Статті в журналах: "Sodium carbonate"

1

Coppola, Luigi, Denny Coffetti, Elena Crotti, Raffaella Dell’Aversano, Gabriele Gazzaniga, and Tommaso Pastore. "Influence of Lithium Carbonate and Sodium Carbonate on Physical and Elastic Properties and on Carbonation Resistance of Calcium Sulphoaluminate-Based Mortars." Applied Sciences 10, no. 1 (December 25, 2019): 176. http://dx.doi.org/10.3390/app10010176.

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In this study, three different hardening accelerating admixtures (sodium carbonate, lithium carbonate and a blend of sodium and lithium carbonates) were employed to prepare calcium sulphoaluminate cement-based mortars. The workability, setting times, entrapped air, elasto-mechanical properties such as compressive strength and dynamic modulus of elasticity, free shrinkage, water absorption and carbonation rate were measured and mercury intrusion porosimetry were also performed. Experimental results show that a mixture of lithium carbonate and sodium carbonate acts as a hardening accelerating admixture, improving the early-age strength and promoting a remarkable pore structure refinement. Finally, sodium carbonate also reduces the water absorption, the carbonation rate and the shrinkage of mortars without affecting the setting times and the workability.

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2

Pouhet, Raphaëlle, and Martin Cyr. "Studies of Natural and Accelerated Carbonation in Metakaolin-Based Geopolymer." Advances in Science and Technology 92 (October 2014): 38–43. http://dx.doi.org/10.4028/www.scientific.net/ast.92.38.

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The carbonation of Portland-cement-based materials involves the reaction between atmospheric CO2 and calcium ions in the pore solution. The formation of calcium carbonate is responsible for a decrease in the pH of the pore solution from 12.5 to 9, thus leading to the depassivation of steel reinforcements and their possible corrosion, and can also lead to efflorescence (white crystals formed on the surface). In metakaolin-based geopolymer activated by sodium silicate, in which calcium is almost non-existent, the presence of CO2 will lead to the formation of sodium carbonates. Since geopolymer can be carbonated, the risk of corrosion or efflorescence needs to be assessed. A pH study of the geopolymer pore solution showed a very fast decrease compared to OPC, with almost total carbonation after only 14 days. In natural atmospheric CO2 conditions, it was found that the formation of sodium carbonate did not lead to a decrease of the pH to below a value around 9, thus limiting the risk of corrosion by depassivation of reinforcement, but the large amount of carbonate suggested a significant risk of efflorescence. A study of accelerated carbonation performed under an atmosphere of 50% CO2 highlighted the formation of sodium bicarbonate resulting in a lower pH of the pore solution and a much larger amount of product formed. Finally the study of efflorescence carried out by semi-immersion tests in natural or accelerated conditions confirmed the different nature of the crystals formed (sodium carbonate or bicarbonate) but showed no significant impact on the amount of carbonated products. This study thus demonstrates that the accelerated carbonation test had very limited usefulness, given the rapidity of the natural reaction. Furthermore, it was found that this test did not reproduce reality as it led to different reaction products.

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3

Marinos, Danai, Dimitrios Kotsanis, Alexandra Alexandri, Efthymios Balomenos, and Dimitrios Panias. "Carbonation of Sodium Aluminate/Sodium Carbonate Solutions for Precipitation of Alumina Hydrates—Avoiding Dawsonite Formation." Crystals 11, no. 7 (July 20, 2021): 836. http://dx.doi.org/10.3390/cryst11070836.

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Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such solutions result from leaching calcium aluminate slags with sodium carbonate solutions, in accordance with the Pedersen process, which is an alternative process for alumina production. The concentration of carbonate ions in the pregnant solution is revealed as a key factor in controlling the nature of the precipitating phase. Synthetic aluminate solutions of varying sodium carbonate concentrations, ranging from 20 to 160 g/L, were carbonated, and the resulting precipitating phases were characterized by X-ray diffraction analysis. Based on the results of the previous carbonation tests, a series of experiments were performed in which the duration of carbonation and the aging period of the precipitates varied. For this work, a synthetic aluminate solution containing 20 g/L free Na2CO3 was used. The precipitates were characterized with X-ray diffraction analysis and Fourier-transform infrared spectroscopy.

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4

Алиев, А. Р., И. Р. Ахмедов, М. Г. Какагасанов та З. А. Алиев. "Колебательные спектры ионно-молекулярных кристаллов карбонатов в предпереходной области вблизи структурных фазовых переходов". Журнал технической физики 127, № 9 (2019): 429. http://dx.doi.org/10.21883/os.2019.09.48196.104-19.

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Molecular relaxation processes in lithium carbonate (Li2CO3), sodium carbonate (Na2CO3) and potassium carbonate (K2CO3) were studied by Raman spectroscopy. It has been established that in crystalline carbonates Li2CO3, Na2CO3 and K2CO3, the structural phase transition of the first kind is stretched (diffuse phase transition). The existence of the pretransition region in the studied carbonates Li2CO3, Na2CO3 and K2CO3 was found.

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5

Dusek, Michal, Gervais Chapuis, Mathias Meyer, and Vaclav Petricek. "Sodium carbonate revisited." Acta Crystallographica Section B Structural Science 59, no. 3 (May 23, 2003): 337–52. http://dx.doi.org/10.1107/s0108768103009017.

