Calcium Carbonate Powder Research Articles

Physicochemical Characterization of Biofield Energy Treated Calcium Carbonate Powder

Calcium carbonate (CaCO3) is widely used in pharmaceutical industries and as a supplement in probiotics. The present study was designed to evaluate the effect of biofield energy treatment on the physicochemical properties of the CaCO3. The CaCO3 powder was divided into two parts and referred as control and treated. The control part was remained untreated, whereas treated part was subjected to Trivedi’s biofield treatment. The control and biofield treated samples were characterized using X-ray diffraction (XRD), particle size analyzer, surface area analyzer, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The XRD showed that the crystallite size of treated CaCO3 was increased up to 100% as compared to the control. In addition, the lattice strain was reduced in treated sample as compared to the control. The particle size analysis result showed that the average particle size was significantly changed after treatment that led to considerably enhance the specific surface area of treated CaCO3 powder by 95% as compared to the control. The FT-IR spectroscopic analysis of the treated calcium carbonate showed shifting of wavenumber attributed to symmetric stretching vibrations of carbonate ion to higher wavenumber as compared to the control. The TGA analysis showed reduction in weight loss and increase in char yield which may be due to the increase in thermal stability of the treated sample. Therefore, the biofield treatment had significantly altered the physicochemical properties of the calcium carbonate. Hence, it is assumed that treated calcium carbonate could be used as a potential supplement of probiotics for food applications.

Effect of adsorption of polyhexamethyleneguanidine derivatives on the formation rate, morphology, and phase composition of carbonate deposits

It was found that introduction of polyhexamethylguanidines modified with carboxy and phosphonic groups into a saturated solution of calcium carbonate affects the formation rate, morphology, and phase composition of the deposits being formed, with crystals in the deposit becoming coarser and rhombic structures appearing. These phenomena were manifested to a greater extent when zinc complexes of polyelectrolytes are present in solution. An analysis of the phase composition of the deposit demonstrated that the presence of polyelectrolytes and their zinc complexes in solution leads to an increase in the amount of the calcite phase. The reason why the phase composition and morphology of the deposits changes is that polyelectrolytes and their complexes are adsorbed on the surface of carbonate deposits. The adsorption of polyelectrolytes on a calcium carbonate powder is described by the Langmuir isotherm and the formation of their zinc complexes leads to an increase in the adsorption equilibrium constant by more than a factor of 2, which is due to the change in the hydrophilic-lipophilic balance of macromolecules in complexation.

Calcium carbonate as a possible dosimeter for high irradiation doses

The aim of this work is to analyze the interactions of 5MeV electron beam radiation and a 290MeV/u Carbon beam with calcium carbonate (powder) at 298K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9MGy, and with Carbon beam from 1.5kGy to 8kGy.High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR).An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation.

Calcium carbonate powder containing gentamicin for mixing with bone grafts.

Bone grafts are used for reconstructing bone defects caused by implant-associated complications, trauma, and tumors. Surgery with bone allografts is complex and time consuming; therefore, it is prone to a higher infection rate (2.0%-2.5%). In the case of site infection, systemically administered antibiotics cannot reach the infected bone graft. This study evaluated the use of resorbable bone graft substitute powder (HERAFILL; Heraeus Medical GmbH, Wehrheim, Germany) as a bone void-filling material as well as an antibiotic carrier for mixing with bone grafts. The antibiotic activity of the bone chips mixed with HERAFILL powder was measured by drug release tests and bacterial susceptibility with Bacillus subtilis, Staphylococcus epidermidis, and Staphylococcus aureus. HERAFILL powder was added to the bone chips (bone chips/HERAFILL; w/w = 1:1), mixed with a spatula, and vortexed for 1 minute. Gentamicin base release was evaluated in phosphate-buffered saline for up to 7 days using B subtilis bioassay. Antimicrobial efficacy was tested with S aureus and S epidermidis. The average amount of gentamicin base released from bone chips mixed with HERAFILL at 0 to 12 hours was 99.66 mg/mL. On day 7, the gentamicin base released 0.42 mg/mL. The elution released from bone chips mixed with HERAFILL promoted the formation of a zone of inhibition on S epidermidis and S aureus plates. This study confirmed the capacity of bone grafts to act as antibiotic carriers once mixed with HERAFILL powder. Bone chips mixed with HERAFILL showed efficacy against S aureus and S epidermidis.

