Synthesis Of Precipitated Calcium Carbonate Research Articles

Effects of Organic Additives on Portlandite Microstructure during CaO Hydration

This study evaluates the effect of various organic additives on the microstructure of portlandite crystals during the hydration of CaO. Calcium hydroxide mixed with selected additives was prepared and characterised in terms of crystal size and habit, platelets abundance, and particle size distribution using various techniques such as XRD, SEM and Particle Size Analysis. The results suggest that the microstructure of portlandite is altered by the presence of carbohydrates and sulfonates, showing higher platelets abundance, smaller crystallite size, and higher specific surface area. The presence of hydroxyl-rich carbohydrates induces more marked effects compared to sulfonates. These results show that it is possible to tailor the properties of lime to specific applications in both, the conservation and the construction industry. Furthermore, the results show that it is possible to enable the development of materials specifically dedicated to other applications such as the synthesis of precipitated calcium carbonate and the design of CO2 sorbents, all of which will have the added value of reducing the global anthropogenic CO2 emissions.

Effects of carbohydrates and sulfonates during CaO hydration on portlandite microstructure

This study evaluates the effect of ten organic additives belonging to the classes of carbohydrates and sulfonates on the microstructure of portlandite crystals during CaO hydration. Calcium hydroxide modified with selected additives was prepared and characterised in terms of crystal size and habit, platelets abundance, crystallinity, specific surface area, particle size distribution, calcium concentration and organics in solution, using XRD, SEM, N2 absorption/BET, laser diffraction, ICP-OES and HPLC-MS. The results suggest that the microstructure of portlandite is altered by the presence of carbohydrates and sulfonates, mostly showing higher platelets abundance, smaller crystallite size, and higher specific surface area. The presence of hydroxyl-rich carbohydrates induced more marked effects compared to sulfonates. These results show that it is possible to tailor the properties of lime to specific applications. Consequently, this study can impact the conservation and the construction industry by enabling the development of novel binders for modern construction with optimal properties, and more broadly fields such as the synthesis of precipitated calcium carbonate and the design of CO2 sorbents, all of which will have the added value of reducing the global anthropogenic CO2 emissions.

Synthesis of precipitated calcium carbonate with the addition of aloe vera extract under different reaction temperatures

Synthesis of precipitated calcium carbonate with the addition of aloe vera extract under different reaction temperatures

Practical insights into the recycling of green mussel shells (Perna Viridis) for the production of precipitated calcium carbonate

The study presented a powder processing method involving calcination and subsequent carbonation in the synthesis of precipitated calcium carbonate (PCC) for recycling green mussel shells, which contain a high calcium carbonate content. The purity of portlandite [Ca(OH)2] as a result of calcination and subsequent moisture absorption during storage was verified using the XRD-Rietveld method. Further quantitative XRD Rietveld analysis of the PCC product confirmed the presence of vaterite (55.20 wt.%) and calcite (44.80 wt.%) minerals after carbonation process of the calcined powder product. The SEM examination of this product revealed particle aggregates of non-uniform polyhedral and cubical grains of varying small and large sizes. The FTIR analysis also confirmed that calcination and subsequent hydration of mussel shell powder yielded pure portlandite, whereas the carbonation yielded PCC polymorphism. As a result, this powder processing method is simple to scale and reduces the cost of PCC synthesis, which is critical for practical applications. The current study demonstrated that the powder processing method for recycling green mussel shells as starting materials in biomedical applications is technically feasible.

