Effects of Anionic Polyacrylamide on Carbonation for the

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Effects of Anionic Polyacrylamide on Carbonation for the Crystallization of Precipitated Calcium Carbonate Tai-Ju Lee, Hyoung-Jin Kim, Seok Jun Hong, and Jung Yun Park Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/cg501419e • Publication Date (Web): 29 Jan 2015 Downloaded from http://pubs.acs.org on February 18, 2015

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Crystal Growth & Design

Effects of Anionic Polyacrylamide on Carbonation for the Crystallization of Precipitated Calcium Carbonate Tai Ju Lee, Seok Jun Hong1), Jung Yoon Park1), and Hyoung Jin Kim1)* Changgang Institute of Paper Science & Technology, Chuncheon-si, Gangwon-Do, Republic of Korea 1)

Department of Forest Science, Kookmin University, 77, Jeongneung-ro, Seungbuk-gu, Seoul, Republic of Korea

ABSTRACT: The effects of different types of anionic polyacrylamide (PAM) on crystallization behavior of precipitated calcium carbonate (PCC) prepared via carbonation using calcium hydroxide and carbon dioxide gas. The percentage of aragonite phase increased higher reaction temperature. The use of anionic PAM resulted in the formation of larger PCC aggregates than in the case of PCC crystallized without anionic PAM. This outcome resulted from a contraction of the PAM coils due to the electrostatic screening and counterion condensation effects. The carbonate ions were combined with aggregated calcium ions. Furthermore, the carbonation reaction time could also be reduced by the addition of anionic PAM. Keywords: PCC (precipitated calcium carbonate), carbonation, anionic polyacrylamide, particle size, morphology, polymorph

1. Introduction Calcium carbonate exists mainly as six different polymorphs: amorphous calcium carbonate (ACC), calcium carbonate hexahydrate, calcium carbonate monohydrate, vaterite, aragonite, and calcite, where the thermodynamic stability increases from ACC to calcite. Calcium carbonate particles have three crystal structures, which are classified as rhombic calcite, needlelike aragonite, and spherical vaterite. Calcite is the most stable phase at room temperature under normal atmospheric conditions, while aragonite and vaterite are metastable polymorphs that readily undergo transformation to the stable calcite phase.1 The applications of precipitated calcium carbonate (PCC) is determined by the morphology, structure, size, specific surface area, brightness, oil adsorption, chemical purity, etc., of PCC. The particle morphology and size are particularly important parameters for such applications.2, 3. Consequently, control of the particle size and shape of PCC is extensively studied. Certain studies have demonstrated that the morphology of PCC can be controlled by the use of various types of additives such as polyvinyl alcohol (PVA)4, polystyrene sulfonate (PSS)5, poly(acrylic acid)6, 7 or their derivatives8, 9 biopolymers10, 11, and polyacrylamide (PAM)12 and so on. Specifically, polyacrylamides (PAMs) have been used in PCC crystallization in order to control the morphology and particle size during the carbonation process. Polyacrylamide (PAM) is a universal compound that is widely utilized in various fields, such as water treatment, mineral processing, soil recovery, paper industry, and biological applications and so on. In papermaking, PAM is used as a dry strength and retention aid. It is believed that the polar amide groups in PAM form hydrogen bonds with the hydroxyl groups of cellulose.

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Yu et al12 synthesized nano-scale CaCO3 by the addition of PAM. The PCC particles were approximately 50 nm in diameter and 1 μm long. They showed that the synthesis of nano-scale CaCO3 was influenced by the reaction time, pH, temperature, and the reactants. In particular, increasing the reaction time led to the production of hollow vaterite hexagonal calcium carbonate. Wang et al13 studied the synthesis of nano-size acicular calcium carbonate by carbonation in the presence of PAM. The process parameters, such as the concentration of PAM and temperature, were varied to study their influence on the morphology and crystal size of the particles. The calcium carbonate synthesized in the presence of PAM comprised a mixture of acicular aragonite and cubic calcite. Chuajiw et al.14 studied the effect of aliphatic organic additives including amines, diamines, and amino acids on the morphology of precipitated calcium carbonate. Amorphous calcium carbonate, vaterite, aragonite, and calcite were observed in the presence of additives that may induce hydrophobic interaction between the organic additives and inorganic calcium carbonate surface. 15

The aim of this study is to control the morphology of PCC using anionic PAM. The morphological changes of PCC are intensively studied via UHR-SEM and the crystallization is evaluated by means of X-ray diffraction. Based on these analyses, the effects of anionic PAM on shape and size of calcium carbonate and carbonation process were studied.

