Ion exchange investigation for recovery of uranium from acidic pregnant leach solutions

The article describes studies on the separation of uranium from acid pregnant leach solutions obtained from Polish uranium ores: dictyonema shales and sandstone rocks. Ion exchange chromatography was applied for uranium sorption, using commercially available, strongly basic anion exchanger, Dowex 1. In model experiments, the influence of degree of crosslinking of Dowex 1 on the efficiency of uranium extraction was investigated. The effect of H2SO4 concentration on the breakthrough curve of uranyl ions for the Dowex 1 resins, of different crosslinking: X4, X8 and X10, was examined. Unexpectedly high increase of exchange capacity of uranium was observed in case of Dowex 1X10. This gives potential opportunity of improving the effectiveness of uranium recovery process. Applying column packed with Dowex 1X10, ‘yellow cake’ with ca. 92% yield and high purity of recovered uranium was obtained. A block diagram of the procedure for uranium and lanthanides extraction from acidic leach liquor has been proposed.

V.—On a new Trilobite from the Dictyonema-shales of the Malvern Hills

In the collection made by the late Dr. Grindrod, now in the Geological Museum at Oxford, there is a minute species of trilobite, represented by two specimens, obtained from the Dictyonema-shales of the Malverns. This form was referred by Dr. Callaway to Shumardia (Conophrys) Salopiensis, Call.; but a careful study of the two specimens, aided by the removal of a small fragment of shale which partly concealed the more complete example, has shown the distinctness of the trilobite from Shumardia, and from any other genus known to the writer. Owing to the kindness of Professor Sollas I have been enabled to make a thorough examination of the specimens. The preservation is fairly good, but much of the actual test has been lost, and both fossils are largely in the form of internal casts. In the more complete but somewhat smaller example, which may be taken as the type-specimen, the whole trilobite is preserved (Fig. 3); in the second specimen little more than the thorax and pygidium is seen (Fig. 4).