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We present the structure of anhydrous sodium carbonate at room temperature (phase γ) and 110 K (phase δ) based on single-crystal X-ray diffraction data. The incommensurate phase γ was determined almost 30 years ago in the harmonic approximation using one modulation wave and first-order satellites. In our work we use satellites up to fifth order and additional harmonic waves to model the anharmonic features of the structure. The commensurate phase δ is presented for the first time. Using the superspace approach, both phases are compared in order to find common trends in the whole range of the sodium carbonate phases. We present arguments supporting the hypothesis that the driving force of the phase transitions may originate in the unsaturated bonding potential of one of the Na ions.

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6

Young, Jay A. "Sodium Carbonate (anhydrous)." Journal of Chemical Education 79, no. 11 (November 2002): 1315. http://dx.doi.org/10.1021/ed079p1315.

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7

Young, Jay A. "Sodium Hydrogen Carbonate." Journal of Chemical Education 80, no. 11 (November 2003): 1250. http://dx.doi.org/10.1021/ed080p1250.

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8

&NA;. "Calcium carbonate/sodium bicarbonate." Reactions Weekly &NA;, no. 1201 (May 2008): 12. http://dx.doi.org/10.2165/00128415-200812010-00032.

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9

&NA;. "Magnesium carbonate/sodium picosulfate." Reactions Weekly &NA;, no. 1111 (July 2006): 15–16. http://dx.doi.org/10.2165/00128415-200611110-00048.

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10

Wu, Bing, Alena Sobina, Sebastian Recknagel, René Meinhardt, Griselda Rivera-Sánchez, José Luis Ortiz-Aparicio, Matilda Rozikova, et al. "Assay of sodium carbonate." Metrologia 60, no. 1A (January 1, 2023): 08004. http://dx.doi.org/10.1088/0026-1394/60/1a/08004.

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Main text The CCQM-K173 Assay of Sodium Carbonate key comparison was jointly organized by the Inorganic Analysis (IAWG) and Electrochemical Analysis and Classical Chemical Methods (EAWG) working groups of CCQM to test the abilities of the national metrology institutes (NMIs) to measure the purity or amount content of solid bases. They are important challenges for reference material producers, providers of other measurement services, such as proficiency testing schemes. Evidence of successful participation in formal, relevant international comparisons are needed to support calibration and measurement capability claims (CMCs) made by NMIs and designated institutes (DIs). Nine NMIs participated in this key comparison CCQM-K173. National Institute of Metrology P. R. China (NIM) and Ural Research Institute for Metrology - Affiliated Branch of the D.I. Mendeleyev Institute for Metrology (VNIIM-UNIIM), Russian Federation, acted as the coordinating laboratories of the comparison. The measurement methods used by the participants for measuring the amount content of bases expressed as sodium carbonate were coulometry and titrimetry. In general, good overlap of results was observed, the suitability of coulometry and titrimetry for assay of high purity materials was demonstrated. The majority of results were split in two groups differing from each. This bias was however covered by the stated uncertainty estimates. Various effects have been evaluated that may cause it. However, the reason for the bias has not been identified clearly. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

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11

Bedekar, S. G. "Properties of sodium carbonate-sodium bicarbonate solutions." Journal of Applied Chemistry 5, no. 2 (May 4, 2007): 72–75. http://dx.doi.org/10.1002/jctb.5010050206.

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12

Shestak, I. V., A. D. Vorobiev, D. V. Cherednichenko, E. V. Vorobyova, E. V. Laevskaya, and M. A. Astakhova. "Inhibition of calcium and magnesium carbonate crystallization with sodium polyacrylate." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 55, no. 3 (September 13, 2019): 377–87. http://dx.doi.org/10.29235/1561-8331-2019-55-3-377-384.

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It is known that when water are used for technological purposes, in circulating water supply systems of enterprises as a coolant during continuous heating and cooling, the formation of insoluble precipitates, most often calcium carbonates, occurs on the walls of heat exchangers, which leads to a large number of problems, even production can be stopped for cleaning equipment. To prevent the formation of salts, it is necessary to use precipitation inhibitors. Sodium polyacrylate was investigated as a precipitation inhibitor. The composition, morphology and IR spectra of calcium carbonate precipitate obtained in the absence and in the presence of sodium polyacrylate were studied. It was established that the effect of sodium polyacrylate on the mechanism of crystallization of carbonate sediment depends on the pH of the initial solution. The results of IR spectroscopy, X-ray diffraction analysis and images obtained by electron microscopy indicate the participation of polymer molecules in the formation of the crystalline structure of the carbonate precipitate.

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13

Chiotti, Premo, and Richard Markuszewski. "Binary systems sodium sulfide-sodium hydroxide and sodium carbonate-sodium hydroxide." Journal of Chemical & Engineering Data 30, no. 2 (April 1985): 197–201. http://dx.doi.org/10.1021/je00040a020.

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14

Zyman, Zoltan, and Mykola Tkachenko. "Sodium-carbonate co-substituted hydroxyapatite ceramics." Processing and Application of Ceramics 7, no. 4 (2013): 153–57. http://dx.doi.org/10.2298/pac1304153z.