Experimental procedure Materials. Calcium hydroxide (Ca(OH)2, >95% purity, DAE JUNG Science, Gyonggi-do, Korea) was used as a raw material. Distilled water was used for preparation of the Ca(OH)2 slurries. Carbon dioxide gas (CO2, >99% purity, Dong-A Specialty Gases Scientific Corp., Seoul, Korea) was used for carbonation. The Anionic polyacrylamides described in Table 1 were used to control the crystallization behavior of PCC during carbonation. The symbols in Table 1 are used to indicate the properties of the anionic polyacrylamides.

Table 1. Molecular weight and charge density of anionic polyacrylamides Symbol

Properties

Molecular weight

Charged groups, %

L

high Mw, low charge

13.0 × 106

10

H

high Mw, high charge

13.0 × 106

25

Instrument for PCC crystallization. Figures 1 and 2 show the inner and outer configurations of the instrument used for synthesis of PCC by carbonation. Figure 1 shows the outside of the mixing batch system and impeller. The double-blade impeller used to stir the calcium hydroxide slurry was connected to a motor that can control the mixing rate. A vent was installed on the top of the batch cover for safety during carbonation. The outer region of the batch consists of the vat, heating coil, and control box. The vat is made of stainless steel and the heating coils were embedded into the wall of the vat. The pH, electrical conductivity, temperature, and mixing rate could be adjusted using the control board in front of the mixing batch. As


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shown in Figure 2, baffles were installed in the wall of the vat to facilitate homogeneous mixing of the calcium hydroxide slurry. A drain valve was located at the bottom of the batch and a gas injector was located on the back side. The drain valve is used to draw off the PCC slurry after reaction. Carbon dioxide gas was ejected from the tanks and injected into the slurry through an air generator. The flow rate of the gas was controlled by a mass flow controller. In addition, changes in the pH and electrical conductivity were monitored by serial data interface software (iSTEK, Seoul, Korea) during the reaction for analysis of the carbonation process.

Figure 1. Impeller and the outside of PCC mixing batch system.

Figure 2. Inside the PCC mixing batch system.

Experimental procedures. Crystallization of PCC was performed via carbonation process. Predetermined amount of anionic PAM was added to 10 L distilled water. The mixture was injected into the mixing batch system. Calcium hydroxide was added to the mixing batch in concentrations of 10 and 50 g/L in respective



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syntheses, and the calcium hydroxide powder and aqueous PAM were mixed at a given shear force (1000 rpm). Carbon dioxide was then injected into the solution at a rate of 2 L/min in order to crystallize PCC. During this stage, the temperature was also controlled at 20 and 40 °C. The details of the experimental conditions are presented in Table 2.

Instrumental analysis. X-ray diffraction (D8 ADVANCE, BRUKER, GERMANY) was used to analyze the polymorphic conformation of calcium carbonate. Calcium carbonate samples for XRD measurement were taken by electrical conductivity in order to monitor change of morphology during carbonation process. The scan step and repeat time were 2 cm-1 per second and 36 times, respectively. The step size was set to 0.2° and the scan range was 10~90°; the step time was 0.2 seconds. X-ray diffraction patterns of the finely powdered samples were acquired using Cu Kα radiation (40 kV and 30 mA). The morphology and the size of the PCC aggregates were investigated by means of ultra high resolutionscanning electron microscopy (UHR-SEM, Hitachi S-4800, Japan) and by using a Mastersizer 2000 instrument equipped with a HydroMU cell (Malvern instrument, UK). Unreacted anionic PAM was quantified by analysis of the chemical oxygen demand (COD) after carbonation in order to estimate the efficiency of the process. Centrifugation of the PCC slurry sample was performed at 3000 rpm for 20 minutes. After centrifugation, the chemical oxygen demand was measured by the COD Cr method. The vial contents were digested at 150 °C for 2 hours. After cooling to room temperature, the COD value was measured using a COD spectrophotometer (Odyssey, DR/2500, HACH, USA).

