Europium fluorescence light tubes

There are only a few commercial uses for europium. Europium oxide, (Eu O ), a compound of europium, is added to infra-sensitive phosphors to enhance the red colors on TV and computer-monitor picture tubes. It is also added to fluorescent light tubes to increase their efflciency, as well as to some materials to make lasers. Since it is a good neutron absorber, it is part of nuclear reactor control rods. Europium is an additive to the glue used on postage stamps, thus making it possible for the electronic sorting machines in U.S. postal offices to read the stamps. 

Lanthanide metals were also successfully extracted from their oxides with a high pressure mixture of TBP-HNO3-H2O-CO2 (12). We applied this technique to extract europium from the additives contained in fluorescence light tubes. The additives were recovered as white powder by crashing the glass tubes. An experimental study was performed with a similar apparatus as shown in Figure 6. The results of extraction of europium are given in Table 1 as well as the experimental conditions. In Ref. (12), the recovery yield approached 100% easily, but relatively low recoveries... 

The perfection of phosphors using blue emissions from divalent europium, green emissions from trivalent terbium coactivated by cerium, and red from trivalent europium has made it possible to make trichromatic fluorescent tubes recently miniaturized in the form of compact lights for use in the home. 

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