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Powders of sodium-carbonate co-substituted hydroxyapatite, having sodium content in the range of 0.25-1.5 wt.% with a 0.25 wt.% step, were prepared by a precipitation-solid state reaction route. Compacts of the powders were sintered in a CO2 flow (4 mL/min) at 1100 ?C for 2 h. The sintered ceramics contained sodium and carbonate ions in the ranges of 0-1.5 wt.% and 1.3-6 wt.%, respectively, which are typical impurity concentrations in biological apatite. A relationship between sodium and carbonate contents and the type of carbonate substitution was found. The total carbonate content progressively increased with the sodium content. The obtained ceramics showed an AB-type carbonate substitution. However, the substitution became more B-type as the sodium content increased. As a result, the carbonation was almost B-type (94 %) for the highest sodium content (1.5 wt.%).

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15

Bensemlali, Meryem, Meryeme Joudi, Hamid Nasrellah, Imad Yassine, Abdellatif Aarfane, Badreddine Hatimi, Houyem Hafdi, Jihane Mouldar, and Mina Bakasse. "One-step synthesis and characterisation of crystalline nano-calcite from phosphogysum by precipitation method." European Physical Journal Applied Physics 97 (2022): 50. http://dx.doi.org/10.1051/epjap/2022220041.

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In the present study, nano-calcium carbonate (NCC) was prepared from phosphogypsum (PG) as waste material from phosphate industry using Na2CO3 and Al(HCO3)3 as carbonates precursors. The physicochemical characteristics of the prepared nano-calcite CaCO3 were studied using various methods, including X-ray diffraction (XRD), scanning electron microscope (SEM), chemical analysis, plasma spectrometry with inductive coupling (ICP), as well as the Bernard calcimeter. The size of the pure nanocalcite particles produced differs according to the nature of the carbonate precursor; they are 51 nm and 68 with the use of sodium carbonate and aluminum hydrogen carbonate, respectively.

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16

Yusuf, Zaki, and John Cameron. "Decarbonization Reactions between Sodium Metaborate and Sodium Carbonate." Industrial & Engineering Chemistry Research 43, no. 26 (December 2004): 8148–54. http://dx.doi.org/10.1021/ie049924b.

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17

Stephen, J. A., C. Pace, J. M. S. Skakle, and Iain R. Gibson. "Comparison of Carbonate Hydroxyapatite with and without Sodium Co-Substitution." Key Engineering Materials 330-332 (February 2007): 19–22. http://dx.doi.org/10.4028/www.scientific.net/kem.330-332.19.

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Carbonate hydroxyapatite (CHA) bioceramics can be synthesised to contain sodium ions as a co-substituted ion, or as sodium-free compositions. It is unclear, however, which composition would produce the optimum biological response. The aim of this study was to find a reliable method to produce sodium co-substituted and sodium-free CHA compositions that would have the same level of carbonate substitution, and to characterise the effects of the two different substitutions on the structure of the CHA samples. After sintering at 900oC in a CO2 atmosphere, all samples contained approximately equal amounts of carbonate groups on the A- and B-sites, as observed by FTIR. The sample produced with NaHCO3 and the sodium-free sample (CHA1) have comparable carbonate contents, whereas the sample produced with Na2CO3 contains significantly more carbonate, probably due to the excess sodium ions allowing more carbonate co-substitution. The sodium-free CHA sample, however, has significantly smaller unit cell parameters compared to both sodium co-substituted CHA samples, and also to HA. This characterisation of the samples shows that the sodium-free CHA sample (CHA1) and the sample produced with NaHCO3 would provide CHA compositions for biological testing with similar carbonate contents and distributions, but with structural differences due to the sodium substitution.

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18

LIANG, YU, SIJIA SUN, HAO DING, and XIFENG HOU. "PREPARATION AND CHARACTERIZATION OF ORGANIC MODIFIED CALCIUM CARBONATE BY SODIUM STEARATE (OR SODIUM OLEATE) USING WET METHOD." Surface Review and Letters 27, no. 10 (July 4, 2020): 1950224. http://dx.doi.org/10.1142/s0218625x1950224x.

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A method of modifying calcium carbonate particles was investigated by coating sodium stearate or sodium oleate on the surface of calcium carbonate by wet method. The results of FTIR, activation and dispersion index, dispersity in kerosene, surface wettability tests and zeta potential tests show that sodium stearate or sodium oleate has successfully coated on the surfaces of calcium carbonate. The main factors were researched and the optimal parameters were obtained for the best modification effect. Compared with common rubber, the modified calcium carbonate added rubber has larger breaking tensile strength (more than 21%) and larger elongation at break (more than 16%). This research provides a feasible way of modifying calcium carbonate for its use as filler in organic matrix, reduces the cost and has a potential application in large-scale production of modified calcium carbonate.

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19

&NA;. "Calcium carbonate/levothyroxine sodium interaction." Reactions Weekly &NA;, no. 1197 (April 2008): 12. http://dx.doi.org/10.2165/00128415-200811970-00037.

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20

Ball, Matthew C., Christine M. Snelling, and Alec N. Strachan. "Dehydration of sodium carbonate monohydrate." Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases 81, no. 8 (1985): 1761. http://dx.doi.org/10.1039/f19858101761.

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21

Gates, Will P., Uzma Shaheen, Terence W. Turney, and Antonio F. Patti. "Cyclic carbonate–sodium smectite intercalates." Applied Clay Science 124-125 (May 2016): 94–101. http://dx.doi.org/10.1016/j.clay.2016.02.005.

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22

Gärtner, Robert S., and Geert-Jan Witkamp. "Mixed solvent reactive recrystallization of trona (sodium sesqui-carbonate) into soda (sodium carbonate anhydrate)." Hydrometallurgy 88, no. 1-4 (August 2007): 75–91. http://dx.doi.org/10.1016/j.hydromet.2007.03.006.

