Synthesis of Dawsonite (Basic Sodium Aluminum Carbonate) from Colloidal Earth (Aoolphane) by Treatment with Acid and Alkali

膠質土酸, Alkali 處理에 의한 Dawsonite의 合成에 관한 硏究

  • 권상욱 (한양대학교 문리과대학 화학과)
  • Published : 19690600

Abstract

Aoolphane was treated with 30% Hydrochloric acid at $18^{\circ}C$ for two hows with stirring in order to obtain the insoluble form of SiO2 gel and to extract quantitatively both $Al_2O_3$as and $Fe_2O_3AlCl_3{\cdot}6H_2O Fe$ and $Cl_3{\cdot}6H_2O$ forms, respectively, at the same time. $SiO_2$ gel was filtered and to the filterate Ammonia was added to precipitate $Al(OH)_3[Fe(OH)_3 Contaminated ]$ The precipitate was separated by filteration and the filterate was recovered as the form of $NH_4Cl$. The precipitate was treated with 200g (NaOH)/l Concentration of NaOH a little excessively to the equivalent at $65~70^{\circ}C$ as $Fe(OH)_3$ formed was insoluble, it was filtered of and to the filterate containing $NaAl(OH)_4(OH_2)_2$Carbon dioxide gas was bubbled at $50^{\circ}C~90^{\circ}C$ to obtain the precipitate with excellent filterability and crystallinity. The product was certified to be Dawsonite $(NaAl(OH)_2CO_3)$ by X-Ray diffraction analysis at below $40^{\circ}C$, when $CO_2$ gas was bubbled into the relatively lower concentration of $NaAl(OH)_4(OH_2)_2$ solution, the precipitate of very fine particles was formed, which was hard to filter and with the Composition of $\alpha-Al_2O_3-H_2O$ (Boehmite).

Keywords

References

  1. Bullentin of sci Eng. v.41 S.W. Kwon;Ishikawa
  2. 早稻田應化誌 v.21 田中;堀田
  3. The petrology of Dawsonite at the type locality v.8 Stevenson, J.s.;Stevenson, L.S.
  4. ASTM card 12-449
  5. 日本化學會講演 Sang-Wook, Kwon
  6. 日本粘土學會討論會講演要旨 Sang-Wook, Kwon
  7. Aluminium 工業 北川三郞
  8. ASTM card 5-0190
  9. Tonerde und Aluminium v.I W-Fulda;H. Ginsberg
  10. 電氣化學(日本化學會) v.28 舟木好右衛門;淸水
  11. ASTM Card 12-449
  12. canadian mineralogist v.5 A.J. Frueh, J.R.;J.P. Golighthy