Table 2. Conditions for synthesis of PCC with anionic PAM a

: based on weight of calcium hydroxide

Experimental conditions Sample

H20 H40 L20 L40

Ca(OH)2 conc., g/L 10 50 10 50 10 50 10 50

CO2 flow rate, L/min

Anionic PAM dosage a, %

Temperature, °C

2

0.02

20

2

0.02

40

2

0.02

20

2

0.02

40

a

Based on weight of calcium hydroxide

Results and discussion

Analysis of carbonation process without anionic PAM. Figures 3 and 4 show the pH curves obtained during the carbonation process. Carbonation was initiated under strongly alkaline conditions where the


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electrical conductivity was 8~9 mS/cm. Thus, Ca2+, OH-, HCO32-, CO32-, CaOH+, and CaHCO3- ions were dissolved in the solution. At the end of the carbonation process, the electrical conductivity was below 0.5 mS/cm and the pH value decreased to 7±0.5. Initially, the values decreased very gradually, with the appearance of an inflection point around 7 mS/cm or pH 12~13. The values decreased sharply beyond the inflection point, and the carbonation process was terminated shortly thereafter. The observations can be explained in terms of the basic chemical reaction mechanism of calcium carbonate.16 The respective solubilities of calcium hydroxide and carbon dioxide in water are 1.73 and 1.51 g/L at 20 °C.17, 18 Calcium hydroxide and carbon dioxide were combined in a proportion of 1.15: 1. According to the mechanism mentioned above, in water, calcium hydroxide dissociates into Ca2+ and 2OH-. Ca2+ acts as a calcium source for calcium carbonate. When carbon dioxide dissolves in water, the OH- from calcium hydroxide and the CO2 gas react to form HCO32-. The carbonate anion and water are then generated by reaction of another OHwith HCO32-. Thus, the continuous decline of the pH and the electrical conductivity can be attributed to the solubility and concentration of calcium hydroxide. When all of the calcium hydroxide in a batch is dissolved, a steep decrease of the pH and electrical conductivity values can be observed. Consequently, all ions in the process can be consumed for formation of calcium carbonate or water molecules. Thus, the carbonation process can be summarized as follows: the first stage is pre-nucleation in which the calcium and carbonate ions dissolve gradually. The second stage is nucleation and crystal growth. This stage involves a metastable phase, i.e., formation of crystallization nuclei. With respect to thermodynamics, this stage can be regarded as the rate-determing step. Because the rate of for the carbonation process can be determined by the rate of this stage. . As shown in Figures 4 and 5, the rate of reaction of PCC in this stage is determined by the calcium hydroxide concentration and temperature. The rate of the carbonation reaction under high calcium hydroxide concentration and low temperature conditions was slower than that under low calcium hydroxide and high temperature conditions. Accordingly, the amount of reactive calcium hydroxide and the temperature can be considered as crucial factors for controlling the reaction rate of the system. As mentioned above, temperature is the most important factor in the carbonation process. As shown in Figure 4, the rate of the reaction at high temperature was faster than that at low temperature. The slope of the pH versus time plots with the use of various concentrations of calcium hydroxide was steeper during generation of the metastable phase (2nd stage) at 40 °C than at 20 °C. These results demonstrate that the nucleation rate increases with increasing temperature. Solutes in the supersaturated solution move freely and collide with each other. The collision causes molecules to bounce off or aggregate based on their kinetic energy. Molecular aggregates either become larger or decompose due to collision between the aggregates. The phenomena can be explained based on a thermodynamic model. The activation energy of the system changes due to collision between the molecules. The change in the activation energy depends on the change in the volume and the surface area of the aggregates.19 The interaction can be explained using the following equation:20 ΔG = VΔGv + SAΔGs where V is the volume of the aggregates, SA is the surface area of the aggregates, ΔGv and ΔGs are the change in the activation energy due to the respective changes in the volume and surface area of the aggregates. ΔGs ACS Paragon Plus Environment