Simultaneous Biogas Upgrade and Production of Precipitated Calcium Carbonate

Biogas upgrading is a necessary step to remove impurities and increase a calorific value of biogas before it can be used as a proper energy source. The most significant impurity in raw biogas is typically carbon dioxide, composing up to 50% of biogas volume. Carbon dioxide capture is therefore an important part of the upgrading process which in turn raises the question of the availability of final carbon storage. This problem can be addressed by using calcium hydroxide solution or other lime-based solvents as scrubber in carbon dioxide capture via carbonation where precipitated calcium carbonate (PCC) is formed as a by-product. This paper reviews the viability of packed column, bubble column, and spray column for simultaneous biogas purification by CO2 capture and PCC synthesis, as well as examining various parameters that affect both carbon dioxide capture and the production of PCC. Among the three reviewed types of contactors, only packed column is deemed unsuitable for the simultaneous process. The optimal condition for both carbon dioxide scrubbing efficiency and PCC yield can be obtained by using a high liquid flow rate, low gas flow rate, and high solvent concentration. However, the desired characteristics of PCC should be considered in determining the operating parameters as the said characteristics such as crystal phase, morphology, and particle size are affected by several operating parameters, namely gas flow rate, solvent concentration, temperature, size of bubbles, and concentration of additives.

Calcium extraction and synthesis of precipitated calcium carbonate from Mg-rich dolomite

Abstract A green-reaction assisted synthesis using a natural occurring dolomite is reported for precipitated calcium carbonate production over aloe barbadensis miller extract template under ambient condition. Uniform, hierarchical aragonite precipitated calcium carbonate stacked from nanoparticles was synthesized. The tainted Mg influence on resultant PCC purity was averted via D-glucose extraction of dolomite constituent calcium and subsequent precipitation using CO2. The as-synthesized PCC was characterized using SEM, XRD, PSD, and FTIR spectroscopy. Under ambient conditions using carbonation route and 1 L/min CO2 flowrate, aragonite polymorph with hierarchical flower-like structure was produced. Energy is conserved as heat is not required for phase transformation. Minerals & Environment (RAMM) 2018.

Precipitation Rate Investigation on synthesis of precipitated calcium carbonate

Study on the formation of precipitated calcium carbonate from natural limestone Sukabumi with the influenced of various parameters such as precipitation rate, concentration of CaCl2 and amplitudes were investigated. We also investigated the result with the precipitated calcium carbonate from Merck (p.a) for comparison. The higher concentration of CaCl2 would give effect to the lower of the precipitation rate. It was observed that precipitation rate of calcium carbonate from limestone Sukabumi at concentration of 0.08 molar was 3.66 cm/minutes and showing the optimum condition, while the precipitation rate of calcium carbonate Merck at the concentration 0.08 molar was 3.53 cm/minutes. The characterization of precipitated calcium carbonate was done using X-ray fluorescence (XRF) and scanning electron microscope (SEM). The characterization using XRF showed that CaO content of precipitated calcium carbonate from natural limestone Sukabumi had high purity of 99.16%. The particle distribution using scanning electron microscope (SEM) showed that precipitated calcium carbonate from natural limestone Sukabumi revealed 1.79 µm – 11.46 µm, meanwhile the particle distribution of precipitated calcium carbonate Merck showed larger particles with the size of 3.22 µm – 10.68 µm.

Effect of Calcination on the Hydration Activity and Production ofPrecipitation Calcium Carbonate

Precipitated calcium carbonate (PCC) is known as purified and refined synthetic calcium carbonate. PCC is synthesized through calcination process to convert limestone to quicklime, hydration process to make slaked lime and carbonation process to produce precipitated calcium carbonate. PCC is largely classified into calcite (stable phase) and aragonite (metastable phase), and this polymorphism is due to the characteristics of limestone ores and the differences of calcination/hydration/carbonation process conditions. In this study, the effects of the calcination and hydration behavior on the synthesis of PCC will be discussed using limestone with different chemical composition.

