scholarly journals Limestone Clays for Ceramic Industry

2021 ◽  
Author(s):  
Herbet Alves de Oliveira ◽  
Cochiran Pereira dos Santos
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Oxide ◽  
Ceramic Industry ◽  
Magnesium Carbonate ◽  
Ceramic Tiles ◽  
High Loss ◽  
Loss Of Mass ◽  
Carbon Dioxide Co2 ◽  
Very High

Limestone clays are used in the ceramic segment in the manufacture of bricks, ceramic tiles, and in the production of cement, among others. Limestone can be present in soils in pure form or as a contaminant, but always from marine environments. The limestone after burning can present a high loss of mass (35–45%), which can cause serious problems with the sintering of ceramic products such as bricks, tiles. The calcium or magnesium carbonate once dissociated forms calcium oxide (CaO) and releases carbon dioxide (CO2). CaO in contact with water subsequently experiences very high expansions that can cause cracks in the materials. Researchers have studied procedures to inhibit limestone action on clays as well as to set the correct temperature for firing. In this chapter, examples of clays with different percentages of calcium carbonate (CaCO3) that are used in the ceramic segment and their characteristics will be given.

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...

Preparation of Plate-Shaped Calcium Carbonate and its Application in the Coating Paper

2011 ◽  
Vol 236-238 ◽  
pp. 1124-1127
Author(s):  
Sen Wang ◽  
Xin Ping Li ◽  
Er Lin Mao ◽  
Zhuo Yuan Cheng
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Oxide ◽  
High Performance ◽  
Air Permeability ◽  
Paper Coating ◽  
Reaction Conditions ◽  
Printing Ink

This paper deals with the preparation of Plate-shaped Calcium Carbonate and Its Application in the Paper Coating. calcium oxide and carbon dioxide were used as major materials to preparetion the Plate-shaped Calcium Carbonate, The best reaction conditions as follows: w(CaO)：w（H2O）=1：5, V（CO2）：V（atmosphere）=1：2. Then use the Plate-shaped Calcium Carbonate in spreading. The results show that the Plate-shaped Calcium Carbonate is a high-performance product that can obviously enhance the paper’s smoothness, whiteness, air permeability, printing ink absorbance.

Design of a Solar Thermochemical Reactor for Calcium Oxide Based Carbon Dioxide Capture

2015 ◽  
Author(s):  
Leanne Reich ◽  
Luke Melmoth ◽  
Robert Gresham ◽  
Terrence Simon ◽  
Wojciech Lipiński
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Oxide ◽  
Thermal Analyses ◽  
Reactor Design ◽  
Gas Flows ◽  
Carbonate Carbon ◽  
Calcination Step ◽  
Oxide Particles ◽  
Concentrated Solar Radiation

An engineering design for a 1-kW dual-cavity solar-driven reactor to capture carbon dioxide via the calcium oxide based two-step carbonation-calcination cycle is presented. In the low temperature carbonation step, gas containing up to 15% carbon dioxide flows through a gas manifold and plenum into an annular reaction zone filled with calcium oxide particles. The carbon dioxide reacts with the calcium oxide, forming calcium carbonate. Carbon dioxide-depleted gas flows out of the reactor through a second gas manifold. In the high temperature calcination step, concentrated solar radiation enters the beam-up oriented, windowless reactor and is absorbed by the diathermal cavity wall, which transfers heat via conduction to the calcium carbonate particles formed in the previous step. The calcium carbonate dissociates into calcium oxide and carbon dioxide. Additional carbon dioxide is used as a sweep gas to ensure high purity carbon dioxide at the outlet. Mechanical and thermal analyses are conducted to refine an initial reactor design and identify potential design shortcomings. Numerically predicted temperature profiles in the reactor are presented and the final reactor design is established.

scholarly journals Decarbonising the Portland and other Cements—Via Simultaneous Feedstock Recycling and Carbon Conversions Sans External Catalysts

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2462
Author(s):  
Sheila Devasahayam
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Carbon Footprint ◽  
Elevated Temperatures ◽  
Clean Energy ◽  
Magnesium Carbonate ◽  
Methane Emissions ◽  
Carbon Conversion ◽  
Waste Plastics

The current overarching global environmental crisis relates to high carbon footprint in cement production, waste plastic accumulation, and growing future energy demands. A simultaneous solution to the above crises was examined in this work. The present study focused on decarbonizing the calcination process of the cement making using waste plastics and biowastes as the reactants or the feedstock, to reduce the carbon footprint and to simultaneously convert it into clean energy, which were never reported before. Other studies reported the use of waste plastics and biowastes as fuel in cement kilns, applicable to the entire cement making process. Calcination of calcium carbonate and magnesium carbonate is the most emission intensive process in cement making in Portland cements and Novacem-like cements. In the Novacem process, which is based on magnesium oxide and magnesium carbonates systems, the carbon dioxide generated is recycled to carbonate magnesium silicates at elevated temperatures and pressures. The present study examined the Novacem-like cement system but in the presence of waste plastics and biomass during the calcination. The carbon dioxide and the methane produced during calcination were converted into syngas or hydrogen in Novacem-like cements. It was established that carbon dioxide and methane emissions were reduced by approximately 99% when plastics and biowastes were added as additives or feedstock during the calcination, which were converted into syngas and/or hydrogen. The reaction intermediates of calcination reactions (calcium carbonate–calcium oxide or magnesium carbonate–magnesium oxide systems) can facilitate the endothermic carbon conversion reactions to syngas or hydrogen acting as non-soot forming catalysts. The conventional catalysts used in carbon conversion reactions are expensive and susceptible to carbon fouling. Two criteria were established in this study: first, to reduce the carbon dioxide/methane emissions during calcination; second, to simultaneously convert the carbon dioxide and methane to hydrogen. Reduction and conversion of carbon dioxide and methane emissions were facilitated by co-gasification of plastics and bio-wastes.

