Calcium Carbonate Particle Size Research Articles

Controllable Synthesis of Nano-Micro Calcium Carbonate Mediated by Additive Engineering

Nano-micro calcium carbonate has a small particle size, uniform distribution, and good dispersion performance, offering great research value and development prospects. It has been widely used as a filler material for rubber, paper, ink, pigments, and coatings. Developing an efficient and controllable approach to preparing nano-micro calcium carbonate with adjustable morphology and controllable size has significant economic and environmental benefits. This study reports the controllable synthesis of nano-micro calcium carbonate meditated by additive engineering. The effects of various additives including inorganic acids, organic acids, alcohol, and surfactants on the particle size and morphology of the prepared materials were investigated. SEM, FT-IR and other characterization methods were used to analyze the prepared nano-micro calcium carbonate particle size, dispersion, and uniformity. The results showed that the particle size of calcium carbonate was 4~7 μm with a cubic structure. The particle size of calcium carbonate prepared by adding surfactant additives is in the range of 1~4 μm, and the crystal shape of calcium carbonate changes from calcite to vaterite after adding sodium dodecyl benzene sulfonate. With the aid of additives, the calcium carbonate particles dispersed more evenly. The mechanism of the controllable synthesis of nano-micro calcium carbonate mediated by additive engineering is elucidated and discussed. SDBS was found to be the best additive for preparing nano-micro calcium carbonate, and the synthesis conditions were explored and optimized.

Residual effects of pipeline construction on agricultural soils of the Canadian prairie

AbstractThe return to equivalent capability was evaluated on a >1000 km oil and gas pipeline corridor on the western Canadian prairies. Resource constraints limited this first phase of sampling to soils more likely damaged by disturbance. Three pipelines were selected to span a 55‐year period of construction. Data were collected from four transects established within each of six randomly chosen quarter sections (each 65 hectares) that included reference sites. Laboratory analysis provided data for organic carbon, pH, calcium carbonate equivalent, sodicity, salinity, and particle size distribution. Field procedures were used to obtain data for topsoil thickness, bulk density, aggregate size distribution, and carbonate distribution. The Canadian Land Suitability Rating System was employed to evaluate and compare the land capability (LSRS rating) of three pipelines to that of adjacent reference capability. Pipeline‐reference differences were detected in the topsoil for soil organic carbon (83% of reference), calcium carbonate equivalent (62% higher), and pH (0.4 units higher), and in the subsoil for bulk density (2% higher) and electrical conductivity (a fivefold increase). Carbonates were observed more frequently on the pipelines than on references. Soil organic carbon increased and electrical conductivity decreased with time since construction. The mode of land capability was class 4 on the corridor and class 3 on references. Residual effects remained. Neither soil conservation and reclamation practices, nor natural recovery had yet achieved equivalent capability for the target soil group, representing 17% of the extent of the corridor.

Influence on the magnetic field on the scale formation in a microfluidic channel under a low Reynolds number flow

This study presents an external magnetic array to rapidly investigate the calcium carbonate formation in a microfluidic channel. The system comprises a copper coil capillary serving as the heat exchanger, a high-precision thermostatic water tank, a magnetic drive pump, and an external magnetic array. Various factors were considered during the experiment, including different concentrations (3 mM and 10 mM) of the test solution, magnetic treatment efficiency (magnet length 4.0 cm and 14.0 cm, treatment time 24 h and 72 h), and temperatures ranging from 25 ℃ to 50 ℃. The concentration of calcium ions, electrical conductivity, and pH value were measured to monitor subtle changes during water treatment. Additionally, particle size distribution and morphology of calcium carbonate were analyzed using SEM and XRD under various magnetic treatments. The experimental results revealed that (1) applying a magnetic field to the solution in a microfluidic channel under low Reynolds number flow led to a decrease in the particle size of calcium carbonate, (2) aragonite did not form in the microfluidic channel, and (3) the physicochemical properties of the solution remained unaltered by the magnetic treatment. Consequently, the reduction in particle size can prevent blockage in microchannels, providing an alternative solution to mitigate scaling issues in micro-heat exchangers.

Effect of calcium carbonate particle size and content on the thermal properties of PVC foamed layer used for coated textiles.