Activation energies of high-volume fly ash ternary blends: Hydration and setting

Because ready-mixed concrete is placed under a wide variety of environmental conditions, the influence of temperature on the hydration reactions and the accompanying setting process is of critical importance. While contractors are generally quite comfortable with the temperature sensitivity of conventional ordinary Portland cement (OPC) concretes, more sustainable mixtures containing high volumes of fly ash (HVFA), for example, often present problems with delayed setting times and increased temperature sensitivity. Based on isothermal calorimetry and Vicat needle penetration measurements, this study demonstrates that the high temperature sensitivity of such HVFA mixtures can be effectively moderated by the replacement of a portion of the fly ash with a fine calcium carbonate powder. In addition to accelerating and amplifying hydration and reducing setting times at a given temperature, the presence of the fine CaCO3 powder also lowers the apparent activation energy for setting for temperatures below25°C. The reactivity of the CaCO3 in these mixtures is quantified using thermogravimetric analysis. Comparison of results for CaCO3 powders of nominal sizes of 1μm and 17μm, replacing 10% by volume of the cement in an OPC mixture, indicates that the former is highly superior in accelerating/amplifying hydration and reducing setting times.

The Research of Hydrolysis Test of Silicone Water Repellent for Protecting Reinforced Concrete

It is one of the measures of improving durability of concrete structure that apply silicone water repellent on concrete surface. The characteristic of silicone water repellent is to keep the respiratory function of concrete, not to change the original appearance of the concrete, have good hydrophobic performance and can resist to chloride ion penetration. This paper studies the hydrolysis of silicone water repellents solutions with different pH by measuring the electrical conductivity, pH value, and surface tension of the solution. The results show that silicone water repellent is hydrolyzing quickly very much. The hydrolysis time will extend with the increase of the concentration of silicone water repellent. By means of impregnating sand, rubble, cement pieces and calcium carbonate (CaCO3) powder with silicone water repellents, the water absorption at different temperature and humidity are studied and compared with the same material but not impregnated. The results indicate that the water absorption of impregnated material decreases and the silicone water repellent has hydrophobicity. The higher humidity can help hydrolysis and adhesion of silicone water repellent. The higher temperature may increase water absorption of base materials impregnated with low molecule weight silicone water repellent. Low molecule weight silicone water repellent liquid is residue on the calcium carbonate powder surface.

Influence of Composition and Isothermal Sintering on the Properties of Hydroxyapatite Bioceramic Bodies<sup></sup>

This work reports the influence of chemical composition and sintering schedule on the properties of sintered bodies of hydroxyapatite (HA) bioceramic. The method of preparing sintered bodies by solid state reaction and uniaxial pressing. The raw material used calcium carbonate (CaCO3) and ammonium dihydrogen phosphate (NH4H2PO4) powder as precursors. These powders were mixed at CaCO3: NH4H2PO4 mass ratio of 1:0.697, 1:0.692, 1:0.689, 1:0.685 and 1:0.68, respectively. The compositions in the temperatures range of 800-1300 °C for 3 hour. The sintered bodies were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Properties including phase, microstructures, porosity and bending strength of the samples. The results show that green bodies can be sintered at 1150 °C for 3 hours. This temperature found that crystals growth, highest of HA phase content in sintered bodies, good density and high efficiency strength properties.

EPR investigation of UV light effect on calcium carbonate powders with different grain sizes.

