scholarly journals Use of Calcium Carbonate for Improving Solid Content of KOCC Wet Web

2013 ◽  
Vol 45 (6) ◽  
pp. 1-9 ◽  
Author(s):  
In-Young Hwang ◽  
Sung-Gil Ji ◽  
Yung-Bum Seo
Keyword(s):  
Calcium Carbonate ◽  
Solid Content

Study of Coating Binder Migration and Affected Parameters

2013 ◽  
Vol 790 ◽  
pp. 45-48 ◽  
Author(s):  
Zhao Hui Zhen ◽  
Zheng Shun Wang
Keyword(s):  
Calcium Carbonate ◽  
Cross Section ◽  
Coating Layer ◽  
Solid Content ◽  
Pigment Content ◽  
Drying Temperature ◽  
Coating Surface ◽  
Pigment Type ◽  
Binder Concentration ◽  
Coating Color

Because of the coating binder migration in cross-section of coating layer, the binder concentration will be different in z-direction of coating layer, which affect some properties of coated paper. The Paper studied the effects of pigment type, coating color solid content and dying temperature on binder migration and affected factors. The z-direction distribution of the coating binder which was tagged with Br in coating layer and its concentration in coating surface were examined quantitatively by using SEM-EDXA and ESCA analysis. The mechanism of binder migration was also proposed. The results indicated that the degree of binder migration is directly proportional to the drying temperature, that the increase of the ratio of calcium carbonate in the pigment content, coating surface binder concentration increased. The result also indicated that the degree of binder migration was increased with reduced the coating solid content.

Preparing Phenolic Resin / Calcium Carbonate Nanocomposites by Polymerization In Situ

2011 ◽  
Vol 281 ◽  
pp. 267-269
Author(s):  
Zhen Jia ◽  
Yi Xing Liu ◽  
Guo Liang Li
Keyword(s):  
Calcium Carbonate ◽  
Phenolic Resin ◽  
Solid Content ◽  
Preparation Process ◽  
Metathesis Reaction ◽  
Alkaline Catalyst ◽  
Good Research ◽  
Water Dilution

The objective of this paper is to use polycondensation in situ to prepare phenolic resin / calcium carbonate nanocomposites in alkaline catalyst. This paper explored the optimization time of produce in situ calcium carbonate making use of metathesis reaction in the system of phenolic resin condensation, and analyzed the effects of the added time on water dilution and solid content of phenolic resin / calcium carbonate nanocomposites. We obtained the optimum preparation process, which provided a good research base for studying further their performances.

Effects of Mg and Hydrogel Solid Content on the Crystallization of Calcium Carbonate in Biomimetic Counter-diffusion Systems

2014 ◽  
Vol 14 (9) ◽  
pp. 4790-4802 ◽  
Author(s):  
Fitriana Nindiyasari ◽  
Erika Griesshaber ◽  
Lurdes Fernández-Díaz ◽  
José Manuel Astilleros ◽  
Nuria Sánchez-Pastor ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Solid Content ◽  
Diffusion Systems ◽  
Counter Diffusion

scholarly journals Energy saving in papermaking by application of hybrid calcium carbonate

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5011-5023
Author(s):  
Min Woo Lee ◽  
Sun Young Jung ◽  
Yung Bum Seo
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Energy Savings ◽  
Solid Content ◽  
Pressing Pressure ◽  
Ionic Polymers ◽  
Paper Properties ◽  
Paper Drying ◽  
Ghg Reduction ◽  
Wet Pressing

Hybrid calcium carbonate (HCC) is prepared by pre-flocculating calcium oxide and ground calcium carbonate (GCC) with ionic polymers, and by injecting carbon dioxide to the pre-flocculated flocs until termination of the reaction at neutral pH. When used in papermaking, HCC gave higher bulk, higher stiffness, and higher tensile strength than GCC did. Furthermore, when higher wet pressing pressure was applied to the paper containing HCC, higher solid content was achieved with still better stiffness, smoothness, and tensile strength in comparison with the paper containing GCC. Actually, very high bulk of the HCC containing paper was compromisingly reduced to obtain high solid content by applying higher wet pressing pressure. Higher solid content achieved by combination of HCC technology and higher wet pressing pressure resulted in paper drying energy savings of more than 10%, while a high quality of all the essential printing paper properties was maintained. Drying energy savings may contribute to greenhouse gas (GHG) reduction and lowering of the paper production cost.

A TEM study of the microstructure of avian eggshells

1992 ◽  
Vol 50 (2) ◽  
pp. 1102-1103
Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Growth Mechanisms ◽  
Shell Surface ◽  
Thin Sections ◽  
Polycrystalline Metals ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.

Scaling risk assessment in a closed circuit recycled board mill by speciation methods

TAPPI Journal ◽  
2012 ◽  
Vol 11 (5) ◽  
pp. 53-61 ◽  
Author(s):  
PATRICK HUBER ◽  
SYLVIE NIVELON ◽  
PATRICE NORTIER
Keyword(s):  
Calcium Carbonate ◽  
Volatile Fatty Acids ◽  
Inorganic Carbon ◽  
Stability Index ◽  
Closed Circuit ◽  
Critical Problem ◽  
Local Scaling ◽  
Water Analyses ◽  
Closed Water ◽  
Speciation Calculation

Calcium carbonate scaling often is a critical problem for recycled board mills that have closed water circuits. The objective of this study was to determine local scaling risks throughout the production process. To predict scaling potential, we calculated several saturation indexes, based on speciation determined from detailed water analyses. Calculated scaling trends are in accordance with observed dissolution and precipitation of calcium carbonate in the process, when considering local aeration phenomena. The importance of volatile fatty acids (resulting from anaerobic bacterial activity) in calco-carbonic equilibriums is discussed, and taken into account in the speciation calculation. We also demonstrate the need to measure inorganic carbon instead of alkalinity in such conditions. This makes typical scaling indexes, such as the Ryznar Stability Index, irrelevant to predict scaling risk in closed circuit conditions; thus, it is necessary to use general speciation methods, as described in this paper.

A method for measuring the in-plane compressive strength and the compression behavior of coating layers

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Calcium Carbonate ◽  
Coating Layer ◽  
Test Methods ◽  
Coating Films ◽  
Precipitated Calcium Carbonate ◽  
Coating Color ◽  
Mineral Coatings ◽  
Styrene Butadiene

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.

The solubility of calcium carbonate  in green liquor handling systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 595-602
Author(s):  
ALISHA GIGLIO ◽  
VLADIMIROS G. PAPANGELAKIS ◽  
HONGHI TRAN
Keyword(s):  
Calcium Carbonate ◽  
Systematic Study ◽  
Kraft Pulp ◽  
Thermodynamic Simulation ◽  
Solubility Data ◽  
Pulp Mills ◽  
Persistent Problem ◽  
Green Liquor ◽  
Kraft Pulp Mills ◽  
Salt Systems

The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.

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