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can be considered as the interfacial energy (σ) and ΔGv can be explained as a function of the temperature and concentration of the solution in the liquid-gas system. Therefore, ΔG can be expressed by the following function:20 ΔGV = -4/3πr3 (kT/V) lnS + 4πr2σ where r is the radius of the aggregate, S is the supersaturation, V is the volume of the aggregate, k is Boltzmann’s constant, and T is the absolute temperature. The crystallization of calcium carbonate is an exothermic chemical reaction. Therefore, the reaction state can be expressed as the below equation. If ΔGV is differentiated by the r value, the critical particle size of the nucleus can be expressed by the following equation.21 rc = - 2σ/ΔGV Here, rc is the critical particle size of the nucleus. Based on the above equation, a high ΔGV will lead to a low critical particle size (rc). The activation energy for the critical particle size (ΔGC) is expressed as: ΔGC = 16πr3 / 3(ΔGV)2 If the temperature is high during the process, the absolute value of ΔGv will be large. Thus, the reaction time becomes fast because the overall ΔGC decreases. Additionally, the classical nucleation theory modified by the Arrhenius equation adequately explains the results. The equation demonstrates that the kinetic rate constant k depends on the temperature (T) throughout the reaction.21 k = A∙e(-Ea / RT) Here, k is the rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and T is the absolute temperature. When the temperature increases, the activation energy decreases according to the Arrhenius equation. Consequently, the rate constant was large (fast reaction) at high temperature.


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Figure 3. Change of pH during carbonation using various concentrations of calcium hydroxide.

Figure 3. Change of pH during carbonation at different temperatures.

Analysis of carbonation process with anionic PAM. Figure 5 shows the variation of the pH and electrical conductivity during the carbonation process employing anionic PAM. The reaction time for synthesis of PCC with anionic PAM was faster than that without anionic PAM. This is related to the efficiency of aggregation based on the conformation of anionic PAM. During the carbonation process employing anionic PAM, ionic species from calcium hydroxide and carbon dioxide have a definite influence on the conformation of PAM, given the electrostatic attraction and repulsion between anionic PAM and the ionic substances. The ACS Paragon Plus Environment


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molecules in anionic PAM are believed expand due to the electrostatic repulsion between the equally charged segments.22 In the presence of a high concentration of calcium hydroxide, the coils were expanded to a lesser extent due to the increased screening of the electrostatic force between the segments. With the addition of high molecular weight PAM, the calcium ions aggregated via the anionic functional groups in the acrylamide molecules. Thus, anionic PAM assumed a coiled conformation with the calcium ions in the slurry. Finally, the calcium ions underwent aggregation due to a conformational change of anionic PAM. This aggregation enhanced the nucleation rate given that the aggregate size could increase easily until the critical particle size for nucleation was achieved.23 Therefore, anionic PAM enhanced the rate of the carbonation process by promoting aggregation of the calcium ions.

Figure 5. Variation of pH during carbonation in response to addition of anionic PAM (dosage of anionic PAM: 0.02% based on calcium hydroxide, Ca(OH)2: 50 g/L; Temp.: 20 °C).

Morphology of PCC with anionic PAM. The morphological changes of PCC in the presence of 0.02% of the different anionic PAMs with variation of the temperature and concentration of calcium hydroxide was monitored by XRD Figures 6–7. X-ray diffraction was used to analyze the crystallization behavior of calcium carbonate with anionic PAM. Samples for XRD measurement were obtained at a predetermined value of the electrical conductivity during the carbonation process in order to observe morphological changes of the calcium carbonate crystals. As mentioned above, the initial electrical conductivity was 8~9 mS/cm. During the reaction, the electrical conductivity decreased to reach below 0.5 mS/cm at the end of the process. The X-ray diffraction data acquired for samples prepared at different experimental temperatures and the fraction of calcite and aragonite were analyzed using the equations suggested by Kontoyannis et al.24 Calcite was primarily formed at 20 °C, and some aragonite was observed at a carbonation temperature of 40 °C. The reproducibility of the X-ray diffraction data was evaluated based on ten replicate measurements. Assuming that the sum of the molar ratio ACS Paragon Plus Environment

