Ion Exchange Performance of Zeolite for Removal of Calcium in a CKD Leaching Solution

이예환,장영희,김지유,엄한기,이상문,김성수 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

In the study, zeolite was used as an ion-exchange substance to remove calcium in cement kiln dust (CKD) leachate by an ion-exchange method. The CKD leachate was contained a high concentration of potassium chloride and 1,000 mg/L of calcium. Five types of zeolite were used, and 13X zeolite was observed the high calcium removal performance. We confirmed that a calcium removal amount of 13X zeolite was 13.4 mg of Ca²⁺/g Zeolite by ICP analysis. The high performance of 13X zeolite were attributed low Si/Al ratio and binding with sodium ion.

천연 제올라이트를 이용한 고농도의 칼슘이온 제거 : 이온교환속도 및 이온교환능 Kinetics and Isotherm

안봉규,오재일,윤석민,임남웅 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

The concentrated calcium removal from industrial wastewater by natural zeolite was examined to reduce inhibitory effects of those ions on the biological treatment in down-stream. It is well known that natural zeolite possesses good cation exchange capacity. Kinetic studies by using a batch-type methods demonstrated that the adopted particle size(1-2, 2-2.8, 2.8-4㎜) of zeolites showed similar exchange trends of calcium ions and showed relatively fast exchange reaction within 1 hour in spite of various zeolite dosages. The influence of the temperature on the ion-exchange capacity (isotherm) was examined. It was found that calcium exchange capacity(4.464㎎-Ca^2+/g-zeolite) at low temperature of 5℃ was double up to 9.225㎎-Ca^2+/g-zeolite at the range of 22-40℃. However, ion exchange efficiencies were similar at each condition of pH 6,7,8,10.

이산화탄소 압력순환흡착을 위한 칼슘 이온교환 Y 제올라이트의 작업용량과 선택계수 향상

김문현(Moon Hyeon Kim) 한국청정기술학회 2018 청정기술 Vol.24 No.1

25 ℃에서 CO₂ 흡착을 위한 작업용량과 CO₂/CO 선택계수를 현저하게 향상시키기 위하여 서로 다른 전하와 이온반경을 갖는 Na+, Li+, Ca<SUP>2+</SUP>와 Cu2+로 이온교환된 Y 제올라이트들이 연구되었다. 매우 소량인 0.012% Ca<SUP>2+</SUP>로 이온교환된 NaY는 7회의 반복적인 CO₂ 흡착/탈착 싸이클 동안에도 완전히 가역적이었으므로 기존에 보고된 것들과는 달리 표면에 카보네이트는 생성되지 않는 것으로 생각된다. 4 bar 이상에서 2.00% CaY, 1.60% CuY와 1.87% LiY 모두 NaY와 매우 유사한 CO₂ 흡착성능을 보였다할지라도 그보다 낮은 압력에서는 이들의 흡착능은 감소하였고 그 정도는 금속이온들의 종류에 의존하였다. 0.5 ~ 2.5 bar에서 CO₂ 흡착성능은 NaY > 1.60% CuY > 2.00% CaY > 1.87% LiY의 순으로 나타났는데, 이들 모두 동일한 faujasite 골격과 약 2.6의 Si/Al 비율을 가지므로 골격, 골격조성, 유효세공크기와 채널구조에 있어서 차이는 없기 때문에 약한 루이스산의 특성을 갖는 CO₂의 구별되는 흡착거동은 이온교환에 따른 국부염기도와 흡착 포텐셜 에너지의 변화 때문일 것이다. CO₂ 흡착과는 다른 경향성이 CO 흡착에서 나타났고 이는 보다 약한 사극자 상호작용 때문이다. 0.012 ~ 5.23% Ca 함량을 갖는 Y 제올라이트에 CO₂와 CO 흡착 시 Ca 함량에 따른 현저한 의존성이 존재하였는데 0.05% 이하에서 CO₂ 흡착능은 증가한 반면에 그 이상에서는 감소하였다. 이러한 경향에도 불구하고 Ca 함량의 증가와 함께 작업용량과 CO₂/CO 선택계수는 현저히 증가하였고, 5.23% CaY의 경우 작업용량은 2.37 mmol g-1, 선택계수는 4.37이었는데 본 연구에서 얻어진 작업용량은 문헌에 보고된 벤치마크와 유사한 수준이었다. Y zeolites with different extra-framework cations, such as Na+, Li+, Ca<SUP>2+</SUP>, and Cu<SUP>2+</SUP>, with different charge and ionic radius have been investigated to greatly enhance a working capacity (W) of CO₂ adsorption at 25 ℃ and a CO₂/CO selectivity factor (S). A sample of NaY with a very small amount of 0.012% Ca<SUP>2+</SUP> was fully reversible for seven times repeated CO₂ adsorption/desorption cycles, thereby forming no surface carbonates unlikely earlier reports. Although at pressures above 4 bar, 2.00% CaY, 1.60% CuY and 1.87% LiY all showed a CO₂ adsorption very similar to that measured for NaY, they gave a significant decrease in the adsorption at lower pressures, depending on the metal ion. At 0.5 ~ 2.5 bar, the extent of CO₂ adsorption was in the order NaY > 1.60% CuY > 2.00% CaY > 1.87% LiY. All the Na+-based metals-exchanged zeolites have a FAU (faujasite) framework and a Si/Al value near 2.6; thus, there is no discernible difference in the framework topology, framework chemical compositions, effective aperture size, and channel structure between the zeolite samples. Therefore, the distinctive behavior in the adsorption of CO₂ with a character as a weak Lewis acid is associated with the site basicity of the zeolites, and the interaction potentials of thecations. Different trend was shown for a CO adsorption due to weaker quadrupole interactions. Adsorption of CO₂ and CO on samples of CaY with 0.012 to 5.23% Ca disclosed a significant dependence on the Ca loading. The CO₂ adsorption increased when the cation exists up to ca. 0.05%, while it decreased at higher Ca amounts. However, values for both W and S could greatly increase as the bare zeolite is enriched by Ca<SUP>2+</SUP> ions. The 5.23% CaY had W = 2.37 mmol g-1 and S = 4.37, and the former value was comparable to a benchmark reported in the literature.