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23

Su, Kun Mei, Zhen Huan Li, Ming Ding, and Xiao Long He. "The Synthesis of Diphenyl Carbonate from Dimethyl Carbonate and Phenol over Modified Organotin Catalysts." Advanced Materials Research 233-235 (May 2011): 124–27. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.124.

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Organotin catalysts were modified with sodium molybdate, sodium tungstate and sodium vanadate, and the modified organotin catalysts displayed high activity in transesterification of dimethyl carbonate (DMC) with phenol into diphenyl carbonate (DPC).

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24

Wang, D., M. Maubert, G. A. Pope, P. J. Liyanage, S. H. Jang, K. A. Upamali, L. Chang, et al. "Reduction of Surfactant Retention in Limestones Using Sodium Hydroxide." SPE Journal 24, no. 01 (November 20, 2018): 92–115. http://dx.doi.org/10.2118/194009-pa.

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Summary Geochemical modeling was used to design and conduct a series of alkaline/surfactant/polymer (ASP) coreflood experiments to measure the surfactant retention in limestone cores using sodium hydroxide (NaOH) as the alkali. Surfactant/polymer (SP) coreflood experiments were conducted under the same conditions for comparison. NaOH has been used for ASP floods of sandstones, but these are the first experiments to test it for ASP floods of limestones. Two studies performed under different reservoir conditions showed that NaOH significantly reduced the surfactant retention in Indiana Limestone. An ASP solution with 0.3 wt% NaOH has a pH of approximately 12.6 at 25°C. The high pH increases the negative surface charge of the carbonate, which favors lower adsorption of anionic surfactants. Another advantage of NaOH is that low concentrations of only approximately 0.3 wt% can be used because of its low molecular weight and its low consumption in limestones. Most reservoir carbonates contain gypsum or anhydrite, and therefore sodium carbonate (Na2CO3) will be consumed by the precipitation of calcium carbonate (CaCO3). As shown in the two studies, NaOH can be used in limestone reservoirs containing gypsum or anhydrite.

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25

Yu, Hai Yan, Shuang Zhang, Wen Fang Wu, Xiao Lin Pan, and Shi Wen Bi. "Effect of Sodium Carbonate Concentration on Leaching Property of Sintered Clinkers with Low A/S Ratio." Advanced Materials Research 581-582 (October 2012): 847–50. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.847.

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The effect of sodium carbonate concentration on alumina leaching of low A/S ratio clinkers and SiO2 concentration in leached liquor was studied in this paper. The clinker with the Al2O3/SiO2 mass ratio of 1.0 (the molar ratios of CaO/SiO2 and Na2O/Al2O3 are 2.0 and 1.05) was sintered at 1230°C using AR reagents. The alumina leaching rate and SiO2 concentration in leached liquor increase with the increase of sodium carbonate concentration, and the alumina leaching rate reaches its maximum of 96.36% when the sodium carbonate concentration is 15g/L. The results of XRD indicate that sodium carbonate can inhibit the formation of hydrogarnet, and there is almost no formation of hydrogarnet when the sodium carbonate concentration is 15g/L.

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26

Zhang, Jieyuan, Quoc P. Nguyen, Adam Flaaten, and Gary A. Pope. "Mechanisms of Enhanced Natural Imbibition With Novel Chemicals." SPE Reservoir Evaluation & Engineering 12, no. 06 (November 17, 2009): 912–20. http://dx.doi.org/10.2118/113453-pa.

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Summary A large body of literature has reflected an extensive experimental study of natural imbibition driven by local capillary pressures at high interfacial tension (IFT). However, water imbibition induced by emulsification at low IFT is not well understood. Recently, anionic surfactants have been shown to induce imbibition in mixed- and oil-wet carbonates. Sodium carbonate has been used to reduce the surfactant adsorption. However, calcium and other divalent cations can cause precipitation of the alkali unless soft water is used. This is a significant limitation of sodium carbonate. The present research both advances our understanding of the use of chemicals to enhance oil recovery (EOR) from fractured carbonate reservoirs and indicates how the process can be optimized using novel chemicals. This research applies to the improvement of oil recovery from mixed- and oil-wet fractured carbonate reservoirs. We show how to select and evaluate new chemicals as natural imbibition enhancers in carbonate rocks. A novel experimental method has also been developed to quantify the significance of capillary and emulsification driven imbibition because of the presence of the chemical imbibition enhancers. An in situ imbibition profile was visualized using a computed tomography (CT) X-ray scanning technique. The results show that formation of microemulsion strongly promotes water imbibition. The rate was highest for Winsor Type II microemulsion and lowest for Winsor Type I microemulsion. The alkalis exhibited a striking imbibition enhancement driven mainly by alteration of capillary pressure. The performance of the imbibition enhancers was found to be consistent for different core-plug sizes and boundary conditions. A novel alkali has been tested that shows a high tolerance for hardness and, thus, may be a good alternative to sodium carbonate under some conditions. The application of low-cost chemicals to EOR from fractured carbonates is an extremely significant development owing to the vast volumes of oil in such reservoirs and the lack of practical alternative methods of recovering such oil.

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27

Wongkeo, Watcharapong. "Effect of Calcium Carbonate on Compressive Strength and Physical Properties of Alkali-Activated Lightweight Concrete." Key Engineering Materials 751 (August 2017): 550–55. http://dx.doi.org/10.4028/www.scientific.net/kem.751.550.