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of calcite, aragonite, and vaterite is 1, the molar fractions in a calcium carbonate specimen may be determined from the following relationships.24 (6)

(7) (8) Here, XC, XA, and Xv are the molar ratio of calcite, aragonite, and vaterite in the PCC mixture; IC and IA are the intensity of the calcite peaks at 2Ɵ = 29.4° and of aragonite at 2Ɵ = 45.6°. The intensity of the {104} peak of calcite at 29.5° was 100% at 20 °C, whereas the intensity of the {104} peak of calcite decreased and that of the {221} peak of aragonite at 45.9° increased to 24±0.39% as the reaction temperature increased. These results were also consistent with the FE-SEM images in Figure 9 that show changes in the morphology of PCC with addition of the polyelectrolyte. As shown in Figure 9, acicular PCC particles were generated by increasing the reaction temperature. Aragonite was clearly evident with the use of a relatively high concentration of calcium hydroxide at 40 °C. Aggregation due to electrostatic attraction between the calcium ions and the polyelectrolyte was observed.

Figure 6. XRD patterns of PCC synthesized with high molecular weight and low charge anionic PAM with variation of the electrical conductivity during carbonation. (Temp.: 20 °C).



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Figure. 7. XRD patterns of PCC synthesized with high molecular weight and low charge anionic PAM with variation of the electrical conductivity during carbonation. (Temp.: 40 °C).

Figure 8. SEM images of PCC synthesized with high molecular weight and low charge anionic PAM at different temperatures (concentration of calcium hydroxide: 50 g/L).

Aggregate size of PCC crystallized with anionic PAM. Figure 9 shows the average aggregate size and size distribution of the PCC, determined by the light diffraction scattering technique. The average aggregate size of the PCC synthesized using 10 g/L of calcium hydroxide was larger than that obtained with 50 g/L of calcium hydroxide. In terms of the charge density of anionic PAM, the particles of PCC that were crystallized in the presence of low charge PAM were larger than those obtained with highly charged PAM. Increasing the ion concentration led to further condensation of the coils of the polyelectrolyte. The salt effect resulted in a contraction of the coils in response to the electrostatic screening and counterion condensation effects.25


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Figure 9. Aggregate size of PCC synthesized with anionic PAM.

Evaluation of residual anionic PAM. The residual anionic PAM was analyzed based on the chemical oxygen demand. From the above results, it was deduced that anionic PAM bonds calcium ions via electrostatic attractive force. Unreacted anionic PAM remaining in the solution may cause environmental problems or negatively affect the PCC manufacturing process. As shown in Table 3, the COD was definitely low. Thus, the amount of anionic PAM used in the process was appropriate and for the eco-friendly synthesis of PCC.

Table 3. Chemical oxygen demand of supernatant of PCC sample Types of filler

Parameter Chemical oxygen demand, ppm

HH20

HH40

HL20

N.D.

N.D.

8.0

HL40 11.3 N.D.: none detected

Conclusion The crystallization of PCC with anionic PAM was evaluated in this study. The amount of the aragonite phase in PCC increased with increasing reaction temperature; therefore, a high reaction temperature could decrease the activation energy (i.e., ∆Ecritical particle size). The use of anionic PAM during PCC synthesis led to aggregation of the PCC particles. Furthermore, the reaction time was shortened by addition of anionic PAM. The PAM promoted aggregation of unreacted calcium hydroxide particles and calcium carbonate nuclei, leading to an increase in aggregate size and a reduction of the reaction time for the carbonation process due to facile attainment of critical nucleation.



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Acknowledgements This research was supported by the Energy Efficiency and Resources division of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) funded by the Ministry of Knowledge Economy, Republic of Korea (No. 2010T100200471).

