No abstract

No abstract

In this study, a Na-x zeolite was synthesized by using metakaolin from Narathiwat kaolinite, amorphous silica from rice husk ash, and high CaO fly ash from the Mae Moh electrical plant by using the alkaline fusion method. The mixture of fly ash, amorphous silica and metakaolin was fused in NaOH followed by incubation at 70°C for 24 h. An amorphous silica from rice husk ash and metakaolin were added to high CaO fly ash to increase the SiO 2 /Al 2 O 3 ratio of fusion materials. The fused mixtures of high CaO fly ash, amorphous silica and metakaolin were mixed in the weight ratio of 1:3:6 giving a SiO 2 /Al 2 O 3 ratio of 3.25 to achieve a Na-x zeolite phase. The synthesized zeolite was characterized by XRD, SEM, FTIR, and BET techniques. The CEC and specific surface area of the Na-x zeolite were 420 meq 100 g −1 and 398 m 2 /g, respectively.

No abstract

Lanthanum cobalt oxide (LaCoO3) powders were prepared from mixtures of LaCl 3 · 7 H 2 O, CoCl 2 , and Na 2 CO 3 by grinding, heating, and washing operations. The reagents were mixed in a molar ratio of 1:1:2.5 in a planetary ball mill and milled at 300 rpm for 2 h. The milled samples were heated at various calcination temperatures and washed with distilled water. Thermogravimetric and differential thermal analysis were used to evaluate the optimum conditions for calcination. Phase formation was determined by X-ray diffraction (XRD) while specific surface area was measured by the BET method. The average particle size distribution was determined by a particle size analyser and morphology studied by scanning electron microscopy (SEM). The TG and DTA curves of the milled samples indicated that the formation of LaCoO3 occurred at temperatures in the range of 600°C to 800°C. XRD patterns showed clearly the formation of the LaCoO3 phase with perovskite-type structure at those temperatures. In addition, the results showed that the specific surface areas of the products decreased with increasing calcination temperature, while the average particle size D [4,3] increased. Furthermore, SEM micrographs demonstrated that the particles were in an agglomerated form with mean primary particle sizes in the range of 0.3-0.6 µm.