Preparation of Composite Ground Calcium Carbonate in Ca(OH)2–H2O–CO2 System and Characterization

2011 ◽  
Vol 287-290 ◽  
pp. 548-552
Author(s):  
Chao Huo ◽  
Jia Yuan Shen ◽  
Qing Hua Xia
Keyword(s):  
Calcium Carbonate ◽  
Rough Surface ◽  
Weight Ratio ◽  
Polymer Materials ◽  
Technological Parameters ◽  
Technical Parameters ◽  
Composite Ground ◽  
Higher Temperature ◽  
Ground Calcium Carbonate ◽  
Key Parameter

Ground calcium carbonate (GCC) is usually of smooth/flat surface and pointed edges angles which have disadvantageous effects on the mechanical properties of composite polymer materials filled with the powder. Nanometer calcium carbonate reactants would deposit, nucleate and grow on surface of ground calcium carbonate with micron grain size by adjusting suitable technical parameters in Ca(OH)2–H2O–CO2 system. Compared with the uncoated powder, composite ground calcium carbonate (CGCC) is of rough surface, blunt edges, larger specific surface area, larger in whiteness. In this paper, we reported the successful preparation of CGCC particles, and found GCC/Ca(OH)2 weight ratio was the key parameter. Some technological parameters were mainly analyzed for the coating process. Furthermore, We also prepared nanosized calcium carbonate coating GCC at higher temperature (40 °C) using additives. Filling tests showed that a rough surface of the CGCC enhanced contact opportunities and improved the interface between polymer and CGCC blended with polypropylene (PP).

Investigation of Composition and Technological Parameters of Highly Porous Gypsum Products Obtaining

2020 ◽  
Vol 299 ◽  
pp. 130-136 ◽  
Author(s):  
Lilia V. Ilina ◽  
Lubov V. Zavadskaya ◽  
Anastasia I. Ilina
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Specific Surface ◽  
Porous Structure ◽  
Glass Fibers ◽  
Technological Parameters ◽  
Aluminum Sulphate ◽  
Product Creation ◽  
Highly Porous ◽  
Ground Calcium Carbonate

A highly porous structure of a gypsum product creation is possible due to the porisation of gypsum mass, using new types of complex gas-forming components. At the same time, it is necessary to determine the technological conditions for the optimal formation of porous gypsum products structure and methods for increasing their strength. The article proposed to use dispersed calcium carbonate and aluminum sulphate, which interaction is the reaction with the release of СО2 for the porisation of the gypsum cast mixture. Micro-reinforcing additives, such as polymeric, basalt and glass fibers were introduced into gypsum composition together with building gypsum and finely ground calcium carbonate to improve the physico-mechanical properties of gas-gypsum. The best results were shown by the gas-gypsum, which included fiberglass. Glass fiber was pre-ground to a specific surface of 190-240 m2 / kg, in order to improve further the physico-mechanical properties of gas-gypsum.

scholarly journals New Method for Determining the Machine-Hand Welding Times Using Ultrasonic Welding Machines with Rotary Sonotrode

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 330
Author(s):  
Dubravko Rogale ◽  
Snježana Firšt Rogale ◽  
Željko Knezić ◽  
Siniša Fajt
Keyword(s):  
Ultrasonic Welding ◽  
Polymer Materials ◽  
New Method ◽  
Technological Parameters ◽  
New Model ◽  
Technical Parameters ◽  
Technical Textiles ◽  
Mathematical Expressions ◽  
Systematic Development ◽  
Relationship Of

The paper presents a new method for determining the machine-hand welding times of synthetic polymer materials using ultrasonic welding machines with rotary sonotrode. The method is based on the claims and observations of W. Möller intended for the clothing industry in the 1990s, according to which there is a spontaneous drop in sewing speed when strongly curved seams are joined, which is due to the possibility of human reactions. The method for determining machine-hand sewing times of curved seams was well accepted in garment production processes. It is used to standardize production time. Using ultrasonic welding machines with rotary sonotrode, the problem of determining the time of ultrasonic joining of curved seams on clothing or technical textiles remained unsolved. That is why is completely new and original model was created, which combines eight technical parameters of ultrasonic welds, eight technological parameters of the production process and seven ergonomic parameters depending on the psychophysical conditions of the workers. The systematic development of the mathematical relationship of all 23 parameters mentioned and the corresponding mathematical expressions for determining and calculating these parameters are presented. These results were also verified by experimental measurements, which show a favourable correlation between the calculated and measured machine hand times. The relationships between the recommended welding speeds, the critical radii of curvature and the number of reactions required according to Möller and the new model are also presented. An analysis of the success in the application of Möller’s and the new model was also performed.