Synthesis of precipitated calcium carbonate: a review

The current high global demand for high-quality paper, paint, adhesive/sealant, and plastic, filler industries cannot survive without unique and high-quality precipitated calcium carbonate (PCC). They are used as fillers, additives, and reinforcements. PCC is a key constituent of the modern paper and plastic industry. This article reports the effect of various organic and inorganic additives used in the synthesis of the different polymorph of calcium carbonate. The use of precipitated calcium carbonate fillers is the recommended choice in enhancing optical properties, durability, smoothness and ink adsorption in papermaking and improving the mechanical properties of plastic. PCC can best be synthesized using solid–liquid route or the gas–solid–liquid carbonation route, which consists of bubbling gaseous CO2 through a concentrated calcium hydroxide (Ca(OH)2) and/or calcium magnesium hydroxide (Ca·Mg(OH)2) slurry with suitable organic additives. The use of several organic and synthetic additives in conjunction with different reaction parameters for the synthesis of the various polymorph of precipitated calcium carbonate is reported. Depending on the desired end use, PCC polymorphs such as aragonite, vaterite and calcite are vital in the plastic and rubber industries.

Continuous synthesis of precipitated calcium carbonate using a tubular reactor with the aid of aloe vera (Aloe barbadensis Miller) extract as a green morphological modifier

Green templating agents for evolving new morphologies and shapes of precipitated calcium carbonate (PCC) with wide-ranging potential applications are desirable. In this study, aloe vera (Aloe barbadensis Miller) extract (0.5%–5%, v/v) was utilized as a green modifier for the synthesis of a PCC composite with a new crystalline structure. A continuous PCC synthesis was conducted using a tall and narrow tubular column reactor with a favorable height-to-diameter ratio (l/d = 150 cm/10 cm). The morphology, particle size, crystalline structure, and thermal characteristics of the synthesized PCC were studied by scanning electron microscopy, X-ray diffraction, particle size distribution, thermogravimetric analysis, differential thermal analysis, and Fourier transform infrared spectroscopy. Aloe vera extract concentrations above 0.5% (v/v) significantly influenced the particle size and morphology of the synthesized PCC but only marginally influenced the PCC yield. Under ambient temperature, and using aloe vera extract concentration above 0.5% (v/v), and 1 L/min CO2 flow rate, a rhombohedral calcite and aragonite composite with a polycrystalline dumbbell-like structure with radiating ends was produced. The morphology, particle size, and polymorphs of the CaCO3 crystals could be further tuned by varying the concentrations of the aloe vera extract. The synthesized PCC had a particle in the size range of 120–200 nm.

Synthesis of precipitated Calcium Carbonate (PCC) From Lime Rock Nature Methods Caustic Soda (Studies Concentration HNO3)

The limestones was abundant in Tuban, East Java and have high calcium mineral content. Nevertheless, in the economic value, limestone have low price. Aim the research is prepare Precipitated Calcium Carbonate (PCC) by caustic soda method. In this method, calcium was dissolved in HNO3 with different concentration (2, 4,6, 8 M). The Filtrate obtained then was added by Na2CO3 1 M to get PCC. As the results, The white PCC obtained with the highest rendement is 64,7% when added HNO3 6M. Analysis of functional group by FTIR show that there were strong absorption in the 844,76; 912,27 dan 1411,40 cm-1 that indicated carbonate group. Analysis of Cristallinity by XRD show that there were the peak characteristic of 2 on 29,50˚; 36,07˚ dan 39,50˚that representative calcite structure. SEM-EDX Analysis show that PCC have a mixing structure of calcite and vaterite. Keywords: limestone, PCC, caustic soda

Precipitated Calcium Carbonate Synthesis by Simultaneous Injection to Produce Nano Whisker Aragonite

The synthesis of pure calcium carbonate nanocrystals was achieved using a simultaneous injection method to produce nano particles of uniform size. These were characterized using scanning electron microscopy and powder X-ray diffraction. The nano particles were needle-shaped aragonite polymorphs, approximately 100-200 nm in length. The aragonite polymorph of calcium carbonate was prepared using aqueous solutions of CaCl2 and Na2CO3, which were injected simultaneously into double distilled water at 50°C and then allowed to react for 1.5 h. The resulting whisker-type nano aragonite with high aspect ratio (30) is biocompatible and potentially suitable for applications in light weight plastics, as well as in the medical, pharmaceutical, cosmetic and paint industries. Key words: Nano aragonite whiskers, Simultaneous Injection Method, Aspect ratio, PCC

