Extractive Metallurgy and National Policy

Hydrometallurgical technology offers a unique possibility for developing countries to exploit their mineral resources locally instead of shipping them as concentrates. Production plants may start on a small scale with small capital investment then increase productivity later when the economy permits without financial penalty. This is in contract to smelting operations which necessitates large scale production from the start with high capital investment that may not be available locally.

反映发展史的邮票——铀的发展史

邮票已成为一种有价值的沟通手段,作为历史印记起着多种作用。各国用邮票记录重大事件、纪念杰出人物和功绩,以及突出重大进展。在邮票上能够找到许多历史事实(有时是模糊的);