thorium(IV), sorbent, sorption, desorption, clay

The article considers the danger of thorium due to its radioactive toxicity. There has been proved the diversity of thorium compounds and the influence of thorium on a human body and the environment. A polymer chelating sorbent containing fragments of 4-amino - thiouracil has been investigated. An isotherm of thorium sorption with the sorbent is constructed and the optimal concentration conditions are determined: pH = 4; = 6 • 10–3 mol/l; Vob = 25 ml; msorb = 0.03 g; sorptive capacity (CE) = 1 163 mg/g. The degree of extraction of thorium(IV) ions under optimal conditions exceeds 95%. The developed technique was applied to extract thorium from clay. Studying sorption was carried out under static conditions using special equipment.

Unstable Endings

In 1896, Henri Becquerel (1852–1908) had discovered, by chance, the phenomenon of radioactivity, after he found that uranium salts left on top of covered photographic plates produced an image on the plates when they were later developed. Soon afterwards, thorium was also found to be radioactive. In 1898 Marie Curie (née Sklodovska) realized that certain minerals were more ‘radioactive’ (a term she first introduced) than could be rationalized by the amount of uranium or thorium that they contained. She guessed that they might contain trace amounts of an even more radioactive element, and during the long purification process, she eventually realized that two such elements were present. The naming of the first of these, discovered in July 1898, is described by her daughter Eve Curie in her biography of her mother: . . . ‘You will have to name it,’ Pierre said to his young wife, in the same tone as if it were a question of choosing a name for little Irène [their first daughter]. The one-time Mlle Sklodovska reflected in silence for a moment. Then, her heart turning toward her own country which had been erased from the map of the world, she wondered vaguely if the scientific event would be published in Russia, Germany and Austria—the oppressor countries—and answered timidly: ‘Could we call it “polonium”?’ . . . Marie Curie named the element after her homeland, Poland, but the country did not exist as a separate entity at that time, and her choice was something of a political statement. The second element discovered by Marie and Pierre Curie was found to be millions of times more radioactive than uranium. This element they called ‘radium’ because of its intense radioactivity. Over three and a half years later, when they finally isolated a tenth of a gram of purified radium salts from tonnes of pitchblende ore, the Curies were delighted to find that the substance was spontaneously luminous. After the discovery that uranium and thorium were radioactive, in September 1899, Ernest Rutherford (1871–1937) made a further discovery: ‘In addition to this ordinary radiation, I have found that thorium compounds continuously emit radio-active particles of some kind, which retain their radio-active powers for several minutes.

Properties of Thorium Compounds: Application of Interionic Potential Theory

In the present work structural and mechanical properties of ThC and ThO compounds have been carried out using desirable modified inter-ionic potential theory (MIPT), which parametrically includes the effect of Coulomb screening. The transition from rock salt to caesium chloride occurs around 40.0 GPa and 65.0 GPa in the case of ThC and ThO respectively. We have also calculated bulk (B0), Young (E), and shear moduli (G), Poisson ratio (υ) and anisotropic ratio (A) in NaCl-type structure for these compounds and differentiate them with other experimental and theoretical results which show a good agreement.

High-pressure study of binary thorium compounds from first principles theory and comparisons with experiment

The high-pressure structural behaviour of a series of binary thorium compounds ThX(X= C, N, P, As, Sb, Bi, S, Se, Te) is studied using the all-electron full potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximation (GGA) for the exchange and correlation potential. The calculated equlibrium lattice parameters and bulk moduli, as well as the equations of state agree well with experimental results. New experiments are reported for ThBi and ThN. Calculations are performed for the ThXcompounds in the NaCl- and CsCl-type crystal structures, and structural phase transitions from NaCl to CsCl are found in ThP, ThAs, ThSb and ThSe at pressures of 26.1, 22.1, 8.1 and 23.2 GPa, respectively, in excellent agreement with experimental results. ThC, ThN and ThS are found to be stable in the NaCl structure, and ThBi and ThTe in the CsCl structure, for pressures below 50 GPa. The electronic structures of the ThXcompounds are studied using the quasiparticle self-consistentGWmethod (G: Green function,W: dynamically screened interaction).