• Korean journal of food and cookery science
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• v.19 no.2
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• pp.216-222
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• 2003

The effects of hydrolysis times and calcium source additions (calcium lactate, calcium carbonate), on the qualify characteristics of soy ice cream prepared with soy protein isolate(SPI), were studied. Increasing the hydrolysis time decreased the viscosity and overrun of soy ice creams, but increased the melt-down property. The addition of calcium lactate increased the viscosity of the soy ice cream mix, but no changes were observed from the calcium carbonate addition. The overrun of calcium lactate samples was higher than on addition of calcium carbonate. The addition of calcium lactate and calcium carbonate resulted in decreased melt-down properties, although these effects were more evident in the calcium lactate samples. However, calcium carbonate addition resulted in higher scores in the overall quality of the soy ice creams. In conclusion, better soy ice cream could be prepared by treating the SPI with Flavorzyme for 50 min, along with calcium fortification in the form of calcium carbonate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.30-37
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• 2015

Needs for high ash loading in printing paper increase as green house gas (GHG) emission regulation becomes more stricter and pressure of lowering paper production cost increases. To meet the needs, a new type of filler was developed. The mixture of ground calcium carbonate (GCC) and calcium oxide was pre-floccuated with polyelectrolyte and further treated with carbon dioxide to form new calcium carbonate between GCCs. The final products were called as hybrid calcium carbonate (HCC), and its properties were compared to the GCC and the pre-flocculated GCC. Results showed increase in tensile, smoothness, opacity, and bulk for HCC.

• Elastomers and Composites
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• v.40 no.1
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• pp.12-21
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• 2005

In this work, magnesium carbonate and calcium hydroxide as metallic crosslinking agent were added to chlorosulfonated polyethylene rubber (CSM) emulsion to enhance the mechanical properties of emulsion film such as tensile strength, elongation at break, and tear strength and crosslinking density, thermal features, and surface energy were also investigated. Crosslinking density of the CSM emulsion film with increasing the amount of magnesium carbonate and calcium hydroxide increased, leading to the enhancement of water resistance. It was shown that compared with calcium hydroxide, magnesium carbonate had a little higher crosslinking density and $T_g$ value. The surface energy and mechanical characteristics of the CSM emulsion film, however, showed somewhat different behaviors. The highest surface energy, tensile strength, and tear strength were observed when 0.75% for magnesium carbonate and 1.0% for calcium hydroxide were added respectively. Therefore, it can be concluded that as metallic crosslinking agent to improve water resistance and mechanical properties of the CSM emulsion, magnesium carbonate is more preferable to calcium hydroxide.

• International Journal of Advanced Culture Technology
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• v.10 no.1
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• pp.284-293
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• 2022

After extracting the calcium component from the KR slag and the converter slag using ammonium chloride solution, the extract was reacted with carbon dioxide to synthesize precipitated calcium carbonate (PCC). In order to understand the effect of ultrasonic waves on calcium extraction from slags and calcium carbonate synthesis, the efficiency of calcium carbonate synthesis according to the with or without of ultrasonic waves was analyzed. The synthetic efficiency of PCC was investigated according to various experimental conditions, and the synthesized calcium carbonate was analyzed using XRD and SEM. In both slags, the amount of PCC decreased as the reaction temperature increased. The pH at the end of the experiment capable of synthesizing the maximum PCC in the carbonation reaction was 7 (irradiated with ultrasound) and 8 (irradiated without ultrasound), respectively. Because the pH of the extraction filtrate is different when irradiated with or without ultrasound, the pH was adjusted to 9 by injecting an additive (10 M NaOH) before the carbonation experiment, and then the experiment was performed. When calcium was extracted from KR slag, the crystal phase appeared as calcite regardless of the pH at the end of the experiment. However, when calcium was extracted from the converter slag and the pH was set to 7 at the end of the experiment, the crystal phase of PCC appeared as a mixture of calcite and vaterite.

• Journal of Powder Materials
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• v.16 no.3
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• pp.167-172
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• 2009

This study has been carried out to investigate the non-isothermal behaviors and kinetic parameter of calcium carbonate by different thermal analysis methods. At the heating rate of $10^{\circ}C$/min, the onset calcination temperature, the peak and final temperatures of calcium carbonate were $612^{\circ}C$, $748^{\circ}C$, and $890^{\circ}C$ respectively. As the heating rate of the calcium carbonate increased from $5^{\circ}C$/min to $20^{\circ}C$/min, the peak temperature increased from $719^{\circ}C$ to $782^{\circ}C$. The activation energies of the calcium carbonate calculated by the methods of Kissinger and Freeman-Carroll were 40.15 kcal/mol and 43.47 kcal/mol, respectively.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.443-455
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• 2017

This article provides an exclusive overview of the synthesized aragonite precipitated calcium carbonate and its applications in various fields. The last decade has seen a steady increase in the number of publications describing the synthesis, characterization and applications of calcium carbonate morphologies. Mainly, two kinds of processes have been developed for the synthesis of aragonite precipitated calcium carbonate under controlled temperature, concentrations and aging, and the final product is single-phase needle-like aragonite precipitated calcium carbonate formed. This review is mainly focused on the history of developed methods for synthesizing aragonite PCC, crystal growth mechanisms and carbonation kinetics. Carbonation is an economic, simple and ecofriendly process. Aragonite PCC is a new kind of functional filler in the paper and plastic industries, nowadays; aragonite PCC synthesis is the most exciting and important industrial application due to numerous attractive properties. This paper describes the aragonite PCC synthetic approaches and discusses some properties and applications.

