramic bodies densities values for CCTO-S samples were 95% of theoretical density (5.05 g/cm3) and 98% for CCTO-N. The dielectric constant, at room temperature, was obtained for ceramics processed by two routes. Microstructural analysis was conducted by Scanning Electron Microscopy (SEM) and it was performed to explain the dielectric constant differences between CCTO-S and CCTO-N ceramics.

Synthesis of Calcium Carbonate-Polyethylene Oxide Hybrid Nanofibers Through In-Situ Electrospinning

2008 ◽  
Vol 8 (5) ◽  
pp. 2627-2631 ◽  
Author(s):  
Reza Faridi-Majidi ◽  
Naser Sharifi-Sanjani ◽  
Mohammad Madani
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Polyethylene Oxide ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Hybrid Nanofibers ◽  
Carbon Dioxide Atmosphere ◽  
Transmission Electron ◽  
Gaseous Carbon Dioxide

In this work, calcium carbonate nanoparticles-polyethylene oxide nanofibers as organic–inorganic hybrid were prepared via in-situ electrospinning. Thus, electrospinning of polyethylene oxide solution saturated with calcium hydroxide was carried out in gaseous carbon dioxide atmosphere. Transmission electron microscopy (TEM) showed that calcium carbonate (CaCO3) nanoparticles were formed on the produced nanofibers of 200–300 nm in diameter. The existence of the formed CaCO3 was also proved by thermogravimetric analysis (TGA) via loss of gaseous CO2 related to the decomposition of CaCO3 at about 500–840 °C. X-ray diffraction (XRD) analysis of the nanofibers showed that the formed CaCO3 nanoparticles have vaterite morphology. DSC analysis was used to determine melting point and to calculate the crystallinity of the produced hybrid nanofibers. The TEM, TGA, XRD and DSC analyses results of the obtained nanofibers were compared with those of the nanofibers produced in electrospinning of pure polyethylene oxide solution and polyethylene oxide solution having calcium hydroxide, both in air.

Study of Carbonizing Processes for Sintered Dolomite

2007 ◽  
Vol 336-338 ◽  
pp. 2552-2555 ◽  
Author(s):  
Jing Hua Xue ◽  
Min Fang Han ◽  
Qing Yun Wang
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Magnesium Hydroxide ◽  
Room Temperature ◽  
Xrd Analysis ◽  
Magnesium Carbonate ◽  
Crystal Phase ◽  
Carbonization Process

It is the easy and widely used way to make light calcium carbonate and magnesium carbonate from dolomite by carbonizing process. During this process, the dolomite is calcined at different temperature, from 700°C to 950°C to get the mixture including either calcium carbonate and magnesia or calcia and magnesia. Then the mixture is blended with water in different temperature from room temperature to 80°C. As a result, it is supposed to get calcium hydroxide and magnesium hydroxide, but XRD analysis reveals that it is not accord with the theory. Magnesium hydroxide can not be obtained during this reaction. After the carbonization process, the calcium carbonate and a kind of mixture which is composed with different crystal phase of Mg5(CO3)4(OH)2[H2O]4 have been produced, instead of magnesium carbonate. The magnesia is gotten when the mixture is calcined at 450~750°C.

Fabrication of Calcium Carbonate with Exquisite Morphologies and Colors through a New Controlled Precipitation Approach

2004 ◽  
Vol 33 (10) ◽  
pp. 1248-1249 ◽  
Author(s):  
Wei Shan ◽  
Bo Wang ◽  
Ya-Hong Zhang ◽  
Bi-Yun Wu ◽  
Yi Tang
Keyword(s):  
Calcium Carbonate ◽  
Controlled Precipitation

scholarly journals Effects of Calcium Carbonate and Calcium Hydroxide on Gelatinization and Retrogradation of Corn Starch.

2001 ◽  
Vol 48 (10) ◽  
pp. 751-758 ◽  
Author(s):  
Megumi OTSUKA ◽  
Hatsue MORITAKA ◽  
Hiroyasu FUKUBA ◽  
Syuichi KIMURA ◽  
Miki ISHIHARA
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Corn Starch
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