A study on the influence of sodium carbonate concentration on the synthesis of high Mg calcites

CrystEngComm ◽  
2016 ◽  
Vol 18 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Heng Yang ◽  
Shiqiang Chai ◽  
Yuzhe Zhang ◽  
Yurong Ma
Keyword(s):  
Sodium Carbonate ◽  
Calcium Ions ◽  
Hydrothermal Process ◽  
Organic Additives ◽  
Amorphous Precursor ◽  
Molar Ratios ◽  
Carbonate Concentration ◽  
Pure Phase

High Mg calcites in pure phase with controlled magnesium contents were synthesized by using amorphous precursor through a hydrothermal process in the absence of organic additives. It is found that the Mg contents in the high Mg calcites increase with the increase of the molar ratios of carbonate and calcium ions in the mother solutions.

Effect of Sodium Carbonate Concentration on Leaching Property of Sintered Clinkers with Low A/S Ratio

2012 ◽  
Vol 581-582 ◽  
pp. 847-850
Author(s):  
Hai Yan Yu ◽  
Shuang Zhang ◽  
Wen Fang Wu ◽  
Xiao Lin Pan ◽  
Shi Wen Bi
Keyword(s):  
Sodium Carbonate ◽  
Leaching Rate ◽  
Mass Ratio ◽  
Sio2 Concentration ◽  
Molar Ratios ◽  
Carbonate Concentration ◽  
No Formation

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.

scholarly journals Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

2016 ◽  
Vol 20 (3) ◽  
pp. 985-991
Author(s):  
Zhi Liu ◽  
Yuqin Wan ◽  
Hao Dou ◽  
Ji-Huan He
Keyword(s):  
Formic Acid ◽  
Silk Fibroin ◽  
Sodium Carbonate ◽  
High Efficiency ◽  
Lithium Bromide ◽  
Solution Properties ◽  
Acid System ◽  
Acid Dissolution ◽  
Carbonate Concentration ◽  
Degumming Process

Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

scholarly journals Effect of Sodium Carbonate Concentration in Calgon on Hydrometer Analysis Results

2018 ◽  
Author(s):  
Arshdeep Kaur ◽  
George C. Fanourakis
Keyword(s):  
Sodium Carbonate ◽  
Clay Content ◽  
The Other ◽  
Sodium Hexametaphosphate ◽  
Carbonate Content ◽  
Fine Grained ◽  
Carbonate Concentration ◽  
Dispersing Agent ◽  
Effective Combination ◽  
Dispersing Agents

Calgon (a combination of sodium hexametaphosphate and sodium carbonate) has proved to be the most effective dispersing agent in determining the grain size distribution of fine-grained soils by means of the hydrometer analysis. Previous research on the effect of the sodium hexametaphosphate content of dispersing agents on the clay contents showed that the addition of sodium carbonate to sodium hexametaphosphate increases its dispersing effectiveness. Hence, Calgon 35:7 was used /recommended by many researchers/methods and proved to be the most effective dispersing agent. Although previous work focusing on the effect of varying the concentration of sodium hexametaphosphate in Calgon has been reported, the effect of the concentration of sodium carbonate in Calgon has not been assessed and reported. For this reason, in this investigation a series of hydrometer test analyses were conducted using the 152H and ASTM 152H: E100 hydrometers with Calgon in ratios of 35:0, 35:20 and 35:30.  It was observed that with any increase in sodium carbonate content beyond 7 grams, the percentage clay content actually decreased tremendously in the case of hydrometer 152H. However, for the other hydrometer, Calgon (35:0) proved to be most effective combination. Thus, the increase in the sodium carbonate content in Calgon, beyond 7 g/ litre, is not recommended.

Preparation and Characterization of Ti-SBA-15 Mesoporous Materials with Varying Si/Ti Molar Ratios

2012 ◽  
Vol 482-484 ◽  
pp. 985-988
Author(s):  
Qiu Ying Huang ◽  
Wei Liu ◽  
Wen Hao Ye ◽  
Xiu Cheng Zheng
Keyword(s):  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
Catalytic Efficiency ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Good Catalytic Activity ◽  
Epoxidation Of Cyclohexene

Ti-SBA-15 mesoporous materials with different Si/Ti molar ratios were synthesized via a hydrothermal process and characterized by using various techniques. The effect of Si/Ti molar ratios in the gels on the structure and catalytic efficiency in epoxidation of cyclohexene was discussed in details. The results showed that all the Ti-SBA-15 materials retained SBA-15 mesoporous structure and exhibited good catalytic activity. Furthermore,the sample prepared with Si/Ti =50 exhibited the best catalytic performance under the reaction conditions.