scholarly journals Optimization of tablet formulation containing ginger dry extract

2020 ◽  
Vol 33 (2) ◽  
pp. 90-93
Author(s):  
Walid A.A. Malek ◽  
Olena Anatoliivna Ruban ◽  
Olga V. Kutova ◽  
Nataliia A. Herbina
Keyword(s):  
Tablet Formulation ◽  
Regression Equations ◽  
Diabetes Treatment ◽  
Optimal Composition ◽  
European Pharmacopoeia ◽  
Technological Parameters ◽  
Mathematical Methods ◽  
Dry Extract ◽  
Technical Parameters ◽  
Effective Drugs

AbstractIntroduction. Diabetes mellitus is one of the world’s most common diseases, therefore the development and introduction of new effective drugs for diabetes treatment into clinical practice is an important task for the health systems of many countries of the world.Aim. The aim of our work was to determine and substantiate the quantitative ratio of excipients for the development of the optimal composition of directly compressible ginger dry extract tablets.Materials and methods. To choose the optimal composition of tablets containing ginger dry extract, the effect of various quantitative ratios of the excipients Kollidon K30 and Neusilin UFL 2 on tablet mass pharmaceutical technical parameters, determined by established methods, was studied. For processing the experimental data, mathematical methods were used: design of experiment, regression analysis and a technique based on the theory of vector optimization.Results. The interrelation between factors that were studied and technological parameters of tablet mass and compressed tablets were analyzed using regression equations.Conclusions. The studies conducted allowed to chose the optimal composition of ginger dry extract tablets: ginger dry extract – 60%, Galen IQ 721 – 34.5%, Kollidon K30 – 3.5%, Neusilin UFL 2 – 1%, calcium stearate – 1%. The chosen tablet formulation is characterized by pharmaceutical technical parameters meeting the requirements of the European Pharmacopoeia and the State Pharmacopoeia of Ukraine.

scholarly journals Nitrogen-phosphate Fertilizers Based on Activation of Phosphorite Powder with Partially Ammoniated Mix of Phosphoric and Sulphuric Acids

2020 ◽  
pp. 1-10
Author(s):  
A. A. Rasulov ◽  
Sh. S. Namazov ◽  
B. E. Sultonov
Keyword(s):  
Citric Acid ◽  
Gross Domestic Product ◽  
Optimal Condition ◽  
Ammonium Sulphate ◽  
Weight Ratio ◽  
High Strength ◽  
Technological Parameters ◽  
Phosphate Fertilizers ◽  
First Time ◽  
Phosphoric Acids

In this article obtaining complex nitrogen-phosphate fertilizers based on activation of phosphorite powder with partially ammoniated mix of phosphoric and sulphuric acids have been studied. In order to reduce the foaming of the process, for the first time a partially ammoniated mix of acids was used. The optimal technological parameters for activation phosphorite powder with partially neutralized mixes of sulphuric and phosphoric acids are the followings: the mix of sulphuric and phosphoric acids with a ratio of SО3:Р2О5 = 1.2; рН of acids – 2.5; weight ratio of ammonium sulphate-phosphate slurry towards phosphorite powder is 100 : 20; temperature is 60°С; duration is 30 min.  The composition nitrogen-phosphate fertilizers obtained in optimal condition contains (wt., %): N – 11.55; Р2О5total -24.61; Р2О5acceptable by citric acid -21.66; Р2О5 acceptable by EDTA -20.24; Р2О5water-soluble  -13.02; CaOtotal -13.59; СаОacceptable by citric acid -11.43. In that condition, granulated products of nitrogen-phosphate can be produced with high strength. The advantage of offered promising technology concludes in reduction two times expenditure of the most expensive ammonia in comparison with ammonium sulphate production and an increase in gross domestic product.

scholarly journals Hybrid Precipitated Calcium Carbonate Containing Wood Flour for Paper Applications – A Comparative Handsheet Study

2019 ◽  
pp. 1-13
Author(s):  
Klaus Dölle ◽  
Kilian F. Baumgartner ◽  
Neil F. Goodman ◽  
Alexander Klitsiotisoris
Keyword(s):  
Calcium Carbonate ◽  
Filler Content ◽  
Wood Flour ◽  
Filler Material ◽  
Carbonate Mineral ◽  
Precipitated Calcium Carbonate ◽  
Hybrid Filler ◽  
Different Types ◽  
Flour Blends ◽  
Ground Calcium Carbonate

