Preparation PAC And Analysis Crystal Structure And Preparation PAS At75℃

In the study of poly aluminum speciation, the distribution and transformation mechanism of aluminum morphology has been a hot area of researching. In order to understand the the distribution and transformation mechanism ultimately of poly aluminum morphology, preparation the pure poly-aluminum compounds as much as possible and analyzing the crystal structure were the most effective way undoubtedly. Our group had been made great progress in preparation of poly aluminum pure crystalline and analysis of crystal structure.Twenty kinds of poly aluminum compounds have been synthesized successfully containing PAC, PAS, nitrate, bromide and iodide. And more poly aluminum morphological structures such as Al4&Al1, P-Al13, S-K-Al13and S-Al32were analyzed.In this thesis, the solid-liquid equilibrium diagram of AlC13-Al2O3-H2O at75℃was drawn by means of wet dregs. And under the guidance of the phase diagram, Al5Cl3(OH)12·7H2O was prepared with the purity of97.32%. A15C13(OH)12·4H2O was prepared with the purity of81.33%by continuing to evaporate the mother liquor which the product was filtered. Al10Cl4(OH)26·16H20with the purity of91.15%was prepared successful by washing Al5Cl3(OH)12·7H2O with hot water. Three poly aluminum species were characterized by chemical analysis, powder XRD phase analysis, infrared spectroscopy and thermal analysis.Crystal structure of Al5Cl3(OH)12·7H2O had been analyzed with the Rietveld method. The result shows that the crystal is an infinite structure by three-dimensional mesh state. From its minimum repeating units [Al10(OH)24(H2O)6]6+(P-Al10), we are very easy to see that is one product during P-Al13([Al13(OH)24(H2O)24]15+) processing. They form the three-dimensional aggregates by sharing the three aluminum oxygen octahedral on one side of seven aluminum plates which is vertical with c-axis after discarding the three aluminum oxygen octahedral on the other side. The three-tier structure is formed by two sides of P-Al1O linking to three equivalent form and repeat infinitely along the c-axis direction. The anion filled into the mesh and fixed through strong hydrogen bonds.In the study of poly aluminum sulfate, we usually get crystal of the poly aluminum sulfate by joining sulfate ions into poly aluminum solution which has been having hydrolysis polymerization. The poly aluminum sulfate crystals are so few using this method up to today that restricting the study of the speciation of poly aluminum. We synthesized NaAl3(SO4)2(OH)6by the method of captured by Na2SO4.This paper didn’t making too much characterization of NaAl3(SO4)2(OH)6because the structure of this material had been reported in detail. We prepared Al3(SO4)2(OH)5·9H2O by direct synthesis. Its structure will be analysed.