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This study presents the compressive strength and physical properties of alkali-activated lightweight concrete. Alkali-activated lightweight concrete was synthesized with fly ash, calcium carbonate and sodium hydroxide solution. Calcium carbonate was designed to replace part of fly ash at 5 and 10 wt.%. Sodium hydroxide solution at 5, 7.5 and 10 M was used as a liquid solution. Liquid to ash ratio (L/A ratio) at 0.45 was designed and aluminium powder was used as a foaming agent. The results showed that, the compressive strength of alkali-activated lightweight concrete made with fly ash was increased with NaOH concentration increased. The maximum compressive strength at 6.0 MPa was obtained from 10M NaOH mixture. For fly ash-calcium carbonate system, the compressive strength of lightweight concrete was improved when containing calcium carbonated, especially at 5 and 7.5 M NaOH mixtures. The maximum of compressive strength at 8.1 MPa and bulk density were obtained from the 5 wt.% calcium carbonated with 10M NaOH mixture. Water absorption and voids of all mixtures trend to decrease with increased NaOH concentration. XRD showed the sodium aluminum silicate hydrated as an alkali-activated product and composed of Si/Al atomic ratio at 2.1 and Na/Al atomic ratio at 1.4, respectively. Bulk density and compressive strength of alkali-activated lightweight concrete made with both fly ash and fly ash-calcium carbonated were acceptable in accordance with the specified criteria of TIS 2601. The well pore structure distribution of alkali-activated lightweight concrete was acceptable.

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28

Burk, J. H. "Comparison of Sodium Carbonate, Sodium Hydroxide, and Sodium Orthosilicate for EOR." SPE Reservoir Engineering 2, no. 01 (February 1, 1987): 9–16. http://dx.doi.org/10.2118/12039-pa.

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29

St. John, Steven J., Anya M. McBrayer, and Erin E. Krauskopf. "Sodium Carbonate is Saltier Than Sodium Chloride to Sodium-Depleted Rats." Chemical Senses 42, no. 8 (July 17, 2017): 647–53. http://dx.doi.org/10.1093/chemse/bjx043.

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30

Wang, Jing Chen, Feng Xia Cui, and Tao Li. "Optimization of Synthesis Process for Sodium Ascorbate." Advanced Materials Research 550-553 (July 2012): 10–15. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.10.

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With 2-keto-L-gulonic acid(2KLG) and methanol as raw materials, 98% concentrated sulfuric acid as catalyst, the methyl esterification reaction is occurred. Then with sodium carbonate as a transforming agent, a conversion reaction sodium carbonate is obtained. In this experiment, the effects of reaction time, reaction temperature and reactant ratio on conversion rate of sodium ascorbate were studied. The results showed that sodium carbonate as the reactant of lactonization reaction can effectively shorten the reaction time and improve reaction yield. By experiment under the optimum process conditions: the reaction temperature is 65 °C, reaction time is 150 minutes and the molar ratio of 2-keto-L-gu methyl to sodium carbonate is 1:0.6, the conversion rate reaches 98 % and the effect is better than with sodium bicarbonate as transforming agent.

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31

Mulopo, J., and V. Radebe. "Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines." Water Science and Technology 66, no. 6 (September 1, 2012): 1296–300. http://dx.doi.org/10.2166/wst.2012.322.

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The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO3 recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO3 recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO3.

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32

Milosavljevic, Milutin, Ljiljana Babicev, Svetlana Belosevic, Dunja Danicic, Milena Milosevic, Jelena Rusmirovic, and Aleksandar Marinkovic. "Innovative environmentally friendly technology for copper(II) hydroxide production." Chemical Industry 72, no. 6 (2018): 363–70. http://dx.doi.org/10.2298/hemind180630023m.

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The innovative laboratory procedure for the synthesis of copper(II) hydroxide in the form of the aqueous suspension was developed. The reaction mechanism consists of the reaction between copper(II) sulphate pentahydrate and sodium carbonate by successive ion exchange of carbonate ions with the hydroxide ones in a multistep process. Production of copper(II) carbonate and sodium sulphate by reacting of copper(II) sulphate with sodium carbonate was followed by addition of sodium hydroxide solution whereby the product, copper(II) hydroxide, was obtained by releasing an equimolar amount of sodium carbonate. It was determined that, the equimolar reaction of copper(II) sulphate and sodium hydroxide lead to the maximal reactants exploitation. Sodium phosphate, formed in the final process stage by addition of 10 % phosphoric acid solution, acted as a copper(II) hydroxide stabilizer. High yield of the product was obtained by optimizing the synthesis parameters: reaction time, molar ratio of reactants and the reaction temperature. The obtained product was formulated to obtain a commercial product, which is used as a fungicide and bactericide.

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33

Gold, Marvin. "A simple quantitative synthesis: Sodium chloride from sodium carbonate." Journal of Chemical Education 65, no. 8 (August 1988): 731. http://dx.doi.org/10.1021/ed065p731.

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34

Chibowski, Emil, Lucyna Hołysz, Aleksandra Szcześ, and Marcin Chibowski. "Precipitation of calcium carbonate from magnetically treated sodium carbonate solution." Colloids and Surfaces A: Physicochemical and Engineering Aspects 225, no. 1-3 (September 2003): 63–73. http://dx.doi.org/10.1016/s0927-7757(03)00133-x.