The main objective of this paper handsheet study is to investigate if a hybrid filler material containing wood flour and precipitated calcium carbonate can replace and/or supplement commercially available ground calcium carbonate and precipitated calcium carbonate mineral filler material for papermaking. The handsheet study contains 25 different furnish mixtures. Four different types of wood flour were used to manufacture the hybrid filler material, including two wood flour blends with a strengthening agent. All handsheet were manufactured with an 80% harwood and 20% softwood mix. The filler content varied between 10, 15 and 20%. The study showed that the hybrid filler material achieved a retention of up to 92.68% as well as a higher caliper of up to 208 μm compared to commercial ground and precipitated calcium carbonate of 120.4 μm and 145.6 μm respectively. Tensile and tear strength did not show an improvement. Elongation and tensile energy absorption did improve of up to 30% with the strength additive containing hybrid filler material. Opacity was improved of up to 10% with the hybrid filler material. Brightness and color values were lower due to the natural brow color of the wood flower material.

Effects of Rotation Speeds and Media Density on Ground Calcium Carbonate during Ultrafine Grinding Process in Planetary Mill

2014 ◽  
Vol 997 ◽  
pp. 542-545
Author(s):  
Yan Ru Chen ◽  
Yi Chen Lu ◽  
Xiao Min Lian ◽  
Chao Yang Li ◽  
Shui Lin Zheng
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Rotational Speed ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Grinding ◽  
Ultrafine Grinding ◽  
Effects Of Rotation ◽  
Ground Calcium Carbonate

Superfine ground calcium carbonate (GCC) produced by carbonate minerals is a widely used inorganic powder material. In order to get a finer GCC powder with narrow distribution span, the effect of rotational speed and media density on ground GCC were studied by dry grinding GCC in a planetary ball mill under different rotational speed and various media density. The grinding limit-particle size and distribution of grinding calcium carbonate were measured by centrifugal sedimentation granulometer. The structure of GCC was measured by X-ray diffraction. The result shows that low rotational speed and high-density media is conducive to get a product with smaller particle size and narrow size distribution; crystal plane (012) and (122) are more stable than (018) and (116).

Chemical Property of Ground Calcium Carbonate as Carbon Dioxide Absorbent

2010 ◽  
Vol 654-656 ◽  
pp. 2923-2926 ◽  
Author(s):  
Seiji Yokoyama ◽  
Nik Hisyamudin Muhd Nor ◽  
Shunsuke Hirano
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Calcium Carbonate ◽  
Physicochemical Properties ◽  
Specific Heat ◽  
Chemical Property ◽  
Emission Rate ◽  
Dissociation Reaction ◽  
Dissociation Pressure ◽  
Ground Calcium Carbonate

Commercial sedimentation CaCO3 was ground by a vibration rod mill to investigate the physicochemical properties of mechanically activated CaCO3.When the CaCO3of the calcite structure was ground, the intensities of the crystal facesof calcite was decreased by distortions and so on, and the aragonite appeared as the grinding proceeded. The formed aragonite was transformed to the calcite when the sample was heated at 773K for3.6 ks. The dissociation pressure of CO2 of the ground CaCO3was larger than that of the non-ground CaCO3.The enthalpy; entropy and specific heat of change of the dissociation reaction were obtained. At high temperature, the emission rate of the ground CaCO3 was slightly larger than that of the non-ground CaCO3. At room temerature, the CaCO3 adsorbs CO2, and it desorbs the adsorbed CO2. The amount of adsorbed CO2 on the ground CaCO3 was larger than that of the non-ground CaCO3.

Chemical Activation of Dicalcium Silicate and its Use for Cement Production

2019 ◽  
Vol 1151 ◽  
pp. 17-21
Author(s):  
Theodor Staněk ◽  
Martin Boháč ◽  
Petr Sulovský
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Ordinary Portland Cement ◽  
Chemical Activation ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Technological Parameters ◽  
Short Term ◽  
Cement Production ◽  
Belite Cement

In this work, it was found out that dicalcium silicate doped with SO3 shows higher hydraulic activity compared to pure dicalcium silicate. This finding was used to prepare and optimize high-belite cement from SO3 doped clinkers. The belite cement exhibited the same technological parameters, including short-term strengths, as ordinary Portland cement with a high content of tricalcium silicate. The clinker for belite cement is environmentally and economically advantageous. It is possible to burn the clinker at a temperature of 100 °C lower than conventional clinker and with lower consumption of calcium carbonate. In particular, methods of optical and electron microscopy were used for the research.

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