Synthesis and Single-crystal Structure of Fully Dehydrated Fully Ca2+-exchanged Zeolite Y (FAU), |Ca35.5|[Si121Al71O384]-FAU

서성만,최식영,서정민,Ki Jin Jung,허남호,임우택 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.8

The single-crystal structure of |Ca35.5|[Si121Al71O384]-FAU, Ca35.5Si121Al71O384 per unit cell, a = 24.9020(10) Å, dehydrated at 673 K and 2 × 10-6 Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd 3m at 294 K. The large single crystals of zeolite Y (Si/Al = 1.70) were synthesized up to diameters of 200 μm and Ca2+-exchanged zeolite Y were prepared by ion exchange in a batch method of 0.05 M aqueous Ca(NO3)2 for 4 hrs at 294 K. The structure was refined using all intensities to the final error indices (using only the 971 reflections for which Fo > 4σ(Fo)) R1 = 0.038 (based on F) and R2 = 0.172 (based on F2). About 35.5 Ca2+ ions per unit cell are found at an unusually large number of crystallographically distinct positions, four. Nearly filling site I (at the centers of the double 6-rings), 14.5 octahedrally coordinated Ca2+ ions (Ca-O = 2.4194(24) Å and O-Ca-O = 87.00(8) and 93.00(8)o) are found per unit cell. One Ca2+ ions per unit cell is located at site II’ in the sodalite cavity and extends 0.50 Å into the sodalite cavity from its 3-oxygen plane (Ca-O = 2.324(13) Å and O-Ca-O = 115.5(10)o). The remaining twenty Ca2+ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 10 and 10 ions, respectively. Each of these Ca2+ ions coordinates to three framework oxygens, either at 2.283(3) or 2.333(5) Å, respectively, and extends either 0.24 or 0.54 Å, respectively, into the supercage from the three oxygens to which it is bound. In this crystal, site I is the most populated; sites II’ and II are only sparsely occupied. Ca2+ appears to fit the octahedral site I best. No cations are found at sites III or III’, which are clearly less favorable for Ca2+ ions in dehydrated zeolite Y.

