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Abstract  

A precipitation method was used to prepare amorphous mixed zirconium-titanium phosphates with various titanium contents. In this way the acidic solutions of ZrOCl2.8H2O and TiCl4 in various ratios were rapidly mixed with a phosphoric acid solution under continuous stirring. The resulting precipitate, characterized as [ZrxTi/1–x//HPO4/2.n H2O] was contacted with water of ethanol, then washed to pH 3.0 and dried at room temperature. The samples were irradiated with -rays of a60Co source giving a 6.6×107 Gy total dose. The thermal, chemical and ion-exchange properties of irradiated samples were investigated.

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Abstract  

Solid amorphous zirconium phosphate /ZPa/ and hafnium phosphate /HPa/ are mixed with an excess of solid oxalic acid dihydrate and are digested in molten oxalic acid. Then oxalic acid is removed by extraction or by heating. The residue is washed with dilute HCl /0.01M/ and redistilled water. By this method -ZP and -HP is formed from amorphous ones.

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Abstract  

Mixed zirconium-titanium phosphates were synthesized by various methods and under various conditions. The effect of these conditions on the selectivity of synthetized samples toward the transition metal ions was investigated. It was found that the kd values are independent of the metal concentration and they give the selectivity order Zn2+>Cu2+ Co2+, Ni2+>Mn2+.

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Abstract  

The comparison of data of thermal analysis partly with XRD and/or analytical results permits determination of the exact quantity of crystal water of the investigated samples having quite different behaviour. The compositions of the samples were determined from the results of thermal analysis. Furthermore, the data help elucidate the behaviour of various crystalline materials and also their intercalates during heat treatment.

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Thermal behaviour of acidic salts of mixed tetravalent metals

V. Thermal decomposition of amorphous glassy-type zirconium-titanium phosphate

Journal of Thermal Analysis and Calorimetry
Authors:
L. Szirtes
,
S. Shakshooki
,
Z. Pokó
, and
L. Pavlovszki

The mixed amorphous glassy-type zirconium-titanium phosphates contain various quantities of adsorbed water per molecule unit. Pure zirconium phosphate lost the structural water in two steps. This character disappeared with increasing titanium content. However, glassy titanium phosphate lost its water in two steps at lower temperature in comparison with glassy zirconium phosphate.

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Mixed insoluble acidic salts of tetravalent metals

IX. Effect of γ-radiation and drying temperature on mixed glassy type hafnium-titanium phosphates

Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Shakshooki
,
Y. Elmismary
,
A. Dehair
, and
L. Szirtes

Abstract  

Mixed amorphous glassy type hafnium-titanium phosphates have been prepared. The composition and ion exchange capacity of the samples were investigated before and after -irradiation. In addition, the effect of temperature on the ion exchange capacity of the samples was determined. Based on the data obtained, neither the composition nor the ion exchange behavior of the investigated materials was altered by the irradiation. An increased drying temperature led to a decrease in the ion exchange capacity of the samples.

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Abstract  

The selectivity of glass type mixed Zr+Ti phosphates with various Ti contents has been investigated toward rare earth metal ions. The kd values were determined by radiotracer technique both in HCl and HNO3 solutions of various concentrations. At room temperature and at pH=4 the following selectivity orders were found: Yb>TmEu>Sm>La (HCl) and Eu>La>Sm>Yb>Tm (HNO3).

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Thermal behaviour of acidic salts of mixed tetravalent metals

IV. Thermal decomposition of crystalline zirconium-titanium phosphate prepared through the fluorine complex (HF method)

Journal of Thermal Analysis and Calorimetry
Authors:
S. Shakshooki
,
S. Khalil
,
A. Abuhamaira
,
L. Szirtes
, and
Z. Pokó
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Abstract  

Solid amorphous mixed zirconium-titanium phosphates, with general formula ZrxTi/1–x//HPO4/2.n H2O/ where x=0.1–1, and n=3–5/, are mixed with an excess of solid oxalic acid dihydrate and digested in molten oxalic acid. Then oxalic acid is removed by extraction and the residue washed with dilute /O.OlM/ HCl solution and bidistilled water. As a result of this method, crystalline mixed zirconium-titanium phosphate is formed.

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Abstract  

Mixed crystalline zirconium-titanium arsenates ZrxTi(1–x) (HAsO4)2·H2O and harnium-titanium arsenates HfxTi(1–x) (HAsO4)2 H2O (where x=0–1) of various compositions with different Zr/Ti or Hf/Ti ratios have been prepared. The compounds have been characterized by X-ray, thermal analysis, chemical analysis, and pH-titrations. For powder X-rays, the compounds appear to be homogeneous crystalline materials with structures similar to -ZrP, -TiP or -ZrTiP. The thermograms show a loss of approximately two moles of H2O, followed by a small loss of O2 with probable formation of ZrO2, As2O3, HfO2, As2O3, ZrO2, As2O5, HfO2, As2O5 from which As2O3 and As2O5 are practically sublimed in two steps. The exchange capacities at r.t. are generally similar to -ZrP and -TiP but are found to be much lower in value.

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