The goal of this research is to see how the amount and particle size of calcium carbonate (CaCO3) used in the foamed layer in use for PVC-coated textiles affects the thermal properties of the material. Two different particle sizes were used at various concentrations. The impact of different CaCO3 loadings and particle sizes on the PVC foamed layer's thermal properties were examined. Thermogravimetry (TGA and DTG) and differential scanning calorimetry (DSC) measurements were utilized to investigate the thermal properties of the PVC foamed layer and the samples have been also characterized by FTIR spectroscopy. According to the findings, the thermal stability of the foamed layer was improved with the addition of calcium carbonate. Through the higher surface area between the filler and the PVC matrix, smaller particle sizes have produced the best results. The PVC foamed layer shows also changes in FTIR spectra after adding CaCO3, and the intensity of peaks increases with decreasing CaCO3 particle size.

The effect of calcium carbonate content and particle size on the mechanical and morphological properties of a PVC foamed layer used for coated textiles

Due to recent developments in composite formulations and coating technology, polyvinyl chloride (PVC)-coated textiles are becoming increasingly popular in the textile industry. The most critical properties of PVC-coated textiles are their mechanical characteristics and morphological properties because they control their cost well. This study focuses on the impact of filler diameter and content on the mechanical properties of the PVC foam layer used for coated textiles stuffed with calcium carbonate (CaCO3). The mechanical properties of the PVC foamed layer (breaking load, tearing strength and elongation at break) were studied. The applied contents were found to significantly influence the mechanical properties of the PVC foamed layer. The addition of CaCO3 fillers improved their mechanical properties. The results also showed that mechanical properties were enhanced using calcium carbonate with different particle sizes; the smallest particle size gave the highest mechanical resistance. The morphology of the different samples showed that the employment of calcium carbonate increases foam formation. A higher CaCO3 content can deteriorate the PVC foam layer structure. Using a small filler particle diameter decreased pore sizes and ameliorated the regularity in pore size distribution.

Properties of Self-Compacting Concrete Using Multi-Component Blend Binders for CO2 Reduction

This paper aims to reduce the quantity of cement used by up to 80% by utilizing industrial by-products. By reducing the amount of cement used, there is an effect of reducing CO2 emissions during cement manufacturing. To reduce the amount of cement used, ground granulated blast-furnace slag (GGBF), fly-ash (FA), and calcium carbonate (CC) were used as substitute materials for cement. CC is a by-product, discharged by collecting CO2 emitted from a coal-fired power plant and reacting with additives. The specific surface area and the average particle size of CC used are 12,239 cm2/g and 5.9 μm (D50), respectively. The viscosity of pastes that contained GGFF and FA decreased by up to 51 and 49% respectively compared to the use of only cement (OPC) paste. However, paste using with CC increased up to 23% in relation to plain. As a result of measuring slump flow, segregation resistance ability, and filling ability to evaluate construction performance, slump flow was reduced by up to 3% (G40F10C30) in relation to plain concrete. Segregation resistance ability of fresh concrete using, GGBF (15, 30, and 45%), FA (10, 20, and 30%), CC (10, 20, and 30%), the time it takes for the slump flow to reach 500 mm, time it takes to through the V-funnel showed a decreasing tendency as the usage of FA increased. However, CC increased with increasing mixing ratio. This trend is, the viscosity increase when CC was mixed in terms of rheology. Filling ability of fresh concrete using GGBF (15, 30, and 45%), FA (10, 20, and 30%) and CC (10, 20, and 30%), the criteria were met, and the average increase was 16% and the maximum was 20% in relation to plain concrete. In the case of compressive strength, the compressive strength at 1 day was found to be an average of 5 MPa when 80% of the cementitious was substituted. At 3 days, at least 8 MPa was measured. The compressive strength at 28 days showed a tendency to decrease as the mixing rate of CC increased, but was measured to be at least 34 MPa. The relationship between compressive strength and splitting tensile strength or elastic modulus at 28 days satisfies the standard range.

Effects of Amino Acids on the Composition and Particle Size of Calcium Carbonate Precipitated in Bile

Effects of Amino Acids on the Composition and Particle Size of Calcium Carbonate Precipitated in Bile

Preparation of Calcium Carbonate by Three-Stage Bubbling Carbonation in CaCl2-NH4Cl-NH3-H2O SYSTEM