This study is based on investigation of calcium carbonate powders with different grain sizes exposed to UV light. Calcium carbonate is widely used in many branches of industry, e.g. as a filler for polymer materials; therefore, knowing its properties, among them also its reaction to UV light, is essential. Samples of powdered calcium carbonate with average grain sizes of 69 and 300 nm and 2.1, 6, 16, 25 µm were used in this investigation. Measurements were performed at room temperature using EPR X-band spectrometer, and they have shown the additional signals induced by the light from Hg lamp. The effect of annealing of the micro-grain samples was also studied. The spectra of four micro-grain samples after irradiation are similar, but there are differences between them and the other two powders, which could be related to the different sizes of their grains. Further studies based on these preliminary results may prove useful in research of photodegradation of CaCO3-filled materials, as well as helpful in increasing the accuracy of dating of archaeological and geological objects.

Mechanical, Thermal and Wear Characteristics of Polymer Composite Material Reinforced with Calcium Carbonate Powder

Mechanical, Thermal and Wear Characteristics of Polymer Composite Material Reinforced with Calcium Carbonate Powder

The charging efficiency and flow dynamics of micropowder during jet milling/electrostatic dispersion

Jet milling is a highly efficient method for preparing micro-sized powder in many areas of industry. However, aggregation of the micro-sized powder during processing often offsets the advantages of jet milling to a certain extent. In this work, we discuss a new method to prepare micro-sized powder through the combination of jet milling and electrostatic dispersion(J/E). This method helps to achieve the dual goal of producing fine powders and concurrently maintaining the dispersiveness of the powder product. Calcium carbonate (CaCO3) powders with two different mean particle sizes (10.93 and 25.43μm) were used as raw materials. The effects of the preparation parameters (the charging voltage and the air pressure) on the charging efficiency of the powder were investigated. We have also simulated the flow dynamics of particles in the J/E chamber using COMSOL Multiphysics software. The results indicate that the charge to mass ratio (q/m) of the powder increases with the increase of the charging voltage until it reaches saturation, and the saturation charge of the raw powder with a larger mean size is higher at an air pressure of 0.3MPa. When the charging voltage was −60kV, the q/m of the raw powder with a smaller size reached its maximum at 0.2MPa, whereas that of another type of the powder achieved its maximum at 0.3MPa. This suggests that the q/m is determined by the competition between the two conflicting factors, i.e. the refined particle size and the charging time, both influenced by the air pressure and the mean particle size of the raw powder at a given charging voltage. In addition, simulation of the flow dynamics reveals that the dispersion of the particles is enhanced during the transport in the J/E chamber, with increases in the jet velocity and the charging voltage. The effect of the charging voltage is more obvious.

Influence of Calcium Carbonate Powder on Water Requirement and Flowability of Self-Compacting Mortar Incorporating Bagasse Ash

Bagasse ash (BA) is a plentiful byproduct obtained from the process of electricity generation during sugar manufacturing. We investigated the influence of adding calcium carbonate powder (CCP) to self-compacting mortar (SCM) mixtures. Type 1 Portland cement was replaced with 0%, 20%, and 40% as-received or ground BA and CCP by weight. Mixtures were designed to yield a slump flow spread of 25.0 cm in diameter. The water requirement and V-funnel flow time of each SCM mixture were determined.

Statistical Model for Describing Macronutrient Impacts on Container Substrate pH Over Time

Although many factors that influence substrate pH have been quantified, the effect from fertilizers continues to be elusive. A multifactorial experiment was conducted to test macronutrient effects using a rarely used statistical method known as the central composite design. Five nutrient factors, including nitrogen (N) carrier ratio (NH4+ vs. NO3–) and concentrations of phosphorus (P) (as H2PO4–), potassium (K), combined calcium (Ca) and magnesium (Mg), and sulfur (S), were varied at five levels each encompassing the proportionate range of these nutrients in commercial greenhouse fertilizers. Although a typical factorial experiment would have resulted in 55 = 3125 treatments, the central composite design reduced the number to 30 fertilizer treatments. An experiment was conducted twice in which ‘Evolution White’ mealy-cup sage (Salvia farinacea Benth.) was grown in 14-cm-diameter pots (1.29 L) in a 3 peat:1 perlite (v/v) substrate amended with non-residual powdered calcium carbonate to raise the substrate pH to ≈5.6 to 5.8. Harvests occurred after 3 and 6 weeks of growth. A statistical model described substrate pH over time with significant effects including four main effects of N carrier ratio, P, K, and combined Ca and Mg; three squared terms of N carrier ratio, P, and K; and seven interaction effects. The resulting model was used to calculate substrate pH levels between 25 and 45 days after planting, and it showed that N carrier had the greatest impact on substrate pH.

