Abstract
Particles size and other chemical properties of thorium and its oxide were investigated. Metallic thorium powders were prepared by the electrolysis of KTHF5 dissolved in 50% NaCl-KCl mixture. The crystal size of the powders decreased with the increasing current density. And the maximum distribution was found in the region of 40μ100μ in the distribution curve.
Various properties of the powders are summarized as follows ;
(1) Each particle is a single crystal and its growth direction is[111]of the face centred cubic.
(2) The powders have a high plasticity and good compressibility (better than copper).
(3) Briquett pressed under the press. of 3t/cm2 were easily sintered at 1200°during 2hr.
(4) As the method of production of the powders, the hydride process is considered to be most profitable, because decontamination of the salt from the minor crystal is rather difficult.
To study the various properties of thorium oxide, temperature dependency of emanation values were measured in the process of the calcination of the oxalate and other compounds.
Dehydration process and the particle size distribution were clearly seen from these experiments. It is also concluded that the Hahn's emanation method is a good experimental tool for the studies of powder metallurgy, ceramics and surface phenomenae of other substances.