To prepare calcium carbonate with reduced particle size and single vaterite phase based on the mineral carbonation technology of steel slag, preparation of calcium carbonate in system was studied by using two and three-stage bubbling carbonation under different reaction pH values and stirring conditions in the presence of ultrasound in this paper. The results show that the calcium carbonate has already gathered and the particles are small and clearly defined when the first aging pH value is 9.0. With the decrease of pH value, the particle size of calcium carbonate increases significantly with more than one peak in the particle size distribution curve, the particle surface tends to be smooth, and the calcite content increases gradually. However, the two-stage bubbling carbonation process can reduce the particle size significantly and is applicable to the system. Different stirring conditions have no significant influence on calcium content, pH value, or phase, which is mainly composed of vaterite and calcite in twostage carbonation, while the stirring in the aging stage will increase the particle size of calcium carbonate. Base on the results of the two-stage carbonization reaction, the three-stage bubbling carbonation is proposed and the calcium carbonate prepared is all single vaterite type, and its size and the agglomeration between the particles are also significantly reduced, and the stirring also has no significant influence. The formation mechanism of two and three stage bubbling carbonation reaction was also discussed.

"Effect of Operating Parameters and Particle Size of Calcium Carbonate on the Physical Properties of Latex Paint"

Dr. Engr. Sheraz Ahmed Qureshi* Author Affiliations General Manager Technical, PhD in Chemical Engineering, MSc Chemical Engineer, MS (Total Quality Management), MBA, Brighto Paints Private Limited Pakistan and UAE Received: September 13, 2021 | Published: September 24, 2021 Corresponding author: Dr. Engr. Sheraz Ahmed Qureshi, General Manager Technical, PhD in Chemical Engineering, MSc Chemical Engineer, MS (Total Quality Management), MBA, Brighto Paints Private Limited Pakistan and UAE DOI: 10.26717/BJSTR.2021.39.006236

A Novel Resorbable Composite Material Containing Poly(ester-co-urethane) and Precipitated Calcium Carbonate Spherulites for Bone Augmentation—Development and Preclinical Pilot Trials

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.

Non-isothermal decomposition kinetics of nano-scale CaCO3 as a function of particle size variation

We report the synthesis of nanocrystalline calcium carbonate with varying particle sizes by precipitation techniques from an aqueous solution of calcium nitrate and sodium carbonate at controlled pH. The particle size of the carbonate powder was precisely controlled by changing the precursor concentration. The synthesized carbonate powders were characterized by using scanning electron microscopy, X-ray diffraction technique, and transmission electron microscopy. The particle size, along with the crystallite size of as-synthesized carbonate powder, decreases with increasing precursor concentration. The non-isothermal decomposition kinetics of the carbonate powder was also evaluated by using near to the modified Arrhenius equation's exact solution. The experimental results were best fitted at n = 0.5, and the one-dimensional diffusion-controlled transport process mechanism (D1) and one-dimensional phase boundary movement mechanism (R1) was found to be very close fit of the corresponding evaluated g(α) value. The apparent activation energy of the nano calcium carbonate decomposition was found in the range of 120–175 kJ/mol, which is also inherently functioning with the average particle size. The apparent activation energy of decomposition of CaCO3 found to be decreased with decreasing average particle size of nanocrystalline calcium carbonate.

Experiment on microbial grouting reinforcement of tailings under the regulation of egg white

Microbial Induced Calcium Carbonate Precipitation (MICP) has some disadvantages, such as low crystallization conversion rate of calcium carbonate and insufficient strength properties of tailings. In this paper, a modified method combining soft template calcium carbonate mineralization technology with microbial grouting reinforcement technology was proposed. The tailings solidification was studied with the control of nine different concentrations of egg white (0%, 5%, 10%, 15%, 20%, 30%, 40%, 60% and 80%). After 14 days of grouting reinforcement experiment, the results are as follows. ① The shear strength of tailings was improved remarkably, and the best reinforcement effect was at 5% egg white. Compared with the control group, the effective cohesion of tailings increased by 437.61%. ② The fitting curve between the content of calcium carbonate in tailings and its cohesion shows that there is an exponential relationship between them. ③ The results of microscopic examination showed that the proportion of columbite-type calcium carbonate increased with the increase of egg white concentration. The corresponding egg white concentration of calcite-type calcium carbonate was 5%. At this time, the maximum particle size could reach 100 µm. ④ The infrared absorption characteristic curves of the interporous cements of tailings indicate that the changes of crystal form, crystal morphology and particle size of calcium carbonate may be due to the strong interaction between polar groups such as NH, CH and CO in the composition of egg white and calcium carbonate crystal. ⑤ The bonding, connecting and packaging of fibers in egg white will cause fundamental changes in the bonding mode of tailings. The test results showed that the combination of mineralization regulation of egg white and MICP technology can achieve complementary advantages, which is of great engineering significance for improving the stability and safety of tailings dam.