Evaluation of Mechanical Properties and Morphological Studies of Bagasse Fibre (Chemically Treated/Untreated)-CaCO3 Epoxy Hybrid Composites

In past few years natural fibre composites have become very important part of research as potential structural material. The present study deals with a new class of chemically treated/untreated natural fibre and calcium carbonate reinforced composites. In the present investigation composites of bagasse fibre (10 % w/w) and calcium carbonate powder of size ≤30 μm (2 and 4 % w/w) with epoxy resin have been examined. The lengths of bagasse fibre have been varied from 1 to 5 mm. The fibres were chemically treated with NaOH (5 % w/v). Morphological changes of the fibres were observed under the scanning electron microscope. Addition of calcium carbonate showed increased mechanical properties of the developed composites like, flexural strength, compression strength. The composites reinforced with chemically treated fibres show better mechanical properties as compared to the composites reinforced with untreated fibres.

Scalable and template-free production of mesoporous calcium carbonate and its potential to formaldehyde adsorbent

Here, we report a scalable and template-free production strategy in the synthesis of a mesoporous calcium carbonate, which undergoes self-assembled nanostructure formation through a temperature-induced aggregation and polymorphic transformation of the colloids. The specific surface area and pore size distribution of resulting mesoporous calcium carbonate are clearly different depending on the aging temperature. The specific surface area and average pore size for aging temperature of 293 K are 207.3 ± 9.8 m2/g and 8.8 ± 0.6 nm, respectively, and 65.1 ± 10.1 m2/g and 19.9 ± 2.6 nm at 473 K. Additionally, we apply the mesoporous calcium carbonate powder to formaldehyde vapor adsorbent. We measure the adsorbed amount of gaseous formaldehyde and find that the vaterite-rich powder has larger adsorption per unit area than the calcite-rich one.

Calcium phosphate based materials starting from calcium carbonate and orthophosphoric acid for the removal of lead(II) from an aqueous solution

Calcium phosphates starting from calcium carbonate and orthophosphoric acid as unconventional and low cost initial reactants were investigated in the removal from aqueous solution of lead(II) as model heavy metal. Sorbent in gel form, which was directly obtained from the reaction of calcium carbonate powder and orthophosphoric acid, and sorbent in powder form, which was obtained by filtration and drying of the gel at room temperature showed the highest reactivity for the removal of lead(II). The sorption capacity could reach up to 1226mg of lead(II) per gram of powder sorbent. On the other hand, the conventional drying overnight at 105°C decreased the reactivity of the sorbent in powder form. The intermediates of the reaction between calcium carbonate and orthophosphoric acid, including brushite (CaHPO4·2H2O), monetite (CaHPO4) and MCPM (Ca(H2PO4)2·H2O) were found to be more active than hydroxyapatite (Ca10(PO4)6(OH)2) which was the final stable product of the reaction between calcium carbonate and orthophosphoric acid. Lead hydroxyapatite (Pb10(PO4)6(OH)2) was the main crystalline phase formed from the contact of calcium phosphate based sorbents with lead(II) nitrate solution. It was only formed at the external surface or surface of open-pores of calcium phosphate particles, highlighted by SEM characterization. The results obtained open new prospects for the design of efficient orthophosphate-based sorbents for the removal of lead(II) and other heavy metals from liquid effluents.

