scholarly journals REPLACEMENT OF Ti02 PIGMENT BY CaC03 FROM CEFALONIA IN EMULSION PAINTS

2007 ◽  
Vol 40 (2) ◽  
pp. 759
Author(s):  
K. Kalafati ◽  
G. E. Christidis
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Great Part ◽  
Raw Material ◽  
Carbonate Content ◽  
White Pigment ◽  
High Calcium ◽  
Water Based ◽  
Tio2 Pigment ◽  
Optical And Mechanical Properties

The purpose of this work is to show that calcium carbonate from the chalky limestone deposits of Minies in Kefalonia, exploited by IONIAN KALK S.A., is a suitable raw material for paint industry and especially in emulsion (water based) paints. The deposit is characterized by a high calcium carbonate content (>99 %), high whiteness and low yellowness, by negligible content of heavy metals and low contents of MgO (<0.15 %), Si02 (<0.05 %) andFe203 (<0.01 %). This research was based on determination of the optical and mechanical properties of the emulsion white water based paints, which included calcium carbonate from the Kefalonia limestone deposits. The calcium carbonate replaced Ti02 pigment in various proportions. It is concluded that this product can be utilized not only as inert filler and extender but may have more functional application acting simultaneously as pigment. Replacement of TiO2 pigment by calcium carbonate may reach 50% without deteriorating the optical and mechanical properties significantly. Hence calcium carbonate from this deposit offers excellent optical properties to paints, reduces sufficiently their production cost and replaces a great part of the proportion of titanium dioxide, which is currently used as white pigment.

scholarly journals Effects of In-Situ Filler Loading vs. Conventional Filler and the Use of Retention-Related Additives on Properties of Paper

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5066
Author(s):  
Maria Emiliana Fortună ◽  
Andrei Lobiuc ◽  
Lucian-Mihai Cosovanu ◽  
Maria Harja
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Filler Loading ◽  
Carbonate Content ◽  
Sem Images ◽  
Paper Properties ◽  
Calcium Carbonate Content ◽  
Optical And Mechanical Properties ◽  
Filler Retention

In the present paper, aspects concerning the obtained and characterization of additive systems used for maximizing filler retention, and the effects on paper properties, were investigated. The effects of retention additives over properties of paper, containing fibers from in-situ loading (IS-CCP), were analyzed against the effects of additives over properties of paper containing fibers from conventional loading, obtained by the addition of calcium carbonate in precipitated form (CCP). The physico-mechanical properties were analyzed by various analyses and investigations: calcium carbonate content, X-ray diffraction, scanning electron microscopy (SEM) images, optical and mechanical properties, in order to develop the best systems of retention additives for obtaining higher retention loads for making paper with high content of nano-filler material. The obtained results reveal that at the same level of calcium carbonate content, all paper samples with in-situ loading had higher the optical and mechanical properties than the paper obtained by conventional loading in all cases the additives studied. For all studied properties, nanoparticles had a positively influence over paper properties.

Studies in the absorption and excretion of certain minerals by poultry. III. The influence of different levels of dietary calcium upon the retention of calcium, phosphorus, carbonate and chloride

1946 ◽  
Vol 36 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Cyril Tyler
Keyword(s):  
Calcium Carbonate ◽  
Dietary Calcium ◽  
Egg Laying ◽  
Carbonate Content ◽  
Phosphorus Excretion ◽  
Calcium Carbonate Content ◽  
High Calcium ◽  
Calcium Phosphorus ◽  
Different Levels

1. The daily retention of calcium, carbonate, phosphorus and chloride was studied using four birds and changing the calcium carbonate content of the ration every 5 days for 15 days.2. It was shown that high calcium diets result in a much lower retention of calcium and thin-shelled eggs are produced.3. Retention of calcium was higher in the laying than in the non-laying bird when calcium carbonate was fed.4. High calcium diets depressed the retention of phosphorus, and in one case the retention was negative, even when no eggs were laid. Laying birds gave negative values for retention because of the heavy phosphorus excretion associated with egg laying.5. High calcium diets also depressed the retention of chloride, and on occasion led to negative retention values.

