To the problem of chemical preparation of lanthanoid oxychlorides

Formation of La-Ho oxychlorides from the interaction of the rare-earth elements sesqui alteral oxides and gaseous chlorine was investigated. The temperatures of starting reactions between La-Ho oxides and gaseous chlorine were found by thermographic method. They are 290 deg (La2O3), 310 deg (Nd2O3), 400 deg (Sm2O4), 320 deg (Eu2O3), 340 deg (Gd2O3), 530 deg (Dy2O3), and 617 deg (Ho2O3). For Eu-Lu oxides it was impossible to measure the temperatures of starting chlorination by such method. The thermogravimetric and chemical analyses showed that the transformation of oxides into oxychlorides occurs at a measurable rate in the thesis temperatures rare - earth element oxychlorides are of some heavy lanthanides into oxychlorudes was incomplete: 92.5%. The chlorination products of REE oxides were subjected to X-ray, microscopic and chemical analyses. Investigations show that the oxides reactivities towords chlorine enhance from La2O3 to Eu2O3, then decrease to Lu2O3. The Yb2O3 is an exception since it has somewhat higher activity with respect to the neighbouring lanthanides. The observed values of apparent activation energies of the processes investigated decrease from La to Eu (from 21 - 17 kcal/mole) with subsequent growth to Lu (to 80 Kcal/mole)