The preparation of calcium carbonate with different morphologies under the effect of alkanolamide 6502

The shape, size and polymorph of the crystals will affect their separation, drying and other properties. Surfactants may affect the crystallization process and crystalline products’ properties by changing the surface tension in the solution. In this paper, the effects of alkanolamide 6502 as additive on the morphology of calcium carbonate was studied under the conditions of different additive volumes, temperatures and stirring rates. The results showed that the presence of alkanolamide 6502 has a certain effect on the morphology and crystal form of calcium carbonate. The addition of alkanolamide 6502 during the crystallization process was conductive to form vaterite, and the particle size of calcium carbonate was more uniform. Meanwhile, alkanolamide 6502 can change the surface properties of the product from hydrophilic to hydrophobic, preventing the agglomeration. Moreover, vaterite is more likely to form in the presence of alkanolamide 6502, and it is explained from the perspective that adsorption of hydroxyl on the crystal surface changes the physical surface properties of the crystal and inhibits the transformation of polymorphs.

Improving precipitate calcium carbonate (PCC) particle size distribution for a continuous mineral carbonation system

Mineral carbonation is a process where carbon dioxide (CO2) is converted into solid carbonates. The product of mineral carbonation is obtained when CO2 is being contacted with alkaline earth metals, such as calcium and magnesium. In this research, the team focusing on producing precipitated calcium carbonate (PCC), as a solution to manage CO2 release which comes from high CO2 content natural gas field production. To make this process economically feasible, the team has researched obtaining valuable PCC quality which is marketable in various industries. The quality mainly measured in terms of particle size, where the particle size will determine the application of the PCC. This study investigates the effect of feed solution retention in reactor towards PCC particle size, using continuous mineral carbonation system. In this system, Milk of Lime, which is Calcium Hydroxide (Ca(OH)2) solution used as feed. To produce this solution, 7 g/L Calcium Oxide (CaO) is suspended in deionized water and stirred. This solution is injected in the range of 0.8 L/min to 1.2 L/min into pressurized CO2 in the range of 10 bar to 80 bar. The retention time is varied by using mechanically modified reactor inlet cap, where the feed inlet time is delayed by elongation of feed injector inside the reactor by 15 cm (NEWCAP). Particle size of the product was analyzed by using Malvern Mastersizer 3000. Experimental data show that by shortening the feed solution retention time inside the reactor, will produce smaller particle size. Using the unmodified reactor inlet, the obtained product particle size ranging (D50) from 15 micron to 25 micron. On the other hand, using NEWCAP reactor inlet the obtained particle size ranging (D50) from 8 micron to 20 micron.

Effect of dextran and enzymatically decomposed dextran on calcium carbonate precipitation

AbstractThe effect of dextran's molecular mass distribution (T40, T500, T2000, and enzymatically decomposed T2000) on the size and shape of calcium carbonate particles precipitated during carbonation, a step in the sugar manufacturing process, was investigated. Image analysis combined with size exclusion chromatography was used to distinguish harmful and harmless dextran sizes aiming at targeted mitigation of dextran‐related effects by dextranase. The data indicate that dextran with molecular masses above 10 kDa promotes agglomeration, indicated by an increase in particle projection area. This effect was especially found for broadly distributed intermediate but rather low molecular mass dextran (10–85 kDa). Based on particle shape data, the agglomeration of calcium carbonate crystals in the absence and in the presence of low molecular mass dextran (<85 kDa) appears to be oriented and similar to each other. In contrast, the data suggest that high molecular mass dextran (>85 kDa) promotes nonoriented agglomeration and an increase in surface roughness. Once the dextran was significantly decomposed by enzyme action (10 or 50 mg/kg juice) to smaller molecules in the size range below 10 kDa, no dextran‐related effects on particle size and shape were found anymore.Practical applicationsThe presence of dextran is known to cause several adverse effects during sugar manufacture. Among them, dextran can affect the size and shape distribution of calcium carbonate particles precipitated during carbonation as a part of the sugar beet raw juice purification. As a result, the purification as well as the filtration process can be affected. These dextran‐related effects are usually mitigated by enzymatic decomposition, a gradual reduction in molecular mass. For a targeted enzyme application, the decomposition products need to be identified and the corresponding effects due to varying molecular mass fractions on the precipitation of calcium carbonate need to be analyzed. Only then, a sufficient decomposition to harmless molecule sizes can be ensured. Thus, the data gathered give a clear guidance for dextranase treatment in sugar manufacture.