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35

Wang, Yuli, Fengxia He, Junjie Wang, and Qianku Hu. "Comparison of Effects of Sodium Bicarbonate and Sodium Carbonate on the Hydration and Properties of Portland Cement Paste." Materials 12, no. 7 (March 28, 2019): 1033. http://dx.doi.org/10.3390/ma12071033.

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Carbonates and bicarbonates are two groups of accelerators which can be used in sprayed concrete. In this study, the effects of the two accelerators sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) (0%, 1%, 2%, 3%, and 4% by weight of ordinary Portland cement OPC) on the properties of OPC paste were compared. The results show that both of them could accelerate the initial and final setting time of OPC paste, but the effect of the two accelerators on the compressive strength were different. After 1 day, sodium bicarbonate at 3% had the highest strength while sodium carbonate at 1% had the highest strength. After 7 days, both of the two accelerators at 1% had the highest compressive strength. After 28 days, the compressive strength decreased with the increase of the two. The improved strength at 1 and 7 days was caused by the accelerated formation of ettringite and the formation of CaCO3 through the reactions between the two with portlandite. The decrease of strength was caused by the Na+ could reduce the adhesion between C-S-H gel by replacing the Ca2+. NaHCO3 was found be a better accelerator than Na2CO3.

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36

Ren, Fu Zeng, Yang Leng, and Xiong Lu. "Ab Initio Simulations on the Carbonated Apatite Structure." Key Engineering Materials 529-530 (November 2012): 1–6. http://dx.doi.org/10.4028/www.scientific.net/kem.529-530.1.

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ab initio simulations were employed to investigate the crystal structure of carbonated apatite (CAp). Two possible sites for the carbonate ions in the apatite lattice were considered: carbonate substituting for OH-ion (type-A) and for PO43-ion (type-B). A combined type-AB substitution was also proposed and numerous possible charge compensation mechanisms were treated. The results show that the most stable type-A CAp had its carbonate triangular plane almost parallel to c-axis, making an angle of about 2° at z = 0.46. In the most stable type-B CAp structure, the nearest Ca (2) ion was replaced by a sodium ion and the carbonate group was lying almost flat inb/c-plane. Of all the models considered, mixed substitution type-AB where two carbonate ions replacing one phosphate group and one hydroxyl group shows the most stable structure.

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37

Adesina, Adeyemi. "Influence of various additives on the early age compressive strength of sodium carbonate activated slag composites: An overview." Journal of the Mechanical Behavior of Materials 29, no. 1 (September 22, 2020): 106–13. http://dx.doi.org/10.1515/jmbm-2020-0011.

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AbstractThe use of sodium carbonate as an alkali activator for slag to produce alkali-activated slag is promising due to its sustainable, economic and user-friendly properties. However, the lower early age performance of composites made with such binder has limited its use especially in applications where higher early age is required. Hence, in order to propel the application of this sustainable binder, it is imperative to find ways in which the early age performance can be enhanced without having a detrimental effect on later age performance. One of the effective and sustainable ways to enhance the early age strength of sodium carbonate activated slag is by incorporation of various additives as partial replacement of sodium carbonate on/and slag. In order to propel more application of sodium carbonate slag for various applications, this current study was undertaken. In this paper, an overview of the types of various additives that can be used to enhance the early age compressive strength of sodium carbonate activated slag composites was discussed. The mechanism and dosage of each of the additives were briefly discussed alongside the limitation and advantages of the additives. Findings from this overview showed that the early age compressive strength of sodium carbonate activated slag can be enhanced with the use of additives such as calcium oxide, calcium hydroxide, Portland cement, sodium hydroxide and sodium silicate.

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38

Liu, Kai Qiang, Hui Tang, Yan Nian Rui, and Guo Qiang Chen. "Alkali Resistance of the Silk/PLA Mixture." Advanced Materials Research 441 (January 2012): 687–90. http://dx.doi.org/10.4028/www.scientific.net/amr.441.687.

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As a new textile material, silk/PLA mixture combines the outstanding characteristics of silk and PLA fibers, but this mixture is subjected to some problems owing to the poor alkali resistance of PLA fiber during the pretreatment and reactive dyeing processes. In the present work, the alkali resistance of silk/PLA mixture was tested with three alkalis, namely sodium hydroxide, sodium carbonate and sodium bicarbonate. It was found that silk component was less influenced by sodium carbonate and sodium bicarbonate, whereas PLA component was more or less influenced by three alkalis. Silk/PLA mixture showed low weight loss after sodium carbonate and sodium bicarbonate treatment, but had very high weight loss after sodium hydroxide treatment. 10 g/L sodium carbonate and 3 g/L sodium hydroxide resulted in the obvious changes in the morphological structure of PLA. After the alkaline treatment, the IR spectra of PLA treated with 3 g/L alkali displayed great variations, and the intensity of the peak at 3429.3 cm-1 increased with the strength of alkalis, showing that the partially hydrolysis of PLA occurred.

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39

Palou, Lluís, Joseph L. Smilanick, Josep Usall, and Inmaculada Viñas. "Control of Postharvest Blue and Green Molds of Oranges by Hot Water, Sodium Carbonate, and Sodium Bicarbonate." Plant Disease 85, no. 4 (April 2001): 371–76. http://dx.doi.org/10.1094/pdis.2001.85.4.371.

