• Korean Chemical Engineering Research
• /
• v.55 no.1
• /
• pp.1-6
• /
• 2017

More addition of calcium carbonate in printing paper allows savings of the wood fibers and the drying energy. Pre-flocculation of GCC (ground calcium carbonate) using functional polymers was known as the best available technology to make high loaded paper until now, and it allowed less reduction of the paper essential properties such as tensile strength and smoothness at higher GCC content. However, pre-flocculated GCC became unstable in size under the continued agitation in the mill. Therefore, pre-flocculation method was modified in such a way that the in-situ calcium carbonate was formed between the GCC particles of the pre-flocculated GCC, and the resultant became more stable in size, which we named as HCC (hybrid calcium carbonate). HCC turned out to make high tensile strength and smoothness as much as the pre-flocculated GCC and gave much better size stability against stirring. Furthermore, HCC gave high bulk that pre-flocculation could not make.

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

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.475-480
• /
• 2001

Mechanical properties of mortars and concretes blended with GCC(Ground Calcium Carbonate slurry) and silica fume were investigated. Results from this study showed that air contents of mortars were constant regardless of replacement of GCC and flow values of mortars were decreased with replacement of it. Especially, mortars and concretes replaced with 10% of GCC had a good trend with respect to compressive strength. In case of simultaneous use of GCC and silica fume, the workability and compressive strength of the concretes seem not to be any problems in mechanical properties. This study indicated that the most reasonable replacement of GCC was 10% and the addition as fine aggregate was more effective than that as binder.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.217-220
• /
• 2006

This paper describes a study undertaken to determine the effect of ground calcium carbonate(GCC) cement mortar with respect to sulfate attack. It were investigated visual appearance and expansion of cement mortars with GCC immersed in artificial solution of 5% sodium sulfate during 510days. According to increasing replacement of GCC, the expansion ratio was comparatively superior to GCC0 mortar specimen. The test results indicated that cement mortars with GCC was benefit the resistance of sulfate attack due to micro filler effect.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.560-564
• /
• 2001

Nowadays, according to the trend of a high performance of concrete structure, the research results have been announced for the purpose to make the high quality. With this respect, we began research to use the Ground Calcium slurry Carbonate (GCC) to a concrete admixtures which ground the limestone until about $1.5mutextrm{m}$. In this paper, we examined the quality of GCC to fine out the value in use as the concrete admixtures. And mechanical properties of concrete using cement blended with GCC, silica fume and mixed two were investigated. It was result from this study that air contents of concrete replaced with GCC were constant regardless of replacement ratio, but the more GCC it had the use of, the less slump was measured. Especially 10% GCC concrete had a good result of compressive strength. In case of mixture with GCC and silica fume, the workability and compressive strength don't seem to be any problems. In the scope of this study it was indicated that the most reasonable replacement with GCC was 10% of cement weight as concrete admixture.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.29 no.1
• /
• pp.7-12
• /
• 1997

This study was intended to investigate the proper shape and size of calcium carbonate for the improvement of paper properties and its end use performance. We loaded calcium carbonate of various shapes and size in the handsheet and measured their physical and optical properties. Results obtained from the study are summarized as follows : 1. Due to different particle shapes and sizes, precipitated calcium carbonate (PCC) contributed greater to bulk improvement than ground calcium carbonate (GCC). Scalenohedral form of PCC produced the bulkiest sheet, GCC made the sheet bulkier as average particle size increases. 2. Tensile strength increased as average particle size was increasing. GCC kept tensile strength more effectively than PCC. The effect of particle size on tensile strength was much more pronounced as filler addition level was increasing. 3. Over the average particle size of 6.99$\mu$m, GCC gave much higher burst strength and internal bond than PCC did. In the filler levels of 20% and 30%, GCC by using bigger size fillers showed 50~100% improvement in some cases than PCC at the same filler content. 4. Tear strength increased as average particle size was increasing. At the filler level of 30%, PCC decreased tear greatly. 5. Over the average particle size of 13.56$\mu$m, GCC kept bending stiffness greater than PCC. Due to its shape, Scalenohedral form of PCC showed higher stiffness than others at the same particle size. 6. Cubic and acicular form of PCC improved light scattering coefficient very effectively. Light scattering coefficient of GCC decreased as average particle size increased. 7. Both of particle shape and size of filler were important factor in developing optical properties and bending stiffness. Particle size was the only important factor in developing other strength properties

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.73-78
• /
• 2002

This study examines self-compacting of concrete using Ground Calcium Carbonate(GCC) gathering in limestone mine of Banyans district in order to make self-compacting concrete in the range of design strength 300kgf/cm$^2$ and the optimal mix proportion of self-compacting concrete that can use in field structure. The result shows that the optimal GCC replacement ratio is 45$\pm$5% in the normal strength of design strength 300kgf/cm$^2$ and that the volume ratio of the optimal fine aggregate used as the way satisfying both viscosity and compacting ability without separating materials is 46%. The optimal volume ratio of the coarse aggregate considering the economical aspect of concrete is 50%. It is desirable that the optimal mix proportion satisfying self-compacting for replacement of GCC is decided through mix design according to each replacement ratio.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.553-556
• /
• 2006

Generally, concrete is one of the most widely used construction materials, because of its good durability to cost ratio. However, when subjected to severe environments its durability can significantly decline due to various harmful conditions. In this article, we would like to investigate a chloride ion diffusion of cement matrix with inert filler, which ground calcium carbonate(GCC). For the experimental results of the chloride ion diffusion, as the addition of GCC makes decreasing the permeability by micro-filler effect, the matrix of 5-15% ratio of replacement are superior to the GCC0 mortar matrix with respect to durability of cement matrix in this scope.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.3
• /
• pp.35-42
• /
• 2011

In this study, ground calcium carbonate (GCC) was modified by Layer-by-Layer (LbL) multilayering with polyelectrolytes. Cationic polyacrylamide (C-PAM) and poly sodium 4-styrene sulfonate (PSS) were used as cationic and anionic polyelectrolytes to modify GCC. The characteristics of the modified GCC were examined in terms of zeta potential and particle size with the addition level of polyelectrolyte and layer number. The GCC could form an assembly of cationic and anionic polyelectrolytes through consecutive adsorption process. The zeta potential of the modified GCC moved toward the cationicity and reached the plateau with the increase of the addition level of C-PAM. With layering of anionic PSS, the GCC had the negative charge. The particle size was dependent on the zeta potential. It was also observed by optical microscope. As the PSS was in the presence of the outermost layer, the GCC showed the better dispersability. It indicated that the surface charge and particle size can be controlled by adjusting the addition level of polyelectrolyte and the layer number.

• Journal of Forest and Environmental Science
• /
• v.18 no.1
• /
• pp.97-105
• /
• 2001

The main objective of this study was to investigate effects of pigment mixed with different ratio on the double coated paper. Mineral pigments such as clay and ground calcium carbonate(GCC) as well as hollow sphere plastic pigment were used to evaluate the physical, optical properties and printabilities of double coated paper. The physical properties such as gloss and smoothness, and the printability(ink gloss) of double coated paper were measured to evaluate the effects of the bottom layer on improving the properties of top layer. The data indicated that the usage of hollow sphere plastic pigment for the bottom layer coating improved the surface properties of double coated paper, and that ink gloss was significantly influenced by the structure of bottom layer even when hollow sphere plastic pigment was used for the bottom layer coating.