Kaolin-based geopolymers with various NaOH concentrations
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白陶土 geopolymers 被白陶土的碱激活与一个使活跃之物答案(NaOH 和钠硅酸盐答案的混合物) 生产。NaOH 答案在 614 mol/L 的集中被准备并且在 0.24 的 Na2SiO3/NaOH 集体比率与钠硅酸盐答案被混合准备一个使活跃之物答案。使用的 kaolin-to-activator 答案团比率是 0.80。试图在 Ti4+ 阳离子的 80 条曲线在白陶土 geopolymers 的压缩力量上分析 NaOH 集中的效果的这份报纸被电子探查微量分析， Broeder 优化的 Boltzmann-Matano 方法根据被用来计算 interdiffusion 系数获得。interdiffusion 系数几乎与 Ti4+ 阳离子增加的鼹鼠部分线性地增加了，并且他们在 10121011cm2p 的范围吗？？Cite
This study was conducted to elucidate the effects of NaOH fusion treatment on Na-P1 zeolite synthesis from fly ash and to evaluate its optimal condition. NaOH fusion treatment of fly ash led to Na-P1 zeolite with shorter reaction time and higher quality compared that of simple hydrothermal method. Mixed zeolite phases of Na-P1 and hydroxy sodalite were formed by the fusion treatment below $450^{\circ}C$ , whereas only Na-P1 zeolite was formed above $550^{\circ}C$ . Ratio of NaOH/fly ash, reaction times, fusion temperature and solid/liquid ratio strongly affected the kind and crystallinity of the zeolite formed. The CEC of Na-P1 zeolite formed at the optimum reaction conditions of NaOH/fly ash ratio 0.9 and solid/liquid ratio $1/5.0{\sim}1/7.5$ after NaOH fusion treatment at $550^{\circ}C$ for 2 hours was about $398cmol^+kg^{-1}$ which was 40% higher than those of control products. Therefore, it is clear that NaOH fusion treatment of fly ash in open system could lead to Na-P1 zeolite with high purity.
Sodalite
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Mg2SiO4 was finely prepared by high temperature solid state method using Mg(OH)2.4MgCO3.6H2O and SiO2 as raw materials.The structure of Mg2SiO4 was investigated by XRD and Raman spectroscopy.The optimized conditions for dissolution reaction of Mg2SiO4 in high NaOH content system were investigated by orthogonal test,and the optimal parameters were obtained as follows: reaction temperature of 220 ℃,reaction time of 120 min,liquid-solid ratio of 6:1 and NaOH content of 85%(mass fraction).Based on the optimal experiment,the leaching reaction mechanism of Mg2SiO4 in high NaOH content system was investigated.Raman spectra were measured for the reactions between the silicates and sodium hydroxide in-situ during the alkali dissolution process.Meanwhile,the water-leaching residue of the dissolution products was characterized by X-ray diffractometry.The results show that the bindings Si—O in silicates can be destroyed by aggression of sodium hydroxide,the magnesium ions in Mg2SiO4 can be separated from the silica arrays and liberated in the form of Mg(OH)2 from the silicates.
Sodium hydroxide
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The research aim was to investigate phase development after pozzolanic reaction between metakaolin (MK) and calcium hydroxide (CH) with alkaline and thermal activations. The CH to MK ratio (C/M) of 0.4 generating CaO/SiO 2 of 1.18 was selected in this study. Various concentrations of NaOH solutions (0.01, 0.1, 1, 3, 5 and 10 M) were used. The alkali activated samples were thermally activated at 25 °C, 70 °C, 90 °C and 130 °C for 4 h. Phase development under thermal activation of alkali activated metakaolin based system were investigated. At every temperature, C/M mixtures with 0.01 and 0.1 M NaOH promoted the formations of poorly crystalline calcium silicate hydrate (C-S-H(I)) and calcium aluminosilicate hydrate (CASH) compounds. With 3 and 5 M NaOH activations, sodium aluminosilicate hydrate (NASH) and sodium calcium silicate hydrate (NCSH) was formed. 1 M NaOH was found to be a boundary of phase transformation from C-S-H(I) and CASH to NASH and NCSH. In addition, zeolite X and sodalite appeared when NaOH solution reached 10 M. Thermal activation significantly affected phase development at high concentration of alkaline activation (1-10 M). At 1 M NaOH, NASH compounds in a form of gmelinite and zeolite ZK-14 were found at 70-90 °C. At 3-5 M, katoite was found at 70-130 °C. At 10 M, zeolite X was found at 70-90 °C. Sodalite was also found at 130 °C with 10 M NaOH.
Sodalite
Metakaolin
Sodium aluminosilicate
Calcium silicate hydrate
Sodium hydroxide
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Palm oil boiler ash (BA) has been synthesis with alkaline activator to produce boiler ash based geopolymer. The ratio of BA/alkaline activator and Na 2 SiO 3 /NaOH was fixed for the entire experiment, where six different of NaOH concentration (6 M, 8 M, 10 M, 12 M, 14 M, 16 M) was used to produce geopolymer paste. The compressive strength of geopolymer paste with NaOH concentration 14 M showed the maximum strength which is 13.9 MPa. The strength reduce when geopolymer paste used NaOH concentration more than 14 M. In term of molar oxides SiO 2 /Al 2 O 3 , Na 2 O/SiO 2 and H 2 O/Na 2 O with the increasing of NaOH concentration Na 2 O/SiO 2 ratio also increased but H 2 O/Na 2 O ratio decreased. Meanwhile SiO 2 /Al 2 O 3 ratio remain constant because the BA/alkaline activator and Na 2 SiO 3 /NaOH ratio were constant in this study. The XRD analysis illustrated that the value of 2θ for all geopolymer samples were approximately the same which is 27° with major components of quartz and minor component of cristobalite.