Innovative Preparation Calcium Hydroxyapatite from Duck Eggshell via Pyrolysis

2016 ◽  
Vol 851 ◽  
pp. 8-13
Author(s):  
Nuchnapa Tangboriboon ◽  
Jularpar Suttiprapar
Keyword(s):  
Calcium Carbonate ◽  
Calcium Phosphate ◽  
High Purity ◽  
Average Particle Size ◽  
Calcium Hydroxyapatite ◽  
Environmental Conservation ◽  
Raw Material ◽  
Carbonate Content ◽  
Average Particle ◽  
Ceramic Yield

Calcium hydroxyapatite made from duck eggshell react to phosphoric acid with the Ca/P mole ratio 1.67 and calcined at 800º, 900º, and 1000°C for each temperature 2 hr. Duck eggshell is a source of calcium carbonate having high purity content more than 98.101 %w/w and small amount of other metal oxides. Duck eggshell is a bio-material similar to other calcium sources i.e. coral, animal bone, and seashell. There are many advantages of using duck eggshell as a raw material such as abundant, low price, high purity of calcium carbonate content, easy to calcium phosphate formation, biocompatibility, bioactive, non-toxic for human, and the high percentage of ceramic yield 69.73%w/w. In addition, one of the most important advantages is to reduce the amount of duck eggshell waste from household and food industries as environmental conservation. The optimum condition to obtain high purity hydroxyapatite is sintering calcium phosphate at 1000°C for 2 hr. The average particle size, specific surface are, pore diameter, and true density of sample sintered at 1000°C for 2 hr are 39.92 µm, 2.12 m2/g, 98.96 Å, 3.02 g/cm3, respectively, in soft fine white powder. Furthermore, the results obtained by XRF, SEM, and XRD confirmed of sample fired at 1000°C for 2 hr to be calcium hydroxyapatite (HA, Ca10(PO4)6(OH)2) of Ca/P mole ratio 1.67 and small amount of calcium phosphate (β-TCP, Ca3PO4) of Ca/P mole ratio 1.5. Therefore, the duck eggshell is a potentially bio-ceramic material to prepare calcium hydroxyapatite applied for biomedical, bio-dental, and many industries i.e. pharmaceutical, toothpaste, cosmetic, and nutrient food etc.

A source of error in the estimation of the organic matter content of samples containing calcium carbonate

1972 ◽  
Vol 79 (3) ◽  
pp. 541-542 ◽  
Author(s):  
F. D. DeB. Hovell ◽  
E. R. Ørskov
Keyword(s):  
Organic Matter ◽  
Calcium Carbonate ◽  
Volatile Fatty Acids ◽  
Organic Matter Content ◽  
Matter Content ◽  
Carbonate Content ◽  
Apparent Digestibility ◽  
High Calcium ◽  
The Difference

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)Organic matter (O.M.) = dry matter (D.M.)–ash.If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.

Preparation and Properties of Styrene Butadiene Styrene/Nano Calcium Carbonate Thermoplastics Elastomer Composite Foams: Morphology and Mechanical Properties

2017 ◽  
Vol 36 (5) ◽  
pp. 251-268 ◽  
Author(s):  
Maryam Vahidi ◽  
Hamed Azizi
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Carbonate Content ◽  
Cell Nucleation ◽  
Nanocomposite Foams ◽  
Composite Foams ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Morphology And Mechanical Properties ◽  
Butadiene Styrene

In this study, nanocomposite foams based on styrene-butadiene-styrene (SBS) copolymer and nanosized calcium carbonate (CaCO3) were prepared using chemical blowing agent (modified Azodicarbonamide) by compression molding at (230°C) temperature and (30MPa) pressure. The effect of nano CaCO3 concentration on cell nucleation rate, foam density, morphology and mechanical properties were studied for all samples. It was found that foam morphology and strength affected by nanofiller addition and its concentration. The results showed that SBS nanocomposite foam with 5 phr of CaCO3 nanoparticles have more cell density and smaller size cells compared with another samples. mechanical properties in compressive mode for foams were improved by increasing nano calcium carbonate content.

scholarly journals Effect of Calcium Carbonate on the Mechanical Properties and Microstructure of Red Clay

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Lijie Chen ◽  
Xuejun Chen ◽  
Xin Yang ◽  
Pengyan Bi ◽  
Xiang Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Carbonate Content ◽  
Shear Tests ◽  
Red Clay ◽  
Precipitated Calcium Carbonate ◽  
Sem Images ◽  
Clay Particles ◽  
Calcium Carbonate Content ◽  
Analysis System

The influence of precipitated calcium carbonate on the strength and microstructure of red clay was studied. Precipitated calcium carbonate was added to red clay at ratios of 0%, 5%, 10%, 15%, and 20%. Shear tests were carried out on the samples to observe the effect of calcium carbonate on the mechanical properties of red clay. The results showed that, with increasing calcium carbonate content, the strength of red clay first decreased and then increased. The maximum strength was obtained for the sample with 20% calcium carbonate. Scanning electron microscopy (SEM) was used to observe the changes in microstructure caused by addition of calcium carbonate. The pores and cracks analysis system (PCAS) was used to quantitatively characterize the microstructure changes detected in SEM images. The addition of calcium carbonate decreased the pore area and increased the total number of pores of red clay. The incorporation of calcium carbonate caused the red clay particles to agglomerate. The higher the calcium carbonate content, the stronger the agglomeration of red clay particles in the soil samples.