• The Journal of Engineering Research
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• v.5 no.1
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• pp.73-87
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• 2004

The synthesis and crystallization of amorphous calcium carbonate($CaCO_3$.$nH_2 O$) obtained from gas-liquid reaction between aqueous solution of calcium hydroxide and carbon dioxide at 15~$50^{\circ}C$ are investigated by electrical conductometry, XRD and TEM. The results are as follows: The initial reaction products prior to the formation of precipitated calcium carbonate is amorphous calcium carbonate. The electrical conductivity values in the slurry are decreased during the formation of amorphous calcium carbonate which covers particle surface of calcium hydroxide and retard the dissolution of calcium hydroxide into the solution. that amorphous calcium carbonate is unstable in the aqueous solution and crystallizes finally to calcite by the through-solution reaction. While amorphous calcium carbonate crystallizes into chain-like calcite, the conductivity values are recovered rapidly and the apparent viscosity of slurry containing higher concentration of calcium hydroxide increase. At below pH 9.5, chain-like calcite separates into individual particles to form precipitated calcium carbonate. The formation and synthetic temperature range of amorphous calcium carbonate is most suitable a primary decreasing step(a-step) at $15^{\circ}C$ in the electrical conductometry.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.263-273
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• 1998

For histologic observation of the regenerated bone following guided tissue regeneration (GTR) using ePTFE membranes with calcium carbonate implant and autogenous bone graft, biopsies were collected from 2 patients during 5-year-postoperative surgical reentry. In both combined cases with guided tissue regeneration in conjunction with calcium carbonate implant and autogenous bone graft, significant bone fill and gain in probing attachment level was observed. In histologic examination, specimen in GTR case with calcium carbonate grafting was composed of a dense bone containing vascular channel with lamellar structure and viable bone cells in lacunae, however considerable calcium carbonate particles remained unresorbed and isolated from regenerated bone by the dense cellular and fibrous connective tissue. No formative cells could be seen in contact with remained calcium carbonate particles. In GTR case with autogenous bone grafting, specimen show was composed of a dense lamellar bone containing vascular channel, which showed normal alveolar bone architectures. The present observation indicate that guided tissue regeneration in conjunction with grafting, especially autogenous bone graft, has highly osteogenic potential, however resorbable calcium carbonate granules were not completely resorbed at 5 year postimplantation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.2
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• pp.166-170
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• 2000

Amorphous calcium carbonate was prepared by wet chemical method and performed the control of their shape using crystalline calcium carbonate that prepared from oyster shell by the $CO_2$ gas blowing method. As a result, amorphous calcium carbonate was obtained by the dissolution process of crystalline calcium carbonate in the dil-HC1 solution, mixing of sodium carbonate solution, precipitation and filtering with high speed. And using the amorphous calcium carbonate of mud type, crystalline calcium carbonates with cubic, needle, spindle, spherical and plate shape were obtained in the temperature rang of 2~$85^{\circ}C$ and reaction time range of 5~60 minute.

• Journal of Nutrition and Health
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• v.27 no.5
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• pp.473-482
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• 1994

This study was to compare the bioavailability of calcium from anchovy and tofu to those of calcium from calcium carbonate(CaCO3)as the control diet and non-fat dry milk(NFDM). Rats weighing 50-60g were placed on experimental diets and deionized water at free access for 4 weeks. Diets contained 0.2% calcium from calcium-carbonate, NFDM, anchovy, tofu or 0.5% calcium as obtained were as follows : 1) No significant differences in the apparent absorption of calcium(62.5%-71.0%) were observed in the rats fed four different calcium sources at the level of 0.2% while 0.5% calcium diet group apparently absorbed calcium less efficiently(52.2%). 2) Bone length of tibia and femur was not significantly different among the groups, though 0.5% calcium of control group showed slightly longer length. 3) Tibia fat-free dry weights of 0.2% calcium of NFDM and anchovy diet groups were not significantly different from that of 0.5% calcium of control group. For femurs NFDM, anchovy and tofu groups were similar in their fat-free dry weight to that of 0.5% calcium group. 4) For calcium contents tibia contents tibia from anchovy treated group showed higher value than calcium-carbonate and tofu groups and the value was not significantly different from that of 0.5% calcium group. In femur NFDM, tofu and calcium-carbonate groups were not significantly different in their calcium content but 0.5% calcium group had higher level of calcium than 0.2% calcium groups. 5) The normalized values(NV) show that there was no significant differences in NV among 0.2% CaCO3 anchovy and tofu groups, while NV of NFDM group was significantly lower than that of calcium-carbonate group. NV of 0.5% calcium group was a little more than 50% of those in 0.2% calcium groups. Though the values obtained for the calcium bioavailability were somewhat variable among experimental products, it was demonstrated that anchovy and tofu are as good as NFDM for the dietary calcium provider when calcium intake is at marginal level.