Effect of the addition of calcium carbonate on the barrier behavior of polyamide 11 used in offshore applications by electrochemical impedance analysis

In offshore oilfield exploration, flexible pipe technology has gained importance as a convenient and effective way to connect seafloor wellheads to sea level oil platforms. This structure has several layers each one presenting specific functions: polymeric layers – fluid barrier and metal layers – mechanical strength. Polyamide-11 (PA11) was one of the first polymers used for the internal insulation layers in flexible pipes used in offshore oilfield exploitation. The aim of this work is to evaluate the effect of calcium carbonate particle size (nanoparticles – NPCC and microparticles – PCC) on the barrier properties of PA11 matrix, the grade used in the pressure layer of flexible pipes, towards the diffusion of ions and molecules present in crude oil. This evaluation was based on acquisition of Electrochemical Impedance Spectroscopy data, which helps to interpret the metallic corrosion behavior. The results indicated that the PA11/NPCC system formed a better protective corrosion barrier over carbon steel due to its higher polarization resistance when compared to neat PA11 and PA11/PCC composite.

Exploring the Influence of Reaction Parameters on the Preparation of Calcium Carbonate by Spontaneous Precipitation

AbstractDifferent polymorph and morphology of CaCO3 powder are prepared by spontaneous precipitation method in the presence of sodium citrate and NaOH at ambient temperature. The influence of spontaneous precipitation reaction parameters such as aging time, pH value, the concentration of complexing agent sodium citrate on the crystal phase, particle size and morphology of the precipitated calcium carbonate is studied in this paper. The prepared samples are characterized by scanning electron microscopy (SEM) and X‐ray diffraction (XRD). The results show that the aging time, the pH of the solution and the concentration of sodium citrate turned out to be important for the morphologies and crystal phase of CaCO3. Increasing the aging time, the content of vaterite decreases slightly, whereas the opposite effect is observed for increasing pH. When pH value is 13, pure calcite irregular nanoparticles can be prepared. In the presence of sodium citrate, the content of vaterite increases as the increasing of sodium citrate. When the concentration of sodium citrate is increased to 0.1 m, uniform vaterite microsphere with 5 µm size can be obtained.

Ultrasonik Ses Dalgası Ortamında Polielektrolit Varlığında Kalsiyum Karbonat Sentezi, Karakterizasyonu ve Deneysel Tasarım

In this study, calcium carbonate (CaCO 3 ) was synthesized by means of ultrasonic irradiation process in the presence of the water-soluble polyelectrolyte Poly(Vinyl Sulfonic Acid) (PVS). Synthesized CaCO 3 crystals were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size and thermal analysis (TGA-DTA). The effects of the amplitude of sonicator, polymer concentration and the application time of ultrasound on the obtained CaCO 3 with respect to particle size of final product was investigated by applying the 2 k Factorial design. The experimental design was studied at two levels. All the selected process parameters were found to be very effective on the particle size of calcium carbonate obtained in the presence of PVS.

Effect of calcium carbonate particle size on formation and morphology of calcium hexaboride powder synthesized from condensed boric acid-poly(vinyl alcohol) product

Calcium hexaboride (CaB6) powder was synthesized by carbothermal reduction via the transient boron carbide (B4C) formation starting from a condensed boric acid (H3BO3)-poly(vinyl alcohol) (PVA) product. The effect of the size of calcium carbonate (CaCO3) particles on the formation behavior of CaB6 and the obtained particle morphology was investigated in this study. CaB6 powder was prepared using CaCO3 powders with microsize or nanosize particles. The CaB6 formation reaction was accelerated at lower temperature and shorter heat treatment time when using nanosize CaCO3 particles. The complete formation of CaB6 was achieved at 1400 °C for 3 h in an Ar flow. Furthermore, CaB6 powder with nanosize particles was obtained. The precursor powder obtained using nanosize CaCO3 particles transiently formed fine B4C and calcium borate particles, which are reactive species of CaB6, leading to the facile formation of fine CaB6 particles.

Morphology of calcium carbonate prepared via homogeneous synthesis

The morphology of calcium carbonate prepared via homogeneous synthesis from carbonate–chloride solutions was studied. The precipitates were investigated by scanning electron microscopy (SEM) and Xray diffraction. The effects of the ratio between the chloride and carbonate components of a solution on the morphology, crystal structure, and particle size of precipitated calcium carbonate were illustrated.