The Influence of Agitation Speed on the Morphology and Size Particle Synthesis of Zr(HPO<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O from Mexican Sand

Abstract

Mexican zirconium sand has been envisaged like a source of zirconium compounds. The main product obtained is zircon (ZrSiO 4), which has a high raw material value. During a mineralogical purification sand process with hydrofluoric acid, a liquor was obtained as the by product. This liquor was dripped over hot phosphoric acid to obtain zirconium hydrogen phosphate Zr(HPO 4) 2. H 2 O (α-ZP) which has taken considerably attention due to its wide application. Both products zircon and α-ZP were analyzed as for structure and purity using analytic techniques. X-Ray diffraction revealed that zircon and α-ZP were polycrystalline materials. Scanning Electron Microscopy indicated that α-ZP formed particles and aggregates in different shapes and size distributions depending on the condensing way and the agitation speed. Furthermore, thermogravimetric analysis demonstrated that the α-ZP phases present different hydrated levels. FTIR spectra were obtained to identify the corresponding P-O stretching vibration from the α-ZP and the specific surface areas were calculated by BET method.

Continuous Liquid-Phase Upgrading of Dihydroxyacetone to Lactic Acid over Metal Phosphate Catalysts

“…The broad band around 750 cm –1 in the spectra of NbPO and ZrPO is attributed to the P–O–P vibration of diphosphate groups . The ZrPO band at 933 cm –1 was already observed in the α-zirconium hydrogen phosphate FTIR spectrum . The peak position of asymmetric P–O stretching vibrations usually increases in energy with the increasing ionic radius of the cation, which is in agreement with our experimental results [Nb (215 pm) < Zr (230 pm) < La (250 pm) → 981 cm –1 < 1013 cm –1 < 1072 cm –1 , respectively].…”

“…In fact, the strong crystal field of LaPO splits the asymmetrical P–O stretching (ν 3 ) into four bands detectable at 1072, 1043, 1021, and 988 cm –1 and the deformation vibration (ν 4 ) into three peaks at 613, 580, and 536 cm –1 , respectively. − Thanks to the high LaPO crystal field, even the symmetrical stretching vibration (ν 1 ) at 944 cm –1 was resolved, although it should be infrared-forbidden . The broad band around 750 cm –1 in the spectra of NbPO and ZrPO is attributed to the P–O–P vibration of diphosphate groups . The ZrPO band at 933 cm –1 was already observed in the α-zirconium hydrogen phosphate FTIR spectrum .…”

Synthesis of Nano-Ni by Liquid Reduction Method in a Combined Reactor of Rotating Packed Bed and Stirred Tank Reactor

“…Thus, a higher rotation speed may lead to the change of nano-Ni’s morphology and increase in average particle size of nano-Ni. The similar phenomenon has been also found in the preparation of nano-Ni in the STR and the preparation of other particle in STR. , …”

“…The similar phenomenon has been also found in the preparation of nano-Ni in the STR and the preparation of other particle in STR. 35,36 4.2. Effect of NaBH 4 Concentration.…”

The Evolution of Morphology and Properties of Films Obtained by Anodizing Zirconium

“…In the last years, microstructural characterization of Zr alloys with titanium and other valve metals has been deeply investigated for their potential mechanical and biomedical applications [6,7]. Previous studies [8] have shown that anodizing Zr in H 3 PO 4 produces apart from ZrO 2 a superficial stratum rich in phosphates and other studies revealed [9] that the phosphates are usually formed as zirconium hydrogen phosphate (Zr(HPO 4 ) 2 .H 2 O), alpha phase (α-ZP) being the more common.…”