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Control of citrus blue mold, caused by Penicillium italicum, was evaluated on artificially inoculated oranges immersed in water at up to 75°C for 150 s; in 2 to 4% sodium carbonate (wt/vol) at 20 or 45°C for 60 or 150 s; or in 1 to 4% sodium bicarbonate at room temperature for 150 s, followed by storage at 20°C for 7 days. Hot water controlled blue mold at 50 to 55°C, temperatures near those that injured fruit, and its effectiveness declined after 14 days of storage. Sodium carbonate and sodium bicarbonate were superior to hot water. Temperature of sodium carbonate solutions influenced effectiveness more than concentration or immersion period. Sodium carbonate applied for 150 s at 45°C at 3 or 4% reduced decay more than 90%. Sodium bicarbonate applied at room temperature at 2 to 4% reduced blue mold by more than 50%, while 1% was ineffective. In another set of experiments, treatments of sodium bicarbonate at room temperature, sodium carbonate at 45°C, and hot water at 45°C reduced blue mold incidence on artificially inoculated oranges to 6, 14, and 27%, respectively, after 3 weeks of storage at 3°C. These treatments reduced green mold incidence to 6, 1, and 12%, respectively, while incidence among controls of both molds was about 100%. When reexamined 5 weeks later, the effectiveness of all, particularly hot water, declined. In conclusion, efficacy of hot water, sodium carbonate, and sodium bicarbonate treatments against blue mold compared to that against green mold was similar after storage at 20°C but proved inferior during long-term cold storage.

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40

Stejskalová, Květoslava, Pavel Bach, Erich Lippert, and Karel Mocek. "Effects of the Gas Phase Composition and Genesis of the Active Sodium Carbonate on Its Reactivity Towards Gaseous Mixture SO2 + NOx." Collection of Czechoslovak Chemical Communications 62, no. 3 (1997): 387–91. http://dx.doi.org/10.1135/cccc19970387.

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The reactivity of the solid active sodium carbonate towards gaseous mixture SO2 + NOx has been measured in the dependence on oxygen and carbon dioxide contents and on genesis of the solid substance. The fixed bed flow reactor working under integral conditions has been used. It was found that the reactivity of the active sodium carbonate of the 1st generation towards gaseous mixture SO2 + NOx is higher than the reactivity of the active sodium carbonate of the 2nd generation. In the temperature range of 130-180 °C the partial pressures of oxygen and carbon dioxide have no decisive influence on the reactivity of the active sodium carbonate of the 1st generation.

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41

Rebellato, Ana Paula, Priscila Ferreira Tavares, Guilherme Neves Trindade, Juliana A. Lima Pallone, Pedro H. Campelo, and Maria Teresa Pedrosa Silva Clerici. "Alkaline instant noodles: use of alkaline salts to reduce sodium and assessment of calcium bioaccessibility." Research, Society and Development 10, no. 2 (February 27, 2021): e51210212778. http://dx.doi.org/10.33448/rsd-v10i2.12778.

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Instant noodles originated in eastern nations and have been accepted due to its practicality and low cost. However, its high sodium content can lead to health problems. The present study aimed to reduce sodium and increase calcium levels in noodles. A control (N1: K2CO3+ Na2CO3) and three treatments with the addition of calcium carbonate in combination with alkaline salts such as potassium and sodium carbonates (N2: K2CO3+ CaCO3; N3: Na2CO3+ CaCO3; and N4: CaCO3) were studied. Two hydration methods were investigated, and the technological characterization and the calcium bioaccessibility of the different noodle formulations were determined. N4 did not fit into the alkaline noodle category due to its neutral pH. N2 and N4 showed a sodium reduction of around 28% and a significant increase in calcium content, with higher bioaccessible calcium. Significant changes were observed for the noodles made with the addition of different alkaline salts, with a light-yellow color and better texture than the control, which can be a positive aspect, once products with reduced nutrients usually present differentiated coloring. Therefore, the use of calcium carbonate may be a promising alternative to increase Ca intake and to reduce the sodium content of instant noodles.

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42

Sokolář, Radomír. "Dispersants for Dual Binding System Kaolin - Calcium Aluminate Cement." Advanced Materials Research 1124 (September 2015): 10–15. http://dx.doi.org/10.4028/www.scientific.net/amr.1124.10.

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Calcium aluminate cement CAC is able to increase strength of green body distintly. Influence of typical ceramic dispersants – sodium hexametaphosphate SHMP, sodium carbonate SC and sodium silicate (water glass) SWG – on the rheological properties (viscosity) of calcium aluminate cement – kaolin slurries with different ratio between CAC and kaolin was determined. In all cases sodium carbonate is the most effective dispersant but deflocculation is not very intensive – decrease of torque during the rotational viscometer test was not higher than 15 % (from 68,8 N.mm to 58.3 N.mm for ratio 1:1 of CAC:kaolin suspension when 0,06 %-wt of sodium carbonate was used).

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43

Zulhan, Zulfiadi, Rifda Dinillah, Toto Yulianton, Imam Santoso, and Taufiq Hidayat. "Carbothermic Reduction of Ilmenite Concentrate with Sodium Carbonate Additive to Produce Iron Granules and High Titania Containing Slag." Metals 12, no. 6 (June 3, 2022): 963. http://dx.doi.org/10.3390/met12060963.