Establishment of a prediction model for the cut size of turbo air classifiers

Cut size is one of the core indices for the classification performance of turbo air classifiers. It is directly affected by operation parameters, such as feeding speed, rotor cage rotary speed, and air inlet velocity. Under these considerations, this study presents a method for establishing a prediction model for the cut size of turbo air classifiers. The method is developed on the basis of a dimensionless equation to obtain an empirical formula for cut size. The calcium carbonate and talc powder classification experiments on a turbo air classifier are carried out to obtain training samples and testing samples. Then the prediction model is calculated by multiple-variable nonlinear regression based on training samples. The verification tests for both calcium carbonate and talc powder testing samples indicate that the predicted cut sizes are closer to the experimental results than the findings calculated according to the theoretical formula in other references. The influence of operation parameters on cut size is also determined using the prediction model. Cut size decreases with increasing rotor cage rotary speed and increases with increasing air inlet velocity. At a high feeding speed, the probability of particle aggregation increases with increasing solid concentration, thereby decreasing cut size. As indicated by the indices of the cut size prediction model, the air inlet velocity and rotor cage rotary speed distinctly influence cut size, whereas feeding speed exerts a negligible effect. The proposed modeling method can be used to establish prediction models for the cut sizes of the turbo air classifier, serving as foundation for regulating the operation parameters for classification.

Study on Radioactive Wastewater Treatment by Precipitation and Membrane Separation

The chemical precipitation method was combined with the membrane separation to treat the simulated radioactive wastewater containing strontium in the paper. The calcium carbonate powder was used to prepare the seed and the sodium carbonate was selected as the precipitant. Sr2+ and CO32- constantly crystallized on the seed surface in the granulation reactor. FeCl3 was dosed in the subsequent membrane separator. The average concentrations of strontium in the raw water and in the effluent were 5.046 mg/L and 0.028 mg/L, respectively. The DF increased gradually with the operation time, with an average value of 279. After the test, the formed precipitate was easy to separate from the liquid and was directly discharge after sedimentation for 24 h. The CF was 3170. The membrane specific flux decreased rapidly in the early stage and then declined slowly with the operation time.

Effect of Strength Enhancement of Soil Treated with Environment-Friendly Calcium Carbonate Powder

This study aims to investigate the effects of the strength improvement of soft ground (sand) by producing calcium carbonate powder through microbial reactions. To analyze the cementation effect of calcium carbonate produced through microbial reaction for different weight ratios, four different types of specimens (untreated, calcium carbonate, cement, and calcium carbonate + cement) with different weight ratios (2%, 4%, 6%, and 8%) were produced and cured for a period of 3 days, 7 days, 14 days, 21 days, and 28 days to test them. The uniaxial compression strength of specimens was measured, and the components in the specimen depending on the curing period were analyzed by means of XRD analysis. The result revealed that higher weight ratios and longer curing period contributed to increased strength of calcium carbonate, cement, and calcium carbonate + cement specimens. The calcium carbonate and the calcium carbonate + cement specimens in the same condition showed the tendency of decreased strength approximately 3 times and two times in comparison with the 8% cement specimens cured for 28 days, but the tendency of increased strength was approximately 4 times and 6 times in comparison with the untreated specimen.

Improvement in the Unconfined Compressive Strength of Sand Test Pieces Cemented with Calcium Phosphate Compound by Addition of Calcium Carbonate Powders

Improvement in the Unconfined Compressive Strength of Sand Test Pieces Cemented with Calcium Phosphate Compound by Addition of Calcium Carbonate Powders

A comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women

BackgroundCalcium is an essential mineral often taken as a daily, long-term nutritional supplement. Data suggests that once-daily dosing is important with regard to long-term compliance of both drugs and nutritional supplements.ObjectiveThis study was undertaken to compare the bioavailability of a single serving of two calcium supplements in healthy, premenopausal women.DesignA two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45. All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents. Blood measurements for total and ionized calcium and parathyroid hormone were performed and adverse events were monitored.ResultsTwenty-three women were evaluable with a mean age of 33.2±8.71. Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001). There were minimal side effects and no reported serious adverse events.ConclusionsThis study shows that a single serving of a calcium carbonate powder is more bioavailable than a single serving of calcium citrate tablets. This may be beneficial for long-term compliance.