LCCO2 analysis of wood-containing printing paper by mixed ratio of de-inked pulp and BTMP

Recently, there are growing interests on carbon emissions related in climate change which is worldwide emerging important issue. Some research works are now carrying out in order to reduce the carbon emission in pulp and paper industries by the synthesis of precipitated calcium carbonate using the exhaust carbon dioxide from combustion furnace or incinerator. However, for solving the original problems on carbon emission, we need to consider the analysis of basic methodology on <TEX>$CO_2$</TEX> through the process efficiencies. There are two general tools for carbon emissions; one is the greenhouse gas inventory and the other is <TEX>$LCCO_2$</TEX> method which is applied to particular items of raw materials and utilities in unit process. In this study, the carbon emissions in wood-containing printing paper production line were calculated by using <TEX>$LCCO_2$</TEX> method. The general materials and utilities for paper production, such as fibrous materials, chemical additives, electric power, steam, and industrial water were analyzed. As the results, <TEX>$Na_2SiO_3$</TEX> showed the highest loads in carbon emissions, and the total amount of carbon emissions was the highest in electricity. In the production line of printing paper using de-inked pulp and BTMP, as the mixing ratio of DIP was higher, the carbon emissions were decreased because of high use of electric power in TMP process.

Effect of Several Factors on the Synthesis of Calcium Hydroxide Prepared by Spray Drying Method Using Limestone

The purpose of this work is to influence of CaO concentrations of 5.0 wt.% and 10.0 wt.%, slurry feeding rate of 200~400 /min, rotating rate of drum of 5,000 and 10,000 rpm, inlet and outlet temperature on the synthesis of Ca(OH)2 powder, and the synthesis of precipitated calcium carbonate by carbonation process using Ca(OH)2 prepared by spray drying method. As the feeding rate of slurry was increased, the particle size of Ca(OH)2 was decreased. Regardless of rotating rate of drum, when the concentration of CaO was 5.0 wt.% and 10.0 wt.%, the morphology of Ca(OH)2 showed spherical shape of 10~30 μm and 20~60 μm, respectively. The specific surface area of synthesized Ca(OH)2 was 27~30 m2/g. When the initial reaction temperature was 11 °C and 30 °C, the shape and particle size of precipitated calcium carbonate synthesized in the carbonation process showed the rectangular shape of 0.1~0.4 μm and the spindle shape of 0.5~1.0 μm, respectively.

The Effect of Molar Ratio Ca/Al on Synthesis of Aragonite Precipitated Calcium Carbonate

ABSTRACT Effect of aluminum ion on synthesis of precipitated calcium carbonate by carbonation process was investigated with changing its amount of addition, mixing condition and reaction temperature. 0.2 mole Ca(OH)2 was added to 2L of 0.1M NaAlO2 aqueous solution, and then calcium carbonate was synthesized by blowing CO2 gas into the suspension. For Ca/Al>1(molar ratio), only calcite powder was precipitated, for Ca/Al=1, both calcite and aragonite were precipitated and for Ca/Al>l, the content of aragonite decreased. The raising of reaction temperature made the pH of the suspension lowered, and it resulted in progress of formation of aragonite phase at 80°C.

Synthesis of micrometer to nanometer CaCO3 particles via mass restriction method in an emulsion liquid membrane process.

A mass restriction principle has been applied for the synthesis of precipitated calcium carbonate (PCC) with particle sizes from nanometer to micrometer via a simple emulsion liquid membrane (ELM) process. The internal liquid droplets in ELM were designed as individual microreactors in which the concentration and the total mass of the reaction chemicals were carefully mediated. Instrumental analysis, such as Fourier transform infrared (FTIR), wide X-ray diffraction (WXRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis, confirmed a predominant calcite form of the final product via this process. The comparison of calculated particle sizes with that obtained from experimental measurements using dynamic light scattering (DLS), transmission electron microscopy (TEM) and SEM analysis suggested that approximately one PCC particle was formed in one water-in-oil (w/o) droplet.