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The influences of heating pattern and sodium carbonate addition on the carbothermic reduction of ilmenite concentrate have been experimentally studied. The experiments were carried out using isothermal–gradient temperature technique between 1000 °C and 1500 °C with different temperature profiles for a total reduction time between 110 and 160 min. The sodium carbonate was varied between 0 to 60 wt%. It was found that the temperature profile and sodium carbonate addition play an important role on the separation between metallic iron granule and titania rich slag. The optimum condition was achieved at initial and final reduction temperatures of 1300 °C and 1500 °C, respectively, with sodium carbonate addition of 30 wt%. At the optimum condition, the iron recovery was 97.1% and the solidified slag contained titanium pentoxide (Ti3O5), anatase (TiO2), and sodium titanium dioxide.

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44

Hill, Ronald. "Carbonate Effects on Sodium Hydroxide Dosage." Proceedings of the Water Environment Federation 2000, no. 3 (January 1, 2000): 1053–71. http://dx.doi.org/10.2175/193864700785303105.

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45

Toturbiev, B. D., S. A. Mamaev, and A. B. Toturbiev. "POLYSILICATE SODIUM COMPOSITIONS FROM CARBONATE ROCKS." PROCEEDINGS OF INSTITUTE OF GEOLOGY DAGESTAN SCIENTIFIC CENTER OF RAS, no. 2 (2021): 75–82. http://dx.doi.org/10.33580/2541-9684-2021-85-2-75-82.

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46

Chuealee, Rabkwan, Timothy S. Wiedmann, and Teerapol Srichana. "Thermotropic behavior of sodium cholesteryl carbonate." Journal of Materials Research 24, no. 1 (January 2009): 156–63. http://dx.doi.org/10.1557/jmr.2009.0027.

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Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.

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47

Nalewaja, John D., Frank A. Manthey, Edward F. Szelezniak, and Zbigniew Anyska. "Sodium Bicarbonate Antagonism of Sethoxydim." Weed Technology 3, no. 4 (December 1989): 654–58. http://dx.doi.org/10.1017/s0890037x0003298x.

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Research was conducted to determine the influence of water carrier quality on grass control from sethoxydim. Water from a well near Halliday, ND, where sethoxydim failed to control grasses, contained 650 mg/L sodium and 1650 mg/L bicarbonate. Both sodium bicarbonate and sodium carbonate when included in the sethoxydim spray reduced grass species control in the greenhouse and field. Sodium carbonate in the spray generally was more antagonistic than sodium bicarbonate to sethoxydim toxicity to grasses. The antagonism from sodium bicarbonate at 6000 mg/L was overcome by diammonium sulfate or ammonium nitrate at 2.8 kg/ha or a 28% nitrogen liquid fertilizer at 9.4 L/ha in the sethoxydim spray. These compounds also overcame sodium carbonate and partly overcame the antagonism of sethoxydim by bentazon. Three commercial adjuvants for use with sethoxydim differed in their effect on wheat and oats control with sethoxydim alone or with bentazon.

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48

Jing, Kai, Yun Zhang, and Xiang Rong Wang. "Study on the Structure and Properties of Natural Color Silk Treated by Alkali." Advanced Materials Research 175-176 (January 2011): 760–64. http://dx.doi.org/10.4028/www.scientific.net/amr.175-176.760.

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The natural color silk has been treated by sodium hydroxide and sodium carbonate，and the structure, crystallize and mechanical properties of the treated natural color silk were studied. The results showed that the structure of natural color silk was not changed and the degree of crystallinity decreased; the crystallinity of un-treated natural color silk was 44.4%, while the crystallinities of natural color silk treated by sodium hydroxide and sodium carbonate were 35.2% and 43.6%, respectively. The breaking tenacity and the breaking elongation of natural color silk treated by sodium hydroxide dropped dramatically and the Young’s Modulus declined; but these properties of natural color silk were not changed significantly after being treated by sodium carbonate.

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49

Shaikh, Amjad A., Agba D. Salman, Steve Mcnamara, Gill Littlewood, Fraser Ramsay, and Michael J. Hounslow. "In Situ Observation of the Conversion of Sodium Carbonate to Sodium Carbonate Monohydrate in Aqueous Suspension." Industrial & Engineering Chemistry Research 44, no. 26 (December 2005): 9921–30. http://dx.doi.org/10.1021/ie0505211.

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50

Mitchell, R. H. "An ephemeral pentasodium phosphate carbonate from natrocarbonatite lapilli, Oldoinyo Lengai, Tanzania." Mineralogical Magazine 70, no. 2 (April 2006): 211–18. http://dx.doi.org/10.1180/0026461067020326.

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AbstractLapilli formed by a Strombolian eruption are associated with the formation of a large lava flow of natrocarbonatite on or about 21–22 July, 2000 at Oldoinyo Lengai volcano, Tanzania. Fresh lapilli consist of vesicular natrocarbonatite similar to that occurring in rapidly quenched lavas. The lapilli were altered at low temperature (<50°C) by degassing to aggregates of sodian sylvite, potassian halite, trona, thermonatrite and a novel F-bearing sodium phosphate-carbonate. The latter is considered to be a new mineral as it has a composition (Na5–4.5PO4(CO3,F,Cl) that is not similar to that of nahpoite (Na2HPO4), dorfmanite [Na2(PO3OH).2H2O] or natrophosphate [Na7(PO4)2F.19H2O]. However, in common with these minerals, it is ephemeral and undergoes rapid decomposition under normal atmospheric conditions. The sodium phosphate-carbonate and associated halide-sodium carbonate assemblages are considered to be a part of a previously unrecognized hyperagpaitic assemblage forming as sublimates at Oldoinyo Lengai.

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