Tl2Ba2CaCu2O8: STRUCTURE AND SUPERCONDUCTIVITY

1988 ◽  
Vol 02 (05) ◽  
pp. 681-687 ◽  
Author(s):  
A. MAIGNAN ◽  
C. MICHEL ◽  
M. HERVIEU ◽  
C. MARTIN ◽  
D. GROULT ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Ions ◽  
Structural Model ◽  
High Resolution Electron Microscopy ◽  
Extended Defects ◽  
Superconducting Properties ◽  
Local Composition ◽  
X Ray ◽  
Resolution Electron ◽  
Pure Phase

Tl 2 Ba 2 CaCu 2 O 8 has been synthesized as a pure phase by reaction in sealed quartz tube. The structural model of this oxide has been established from X-ray diffractograms and high resolution electron microscopy. This tetragonal structure (a=3.860 Å, c=29.388 Å, space group I4/mmm) can be described as formed of [ Ba 2Tl2Cu2 O 8]∞ layers interleaved with calcium ions. These layers are themselves described as the intergrowth of sodium chloride type [TIO] ∞ layers of corner-sharing pyramids [ BaCuO 3]∞ leading to the formulation [( BaCuO 3)2 (TIO) 2]∞. Such a perfect structure Tl2 Ba 2 CaCu 2O8, which contains only Cu(II) cannot be at the origin of the superconductivity at 110K. The superconducting properties may in fact be explained by the observation by HREM of extended defects of local composition “ TlBa 2 CaCu 2O7” for which a structural model is proposed. In a more general way the creation of thallium deficiency, according to the formulation Tl2−x Ba 2 CaCu 2 O 8 could be at the origin of superconductivity.

scholarly journals Optimization of Gas-Water Absorption Equilibrium of Carbon Dioxide for Algae Liquors: Selection of Alkaline Buffering Chemicals

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Wen-Hsi Cheng ◽  
Ming-Shean Chou
Keyword(s):  
Carbon Dioxide ◽  
Sodium Carbonate ◽  
Egeria Densa ◽  
Optimal Conditions ◽  
Liquid Equilibrium ◽  
Ph Values ◽  
Carbonate Concentration ◽  
Different Temperatures ◽  
The Mean ◽  
Selection Of

The apparent Henry’s Law constant (H′), which quantifies the concentration partition of a gas-liquid equilibrium of carbon dioxide (CO2), is used to optimize the absorption of carbon dioxide in algae liquors. The values ofH′were examined under various conditions: in water at different temperatures (27 and 37°C), in alkaline buffering chemicals (sodium hydroxide (NaOH) and sodium carbonate (Na2CO3)), and in aquatic algae plants (Egeria densaandAnubias barteri nana). The optimal conditions for CO2absorption can be obtained by controlling the aqueous pH values (around weak alkalinity with pH 9-10) using sodium carbonate as an alkaline buffering chemical at 27°C, yielding exactH′values of around 16.3–21.3 atm/M, which were obtained from the mean gaseous CO2concentration of 803 ppm and the total aqueous carbonate concentration of 4.085 mg/L. The experimental results reveal that an alkaline buffering compound, sodium carbonate, can be added to water to maintain a constant aqueous alkalinity enough for the fixation of carbon dioxide by the photosynthesis of green algae in a photobioreactor.

scholarly journals Effects of Si/Al Ratios on the Bulk-Type Zeolite Formation Using Synthetic Metakaolin-Based Geopolymer with Designated Composition

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1310
Author(s):  
Guoru Ma ◽  
Chengying Bai ◽  
Meirong Wang ◽  
Peigang He
Keyword(s):  
Phase Composition ◽  
Hydrothermal Treatment ◽  
Hydrothermal Process ◽  
Molar Ratios ◽  
Zeolite Formation ◽  
Fixed Composition ◽  
Type Zeolite ◽  
Influence Of Impurities ◽  
Geopolymer Composites

In this paper, synthetic metakaolin with fixed composition (Al2O3·2SiO2) was produced by a simple chemosynthetic route. The chemosynthetic metakaolin can eliminate the influence of impurities in metakaolin from natural kaolin minerals. The synthetic metakaolin together with NaOH and SiO2-sol were used to prepare Na-based geopolymer precursors with various molar ratios of Si/Al. The molar ratios of Si/Al from 1 to 2 were tailored by adding different contents of SiO2-sol. Zeolite/geopolymer composites or monolith-type zeolite were successfully fabricated from synthetic metakaolin-based geopolymer through a hydrothermal process. The effects of Si/Al ratios on the phase composition and microstructure of the produced zeolite/geopolymer composites or zeolites were studied. The results proved that the composition of synthetic metakaolin and geopolymer precursors can be facilely tuned, and the monolithic geopolymer precursors can be mostly, or even totally, transformed into zeolite after hydrothermal treatment.