scholarly journals Effects of high concentrations of calcium salts in the substrate and its pH on the growth of selected rhododendron cultivars

2011 ◽  
Vol 80 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Piotr Giel ◽  
Krystyna Bojarczuk
Keyword(s):  
Calcium Carbonate ◽  
Calcium Content ◽  
Calcium Sulphate ◽  
Significant Rise ◽  
Soil Conditions ◽  
Carbonate Content ◽  
Calcium Salts ◽  
High Calcium ◽  
High Concentrations ◽  
Substrate Ph

For proper growth and development, rhododendrons need acidic soils, whereas calcium carbonate (CaCO<sub>3</sub>) in the substrate markedly limits their growth. In this study, we analysed the reactions of rhododendrons to high concentrations of calcium salts and pH in the substrate. We used 4-month-old seedlings of <em>Rhododendron</em> 'Cunningham's White' and 1.5-year-old seedlings and rooted cuttings of <em>R.</em> 'Cunningham's White' and <em>R.</em> 'Catawbiense Grandiflorum'. Their reactions depended mostly on calcium salt type added to the substrate (sulphate or carbonate). An increase in concentrations of phenolic compounds was detected mostly in roots of the plants grown in a substrate with a high calcium carbonate content. Addition of calcium salts to the substrate caused a significant rise in total nonstructural carbohydrates in leaves and roots of the studied plants. As compared to the control, an increase in substrate pH in the variant with calcium carbonate limited the activity of acid phosphatase, while lowering of substrate pH in the variant with calcium sulphate, significantly increased its activity. Along with the rise in substrate pH, a remarkable increase was observed in the activity of nonspecific dehydrogenase (DHA) in the substrate with CaCO<sub>3</sub>, as compared to the control. Unfavourable soil conditions (high calcium content and alkaline pH) caused a decrease in assimilation of minerals by the studied plants (mostly phosphorus and manganese). Our results show that the major factor limiting rhododendron growth is an increase in substrate pH, rather than an increase in the concentration of calcium ions.

scholarly journals Estimating the Absolute Salinity of China Offshore Seawater Using Nutrients and Inorganic Carbon Data

2020 ◽  
Author(s):  
Fengying Ji ◽  
Xuejun Xiong ◽  
Rich Pawlowicz
Keyword(s):  
Calcium Carbonate ◽  
Inorganic Carbon ◽  
Carbonate Content ◽  
Observation Data ◽  
Magnitude Distribution ◽  
Salinity Anomaly ◽  
High Calcium ◽  
Terrestrial Input ◽  
The Absolute ◽  
Evaluation Project

Abstract. In June 2009, the Intergovernmental Oceanographic Commission of UNESCO released the international thermodynamic equation of seawater – 2010 (TEOS-10 for short) (IOC et al, 2010) to define, describe and calculate the thermodynamic properties of seawater. Compared to Equation of Ocean State-80 (EOS-80 for short), the most obvious change of TEOS-10 is taking Absolute Salinity as salinity argument, replacing the Practical Salinity used in ocean society for 30 years. Due to lack of observation data, Absolute Salinity algorithm the applicability in the offshore and semi-closed sea is not very clear to date. Based on the Marine Integrated Investigation and Evaluation Project of China Offshore, other relevant data together with Pa08 model, we obtain the magnitude, distribution characteristics and formation mechanism of Absolute Salinity in China offshore. As the main composition anomaly relative to SSW, calcium carbonate, originating from terrestrial input of high calcium carbonate content and re-dissolution of sediment of China offshore, raises the Absolute Salinity Anomaly δSA as high as 0.20 g kg-1 and increases the Practical Salinity about 0.025 at most comparing to the chlorinity-based salinity. Moreover, both of them show obvious seasonal variation. Finally, relevant suggestions are proposed for the accurate measurement and expression of Absolute Salinity of the China offshore.

Analysis of the Causes of High Calcium Carbonate Content in Coal-Fired Power Plant Desulfurization Gypsum

2013 ◽  
Vol 781-784 ◽  
pp. 2582-2585
Author(s):  
Xue Ying Zhang ◽  
Xiao Xiang Zhou ◽  
Xue Feng Dong
Keyword(s):  
Calcium Carbonate ◽  
Power Plant ◽  
Power Plants ◽  
Carbonate Content ◽  
Calcium Carbonate Content ◽  
High Calcium ◽  
Powder Fineness ◽  
Lime Powder ◽  
Lime Stone

In this paper, the problem of high calcium carbonate content of desulfurization gypsum using limestone - gypsum wet desulphurization technology in coal-fired power plants questions, recommendations in running process from the control of absorption tower pH, lime stone powder, lime powder fineness activity to solve the above problems.

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