Synthesis of Precipitate Calcium Carbonate with Variation Morphology from Limestone by Using Solution Mixing Method

2019 ◽  
Vol 966 ◽  
pp. 200-203
Author(s):  
Zaenal Arifin ◽  
Triwikantoro ◽  
Bintoro Anang Subagyo ◽  
Mochamad Zainuri ◽  
Darminto

Abstract. In this study, the CaCO3 powder has been successfully synthesized by mixing CaCl2 from natural limestone and Na2CO3 in the same molar ratio. The mixing process of solutions was carried out by employing the molar contents of 0.125, 0.25, 0.375 and 0.5M at varying temperatures of 30, 40, 60 and 80ᴼC. The produced CaCO3 microparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The highest content of aragonite phase with morphology rod-like of the samples is around 29 wt%, resulting from the process using solution of 0.125 M at 80 ᴼC. While at 30 ᴼC and 40 ᴼC produced 100 wt% calcite phase.

2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11527
Author(s):  
Pablo Santana ◽  
Dalila Aldana Aranda

The microstructure and nanostructure of nacre in Pteria colymbus were studied with high-resolution field emission scanning electron microscopy (FESEM). The tablets were found to be flat and polyhedral with four to eight sides, and lengths ranging from 0.6 to 3.0 µm. They consisted of nanocrystals 41 nm wide, growing in the same direction. X-ray diffraction showed the crystals to be mineral phase aragonite, which was confirmed by Raman spectroscopy. Fourier transform infrared spectroscopy identified a band at 1,786.95 cm−1 attributed to carboxylate (carbonyl) groups of the proteins present in the organic matrix as well as bands characteristic of calcium carbonate. X-ray fluorescence showed the nacre to contain 98% calcium carbonate, as well as minor elements (Si, Na, S and Sr) and trace elements (Mg, P, Cu, Al, Fe, Cl, K and Zn).


2006 ◽  
Vol 11-12 ◽  
pp. 677-680 ◽  
Author(s):  
Gunawan Hadiko ◽  
Yong Sheng Han ◽  
Masayoshi Fuji ◽  
Minoru Takahashi

Hollow calcium carbonate (CaCO3) particles were synthesized by bubbling CO2 in the solution of calcium chloride (CaCl2) with the presence of ammonia at room temperature. Hollow calcium carbonate is a potential component to be used as pharmaceuticals, agrochemicals, and catalysis. This paper investigated the effect of additive on the hollow structure. In this study was used vanadate ion as additive agent. Physical characteristics of precipitate were evaluated using scanning electron microscopy (SEM) and X-ray diffraction (XRD).


2013 ◽  
Vol 310 ◽  
pp. 80-84 ◽  
Author(s):  
Bei Ping Liu ◽  
Jian Chen ◽  
Fang Bo Liu ◽  
Shi Biao Zhou ◽  
Yuan Dao Chen ◽  
...  

Calcium carbonate whiskers were successfully prepared in the MgC12-Ca(OH)2-CO2 system by a intermittent bubbling method and characterized by X-ray diffraction and scanning electron microscopy. The results demonstrated that aragonite style calcium carbonate whiskers with well morphology, large aspect ratio and smooth surface can be obtained by controlling technical conditions such as reaction temperature, concentration of Ca(OH)2 and amount of additives and under the conditions of CO2 flow velocity of 3.4ml/min/gCa(OH)2, flow of CO2 to air ratio of 1:4, stirring speed of 240 r/min.


2016 ◽  
Vol 680 ◽  
pp. 301-305 ◽  
Author(s):  
Ai Qing Jia ◽  
Wei Jun Zhang ◽  
Xing Yu Cheng ◽  
Zhuo Feng Liu

The CaO-B2O3-SiO2 glass ceramics system with four different boron contents (14 wt. %, 16.4 wt. %, 18.6 wt. %, 21 wt. %) were prepared under 900oC. The properties and microstructures are characterized by Differential Scanning Calorimeter (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The effects of boron contents on the composition of crystalline phases and the properties of CaO-B2O3-SiO2 glass ceramics system were studied. The results show that when the molar ratio of CaO/SiO2 is 1.06, as the content of B2O3 increases, the major crystalline phases experiences the transformation from CaSiO3 to CaB2O4 and the content of α-SiO2 crystalline phase decreases, and the dielectric constant increases firstly but it decreases after the content of B2O3 reaches to 18.6 wt. %, while the dielectric loss tgδ of decreases gradually with the addition of boron content. When the content of B2O3 is 16.4 wt. %, the CaO-B2O3-SiO2 glass ceramics with a bulk density of 2.47 g/cm3 exhibits good dielectric properties (1 MHz): εr=6.03, tgδ=3.49×10-3.


2021 ◽  
Vol 2 (1) ◽  
pp. 17-22

This research was conducted to determine the effect of CaCO3 levels on the formation of superconducting phase BPSCCO - 2212 by calculating the level of purity of the phases formed and looking at the microstructure. The variation of CaCO3 was 0.95, 1.00, 1.05 and 1.10 mole using the wet mixing method. The samples were calcined at 800 ° C for 10 hours, and sintered at 820 ° C for 20 hours. Synthesized samples were characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD’s chacterization results show that the level of purity of the formed phases increases with increasing Ca levels with maximum point at BPSCCO-2212/1.10 mole. The highest volume fraction was 79,06% in the BPSCCO-2212/1.10 sample. While the lowest volume fraction was 72.10% in the BPSCCO-2212/0.95 sample. Meanwhile, the highest degree of orientation was 20.59% at BPSCCO-2212/0.95. The lowest degree of orientation was 8.46% at BPSCCO-2212/1.10. SEM’s chacterization results show of all samples have been oriented altought not perfect yet and have relatively little space between slabs (voids).


2020 ◽  
Vol 1 (2) ◽  
pp. 53-57
Author(s):  
M Muntamijayati ◽  
◽  
Suprihatin Suprihatin ◽  
Yanti Yanti ◽  
Simon Sembiring ◽  
...  

The superconducting material BPSCCO-2212 with doping Pb = 0,2 has been synthesized by the wet mixing method. Calculation is caried out at 800 °C for 10 hours. While sintering is done at 825 °C, 830 °C, 835 °C and 840 °C for 20 hours. The synthesis result were characterized by XRD X-Ray Diffraction) and SEM (Scanning Electron Microscopy). The XRD spectrum analysis results that have been processed using celref, show that in general the samples produced have formed the BPSCCO-2212 phase (indicated the presence of Bi-2212 peaks) and have been oriented (indicated the existence of peaks with h = k = 0, l even number). For the calculation result obtanced the highest volume fraction value at 830 °C sintering temperature with a value FV = 66,97 % and the highest degree of orientation at 825 °C with a value of P = 76,54 %. The results of the SEM photo recorder generally show that the crystals formed are oriented.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


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