scholarly journals Discussion after Paper by Mustel

1974 ◽  
Vol 66 ◽  
pp. 196-197
Keyword(s):  
Mass Loss ◽  
Large Mass ◽  
Heavy Elements ◽  
High Loss ◽  
Loss Of Mass ◽  
Very High

Tayler: I wish to provoke some discussion between observers and theoreticians. Theoreticians require supernovae to produce large amounts of heavy elements and that very large mass loss should occur. However, it is not clear that observers ever see a very high loss of mass or very large amounts of heavy elements. Is this a serious discrepancy?

The dissociation of dolomite

1923 ◽  
Vol 20 (101) ◽  
pp. 54-59 ◽  
Author(s):  
Cecil S. Garnett
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Magnesium Oxide ◽  
Magnesium Carbonate ◽  
Considerable Reduction ◽  
Refractory Minerals

That dolomite (CaCO3 . MgCO3) on being heated behaves as though it were a mixture of the two carbonates by dissociating in two distinct stages, appears to be the widely accepted opinion. Thus it is staled (Mem. Geol. Survey, Special Reports on Min. Resources, London, 1920, vol. 16, ‘Refractory Minerals’, p. 102) ‘On calcination, dolomite undergoes a progressive dissociation which may be considered chemically as covering two distinct stages. The first effect of rising temperature is the expulsion of carbon dioxide from the magnesium carbonate contained in the dolomite and the formation of a mixture of magnesium oxide and calcium carbonate, accompanied by a considerable reduction in volume… . Complete calcination results in the expulsion of the remaining carbon dioxide, a still further reduction in volume, and the production of a dense crystalline aggregate of magnesium and calcium oxides.’

scholarly journals Synergism Between Phosphine (PH3) and Carbon Dioxide (CO2): Implications for Managing PH3 Resistance in Rusty Grain Beetle (Laemophloeidae: Coleoptera)

2020 ◽  
Vol 113 (4) ◽  
pp. 1999-2006
Author(s):  
Myrna Constantin ◽  
Rajeswaran Jagadeesan ◽  
Kerri Chandra ◽  
Paul Ebert ◽  
Manoj K Nayak
Keyword(s):  
Carbon Dioxide ◽  
Reference Strain ◽  
Fold Increase ◽  
Stored Grain ◽  
Response Data ◽  
Alternative Approach ◽  
Mortality Response ◽  
High Concentrations ◽  
Carbon Dioxide Co2 ◽  
Very High

Abstract Strong resistance to phosphine (PH3) in the rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Laemophloeidae: Coleoptera) poses a serious risk to stored-grain biosecurity. Resistant populations hold risk of surviving in PH3 fumigation, particularly in storage structure that limits achieving very high concentrations of PH3, demanding the need for alternative fumigation strategies. Cofumigation with PH3 and carbon dioxide (CO2) is one alternative approach that has the potential to be used widely. CO2 fumigation of adults of strongly PH3-resistant reference strain of C. ferrugineus, for 48 h, showed that the effective concentration (LC50) of CO2 was 30.99%. This 30% level of CO2 in combination with PH3 decreased the LC50 of PH3 from 6.7 mg/liter to 0.84 mg/liter, an eightfold increase in PH3 efficacy relative to PH3 fumigation in normal air. The LC99.9 decreased from 16.2 mg/liter to 5.8 mg/liter, a 2.8-fold increase in PH3 efficacy. Comparison of mortality response data of PH3 alone and the PH3 + CO2 mixture confirmed that CO2 enhances the toxicity of PH3 synergistically in addition to exerting its own toxicity. These results were validated against three independently field-derived strains of strongly resistant C. ferrugineus that confirmed that observed enhancement in toxicity with the PH3 + CO2 mixture was consistent, irrespective of differences in resistance phenotypes and inherent tolerance levels. Results of the current study provide further opportunities to develop new commercially viable strategy to control strongly PH3-resistant C. ferrugineus.

Tribological Studies of Compressor Surfaces in the Presence of Carbon Dioxide Under Extreme Environmental Pressure Conditions

2005 ◽  
Author(s):  
Nicholaos G. Demas ◽  
Andreas A. Polycarpou
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
High Pressures ◽  
Environmental Pressures ◽  
Thermodynamic Studies ◽  
Environmental Pressure ◽  
Ultra High Pressure ◽  
Carbon Dioxide Co2 ◽  
Internal Pressures ◽  
Very High

The refrigeration industry has shown an inclination towards the use of carbon dioxide (CO2) as a refrigerant in some applications. While extensive thermodynamic studies exist, tribological studies with CO2 are limited and tribological testing has further been restricted to low environmental pressures up to 1.38 MPa (200 psi) due to limitations in equipment capabilities. In this work, experiments were performed using an Ultra High Pressure Tribometer (UHPT) that was custom designed and built for tribological testing of compressor contact interfaces at very high environmental pressures up to 13.8 MPa (2000 psi). These tests demonstrate the possibility of testing at very high pressures similar to the internal pressures of CO2 compressors.

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