Nitridsulfidhalogenide der leichten Lanthanide vom Typ M6N3S4X (M = La - Nd; X = Cl, Br) mit ausgeordneten Sulfid- und Halogenid-Lagen / Nitride Sulfide Halides of the Light Lanthanides with the Formula Type M6N3S4X (M = La - Nd; X = Cl, Br) with Ordered Sulfide and Halide Positions

2002 ◽  
Vol 57 (10) ◽  
pp. 1079-1084 ◽  
Author(s):  
Falk Lissner ◽  
Thomas Schleid
Keyword(s):  
Double Chain ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
X Ray ◽  
Molar Ratios ◽  
Fast Reactions ◽  
Closest Packing ◽  
Pure Phase ◽  
Light Lanthanides ◽  
Formula Type

AbstractThe oxidation of the light lanthanides (M = La - Nd) with sulfur and NaN3 in the presence of the tribromides MBr3 yields bromine-poor nitride sulfide bromides with the composition M6N3S4Br when appropriate molar ratios of the reactants are used. Additional NaBr as a flux secures complete and fast reactions (7 d) at 850 °C in evacuated silica tubes as well as singlecrystals of the pure phase (brownish needles). The orthorhombic crystal structure (Pnma, Z = 4) was determined from single crystal X-ray data for La6N3S4Br (a = 1159.23(9), b = 410.85(3), c = 2765.6(2) pm), Ce6N3S4Br (a = 1152.31(9), b = 407.52(3), c = 2747.4(2) pm), Pr6N3S4Br (a = 1145.42(9), b = 404.21(3), c = 2729.3(2) pm), and Nd6N3S4Br (a = 1138.59(9), b = 400.94(3), c = 2711.3(2) pm). Six crystallographically different M3+ cations are present, two of them (M1 and M2) build up chain I (1∝ {[NM2]3+}) by cis-edge connection of [NM4] tetrahedra. The four remainders (M3 - M6) arrange as pairs [N2M6] of edge-shared [NM4] units which are further connected via four vertices to form a double chain (chain II = 1∝ {[N2M4]6+}). Bundled along [010] like a closest packing of rods, both types of chains are commensurate in translation and held together by one Br- and four S2- anions which, in contrast to an earlier work on the pseudo-isotypic chloride analogues M6N3S4Cl (M = La - Nd), are perfectly ordered.

scholarly journals Preparation of γ-Fe2O3/Ni2O3/FeCl3(FeCl2) Composite Nanoparticles by Hydrothermal Process Useful for Ferrofluids

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Qingmei Zhang ◽  
Jian Li ◽  
Hua Miao ◽  
Jun Fu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Composite Nanoparticles ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
Outermost Layer ◽  
X Ray ◽  
Specific Saturation Magnetization ◽  
Transmission Electron

Using a hydrothermal process in FeCl2 solution, γ-Fe2O3/Ni2O3/FeCl3(FeCl2) composite nanoparticles were obtained from the FeOOH/Ni(OH)2 precursor prepared by coprecipitation. The precursor and the as-prepared nanoparticles were investigated by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), energy disperse X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The experimental results showed that the paramagnetic amorphous precursor, in which Ni(OH)2 is formed outside FeOOH, is transformed to ferrimagnetic γ-Fe2O3/Ni2O3 composite when it is processed in FeCl2 solution (0.25, 0.50, 1.00 M) in an autoclave at 100°C for 1 hr. In addition, the dismutation reaction of FeCl2 produces FeCl3 and Fe. Some FeCl3 and little FeCl2 can be absorbed to form γ-Fe2O3/Ni2O3/FeCl3(FeCl2) composite nanoparticles in which Ni2O3 forms outside the γ-Fe2O3 core and the outermost layer is FeCl3 (FeCl2). The content of FeCl3 (FeCl2) in the particles increased, and the magnetization of the particles decreased with the concentration of FeCl2 solution increasing in the hydrothermal process. The FeCl3 (FeCl2) surface is chemically passive and nonmagnetic (paramagnetic). Accordingly, the composite nanoparticles are chemically stable, and their aggregation is prevented. The specific saturation magnetization of such composite nanoparticles can get to 57.4–62.2 emu/g and could be very suitable for synthesizing ferrofluids.

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