References

(1) El-sheikh, S. M.; El-sherbiny, S.; Barhoum, A.; Deng, Y. Colloids. Surf. A 2013, 422, 44-49. (2) Wang, L. F.; Sondi, I.; Matijevic, E. J. Colloid Interf. Sci. 1999, 218, 545-553. (3) Yu, J. G.; Lei, M.; Cheng, B.; Zhao, X. J. J. Solid State Chem. 2004, 177, 681-689. (4) Lakshminarayanan, R.; Valiyaveettil, S.; Loy. G. L. Cryst. Growth Des. 2003, 3, 953-958. (5) Jada, A.; Verraes, A. Colloid. Surf. A 2003, 219, 7-15. (6) Yue, L. H.; Jin, D. L. Chinese Sci. Bull. 2004, 49, 235-239. (7) Ulcinas, A.; Butler, M. F.; Heppenstall-Butler, M.; Singleton, S.; Miles, M. J. J. Cryst. Growth 2007, 307, 378-385. (8) Liu, Q.; Wang, Q.; Xiang, L. Appl. Surf. Sci. 2008, 254, 7104-7108. (9) Lei, M.; Tang, W. H.; Yu, J. G. Mater. Res. Bull. 2005, 40, 656-664. (10) Kirboga, S.; Oner, M. Powder. Technol. 2013, 249, 95-104. (11) Guo, M.; Li, Q.; Ye, X. S.; Wu, Z. J. Powder Technol. 2010, 200, 46-51. (12) Yu, Q.; Ou, H. D.; Song, R. Q.; Xu, A. W. J. Cryst. Growth 2006, 286, 178-183. (13) Wang, C. Y.; Zhao, J. Z.; Zhao, X.; Bala, H.; Wang, Z. C. Powder Technol. 2006, 163, 134-138. (14) Chuajiw, W.; Takaton, K.; Igarashi, T.; Hara, H.; Fukushima, Y. J. Cryst. Growth 2014, 386, 119-127. (15) Jung, W. M.; Kang, S. H.; Kim, W. S.; Choi, C. K. Chem. Eng. Sci. 2000, 55, 733-747. (16) Farhad, A.; Esfahan, Z. M. Int. Dent. J. 2005, 55, 293-301. (17) Gontard, N.; Thibault, R.; Cuq, B.; Guilbert, S. J. Agric. Food Chem. 1996, 44, 1064-1069. (18) Lin, R. Y.; Zhang, J. Y.; Zhang, P. X. J. Cryst. Growth 2002, 245, 309-320. (19) Whitten, K. W.; Raymond, E. D; Larry Peck, M. In Textbook of General Chemistry, Harcourt College Publishers; California, 2000; Chapter 2, pp 542-543. (20) De Yoreo, J. J.; Vekilov, P. G. Rev. Mineral. Geochem. 2003, 54, 57-93. (21) Sundberg, R. Chemometr. Intell. Lab. 1998, 41(2), 249-252. (22) Kamiyama, Y.; Israelachvili, J. Macromolecules 1992, 25, 5081-5088. (23) Gebauer, D.; Völkel, A.; Cölfen, H. Science 2008, 322, 1819-1822. (24) Kontoyannis, C. G.; Vagenas, N. V. Analyst 2000, 125, 251-255. (25) Roiter, Y.; Jaeger, W.; Minko, S. Polymer 2006, 47, 2493-2498.


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For Table of Contents Use Only

Effects of Anionic Polyacrylamide on Carbonation for the Crystallization of Precipitated Calcium Carbonate Tai Ju Lee, Seok Jun Hong1), Jung Yoon Park1), and Hyoung Jin Kim1)*

A

B

Calcium carbonate crystallized with anionic PAM at 20°C (A) and at 40°C (B)

Synopsis The morphology of calcium carbonate crystallized with anionic PAM is a mixture with aragonite and calcite. Aragonite increased under relatively high reaction temperature. Effect of anionic PAM on morphology and size of calcium carbonate have been studied during carbonation.


Effects of Anionic Polyacrylamide on Carbonation for the

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