칼륨이온 공존 수용액 내 칼슘이온 제거를 위한 제올라이트 개질 연구

이예환,김지유,이주열,박병현,김성수 한국공업화학회 2019 공업화학 Vol.30 No.6

본 연구는 제올라이트를 이용한 칼슘이온 제거에 대한 것으로 시멘트 산업에서 발생하는 cement kiln dust를 이용한CaCO3 제조 공정의 문제를 해결하기 위함이다. 칼슘이온을 제거하기 위하여 제올라이트를 개질하여 사용하였으며결합 양이온 및 구조를 고려한 최적 제올라이트 선정, 칼슘이온 제거 성능 평가, 개질 용액의 종류 및 농도의 영향, K 공존 시 제거 선택도 평가에 대해 연구를 수행하였다. 5종의 제올라이트 중 13X 제올라이트의 칼슘 이온 제거 성능이 가장 우수함을 확인하였고 NaCl 대신 KCl을 개질 용액으로 사용하였을 때 칼슘이온 제거 성능이 증진되는 것을확인할 수 있었다. 본 연구는 탄산화 공정의 문제 해결, 고농도의 KCl 회수 기술의 바탕이 될 것으로 판단된다.

Synthesis and Single-crystal Structure of Fully Dehydrated Fully Ca²⁺exchanged Zeolite Y (FAU), |Ca_35.5|[Si₁₂₁Al₇₁O₃₈₄]-FAU

Seo, Sung-Man,Choi, Sik-Young,Suh, Jeong-Min,Jung, Ki-Jin,Heo, Nam-Ho,Lim, Woo-Taik Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.8

The single-crystal structure of |$Ca_{35.5}$|[$Si_{121}Al_{71}O_{384}$]-FAU, $Ca_{35.5}Si_{121}Al_{71}O_{384}$ per unit cell, a = 24.9020(10) $\AA$, dehydrated at 673 K and 2 ${\times}\;10^{-6}$Torr, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd$\overline{3}$m at 294 K. The large single crystals of zeolite Y (Si/Al = 1.70) were synthesized up to diameters of ${\mu}m\;and\;Ca^{2+}$-exchanged zeolite Y were prepared by ion exchange in a batch method of 0.05 M aqueous Ca($NO_3)_2$ for 4 hrs at 294 K. The structure was refined using all intensities to the final error indices (using only the 971 reflections for which $F_o\;>\;4{\sigma}(F_o))\;R_1$ = 0.038 (based on F) and $R_2$ = 0.172 (based on $F^2$). About 35.5 $Ca^{2+}$ ions per unit cell are found at an unusually large number of crystallographically distinct positions, four. Nearly filling site I (at the centers of the double 6-rings), 14.5 octahedrally coordinated $Ca^{2+}$ ions (Ca-O = 2.4194(24) $\AA$ and O-Ca-O = 87.00(8) and 93.00($8^o$) are found per unit cell. One $Ca^{2+}$ ion per unit cell is located at site II’ in the sodalite cavity and extends 0.50 $\AA$ into the sodalite cavity from its 3-oxygen plane (Ca-O = 2.324(13) $\AA$ and O-Ca-O = 115.5(10)o). The remaining twenty $Ca^{2+}$ ions are found at two nonequivalent sites II (in the supercages) with occupancies of 10 and 10 ions, respectively. Each of these $Ca^{2+}$ ions coordinates to three framework oxygens, either at 2.283(3) or 2.333(5) $\AA$, respectively, and extends either 0.24 or 0.54 $\AA$, respectively, into the supercage from the three oxygens to which it is bound. In this crystal, site I is the most populated; sites II’ and II are only sparsely occupied.$Ca^{2+}$+ appears to fit the octahedral site I best. No cations are found at sites III or III’, which are clearly less favorable for $Ca^{2+}$ ions in dehydrated zeolite Y.

환경 유해 부산물 누출이 없는 지반 보강용 효소 기반 탄산칼슘 침전 기법 연구

이승형(Lee, Seung-Hyung),김종민(Kim, Jong-Min) 한국지반공학회 2021 한국지반공학회논문집 Vol.37 No.4