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Sodium hydroxide
Metakaolin
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Shrinkage
Sodium hydroxide
Hydrotalcite
Sodium carbonate
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コールタールピヅチ(C:92.8%)を水酸化ナトリウム(NaOH)溶液中において酸素酸化した。NaOH濃度,反応温度,反応時聞ダ酸素分圧,かきまぜ速度の影響を検討し.水可溶芳香族酸生成の最適条件を明らかにした。最適条件はNaOH濃度1～5mol/kg-H20,反応温度538K程度,反応時間2～3時間,酸素分圧5MPaであり,水可溶芳香族酸収率は仕込ピッチに対し,約50wt%であった。水可溶芳香族酸中には,フタル酸,1,2, 3-ベンゼントリカルボン酸,1,2,3,5-ベンゼンテトラカルボン酸,1,2,4-ベンゼントリカルボン酸をはじめとするベンゼンカルボン酸が多く.18～51wt%に達した.ピッチの酸化過程は定性的には,高炭化度炭の酸化過程と類似するが,最適条件下でも30%程度の未反応ピッチが残留した。ピヅチ反応率を高めるためには,ピッチの前処理などの工夫が必要であると考えられる。
Coal tar
tar (computing)
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Production of Hydrogen by Reaction of Pet-Al Residues of Food Bricks in the Presence of NaOH and KOH
Aluminum being stacked between two layers of polyethylene in food bricks, is a source of hydrogen production highly demanded as energy in our days. With aqueous solutions of NaOH and KOH at concentrations ranging from 1 M to 10 M for T=40, 60 and 80°C, we conclude that the activation energy Ea (NaOH)=36416 J.mol-1 is lower than that of Ea (KOH) at T=60°C and a concentration of 4 M, the reaction is strongly influenced by temperature and concentration. Sodium hydroxide generally promotes more cost-effective reactions. Obtaining an aluminum hydroxide accompanied by salt (NaCl or KCl) after acid treatment of the residual alkaline solution was verified by SEM and IR, thus preserving the nature.
Sodium hydroxide
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This research aimed to synthesize zeolites from perlite obtained from Lopburi Province, Thailand, and from rice husk ash, under hydrothermal condition. The experiments were carried out in an autoclave with SiO 2 /Al 2 O 3 molar ratios of 1 to 40, NaOH concentrations of 1 to 4 N, and starting pressure of 1 atm. The rice husk ash and AlCl 3 ·6H 2 O were used to adjust the SiO 2 /Al 2 O 3 molar ratio. The autoclave was heated with the rate of 1.5 °C/min to the set points of 140 and 170 °C at which it was kept isothermally for 2 h. The results showed that the products detected were analcime, Na-P1, and sodalite octahydrate. However, at very low SiO 2 /Al 2 O 3 ratio and NaOH concentration, no zeolite could be formed at 140 °C. The analcime could be formed at almost all conditions, except at low concentration of NaOH and the SiO 2 /Al 2 O 3 ratio below 25. Furthermore, the Na-P1 could be detected in every area except at high concentration of NaOH and high SiO 2 /Al 2 O 3 ratio at which only analcime and sodalite octahydrate were found. The sodalite octahydrate was formed preferably at high concentration of NaOH and high ratio of SiO 2 /Al 2 O 3 . At temperature of 170 °C, the formation of analcime was enhanced, while the others seemed to be unaffected. Finally, phase diagrams of detected zeolites were constructed.
Analcime
Sodalite
Autoclave
Perlite
Husk
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韓国産河東カオリンを用いてゼオライト合成を行うと,カオリンの構造変化を伴う,従来の低シリカゼオライトでは合成温度が100℃ 以下と低かったため,この温度以下で検討されてきた.しかし,高シリカゼオライトの原料として河東カオリンを用いると,より高い温度での検討が必要であるが,100℃ 以上ではあまり研究されていない.そこで,高シリカゼオライト合成の検討を行う前に,まず合成温度175℃,200rpmで,水分含量変化による河東カオリンからのゼオライト合成とカオリンの構造変化について研究した.その結果,次のようなことが明らかになった.(1)水分含量98%の場合,ソーダライト,ゼオライトA,ゼオライトP1,UnknownTやその混合物が生成した.特にゼオライトAは非常に狭い範囲で生成した。水分含量95%の場合には,単一生成物は得られず,その混合物だけ生成された.(2)処理時間の変化による水分含量(928)%の生成系では,カオリン→ 非晶質相→ ソーダライト→ ゼオライトA→ ソーダライトの経路で変換したが,95%では,カオリン→ カオリンとソーダライトの混合物→ ソーダライトへ変換し,非晶質相を経由しなかった.(3)カオリン中に含まれているSiO3,Al2O3の溶出量は,NaOH濃度が高いほど多くなったが,ゼオライトが生成する領域では逆に減少し,その後一定になることがわかった.(4)河東カオリンのNaOH水溶液による非晶質化速度について,0.2M(1M=1moldm-3)で処理したときは,非晶質化速度定数が0.0018min-1,1.5Mの方は0.0590min-1で,非晶質化速度の差が約30倍もあることがわかった.
Hydrothermal Synthesis
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