REACTIONS BETWEEN SOLID CALCIUM CARBONATE AND ORTHOPHOSPHATE SOLUTIONS

1955 ◽  
Vol 33 (4) ◽  
pp. 665-671 ◽  
Author(s):  
J. S. Clark ◽  
R. C. Turner
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Dicalcium Phosphate ◽  
Partial Pressures ◽  
Stable Product ◽  
Normal Calcium ◽  
Carbonate Equilibrium

Studies of the reactions between solid calcium carbonate and orthophosphate solutions at low partial pressures of carbon dioxide indicated that hydroxyapatite was the stable product formed in these systems. Hydroxyapatite precipitated directly even though dicalcium phosphate formed initially under certain conditions. The reactions with orthophosphate did not seriously disturb the normal calcium carbonate equilibrium with the solution.

Equilibria of Reactions Between Nitrogen Oxides and Calcium Hydroxide

1995 ◽  
Vol 60 (5) ◽  
pp. 751-762
Author(s):  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Calcium Carbonate ◽  
Nitrogen Oxides ◽  
Calcium Hydroxide ◽  
Nitrogen Monoxide ◽  
Equilibrium Equations ◽  
Gaseous Nitrogen ◽  
Chemical Equilibria ◽  
Partial Pressures

A general analysis of chemical equilibria in a system consisting of the gaseous nitrogen monoxide, nitrogen dioxide, water vapor, carbon dioxide, oxygen, and the solid calcium hydroxide is carried out with respect to the equilibrium partial pressures of nitrogen oxides. The conditions are defined, under which the calcium hydroxide is transformed to the calcium carbonate. The corresponding equilibrium equations are derived for all nine regions of existence of described system. The results are illustrated graphically and discussed from the point of removing the nitrogen oxides from waste gases.

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.

Inspiratory Speech as a Management Option for Spastic Dysphonia

1992 ◽  
Vol 101 (5) ◽  
pp. 375-382 ◽  
Author(s):  
Gordon A. Harrison ◽  
Richard H. Troughear ◽  
Pamela J. Davis ◽  
Alison L. Winkworth
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Voice Quality ◽  
Management Option ◽  
Communication Problems ◽  
Partial Pressures ◽  
The Subject ◽  
And Control ◽  
Laryngeal Resistance

A case study is reported of a subject who has used inspiratory speech (IS) for 6 years as a means of overcoming the communication problems of long-standing adductor spastic dysphonia (ASD). The subject was studied to confirm his use of IS, determine the mechanisms of its production, investigate its effects on ventilatory gas exchange, and confirm that it was perceptually preferable to ASD expiratory speech (ES). Results showed that the production and control of a high laryngeal resistance to airflow were necessary for usable IS. Voice quality was quantitatively and perceptually poor; however, the improved fluency and absence of phonatory spasm made IS the preferred speaking mode for both the listener and the speaker. Transcutaneous measurements of the partial pressures of oxygen and carbon dioxide in the subject's blood were made during extended speaking periods. These measurements indicated that ventilation was unchanged during IS, and that ventilation during ES was similar to the “hyperventilation” state of normal speakers. The reasons for the absence of phonatory spasm during IS are discussed, and the possibility of its use as a noninvasive management option for other ASD sufferers is addressed.

scholarly journals A Novel Method for Calcium Carbonate Deposition in Wood That Increases Carbon Dioxide Concentration and Fire Resistance

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 72
Author(s):  
Vicente Hernandez ◽  
Romina Romero ◽  
Sebastián Arias ◽  
David Contreras
Keyword(s):  
Carbon Dioxide ◽  
Weight Gain ◽  
Calcium Carbonate ◽  
Fire Resistance ◽  
Carbon Dioxide Concentration ◽  
Wood Products ◽  
Vacuum Impregnation ◽  
Carbonate Deposition ◽  
Novel Method ◽  
Calcium Carbonate Deposition

In this study, a novel method for calcium carbonate deposition in wood that increases carbon dioxide concentration and fire resistance is proposed. The method promoted the mineralization of radiata pine wood microstructure with calcium carbonate by using a process consisting in the vacuum impregnation of wood with a calcium chloride aqueous solution and the subsequent sequential diffusion of gaseous ammonium and carbon dioxide. In the most favorable conditions, the method yielded a weight gain of about 20 wt.% due to mineralization, which implied the accumulation of 0.467 mmol·g−1 of carbon dioxide in the microstructure of wood. In addition, a weight gain of about 8% was sufficient to provide fire resistance to a level similar to that achieved by a commercially available fire-retardant treatment. The feasibility of retaining carbon dioxide directly inside the wood microstructure can be advantageous for developing wood products with enhanced environmental characteristics. This method can be a potential alternative for users seeking materials that could be effective at supporting a full sustainable development.

scholarly journals Decarbonisation of calcium carbonate at atmospheric temperatures and pressures, with simultaneous CO2 capture, through production of sodium carbonate

2021 ◽  
Author(s):  
Theodore Hanein ◽  
Marco Simoni ◽  
Chun Long Woo ◽  
John L Provis ◽  
Hajime Kinoshita
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Co2 Emissions ◽  
High Temperatures ◽  
Sodium Carbonate ◽  
Co2 Capture ◽  
Major Contributor ◽  
Calcination Process ◽  
Carbon Dioxide Co2

The calcination of calcium carbonate (CaCO3) is a major contributor to carbon dioxide (CO2) emissions that are changing our climate. Moreover, the calcination process requires high temperatures (~900°C). A novel...

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