- Cplav A-286 -1,4980
- Rohr hitzebeständige Backformen
- Greek Ascoloy 418
- Rohr korrosionsbeständig
Rare metals are defined as metals with an abundance in the earth's crust below 0.1%. Perhaps one will be surprised to discover that common metals such as copper, zinc, lead and nickel, whose production is constantly increasing, are geochemically rare and are on a par with gold, silver and platinum. Most experts believe that serious difficulties will arise primarily with the metals of this group and that they are capable of "challenging" the development of technology. Indeed, the lack of some of them is already being felt. The production of silver and gold no longer meets the needs of the industry, therefore, the dumps and tailings of former mining enterprises are involved in processing.
Rare metals are a group of vital elements that in our century have accelerated the development of such technical wonders as the generation and transmission of electricity, telegraph, radio, television, aeronautics, rocketry and nuclear power. So, without a wide supply of copper, the electric power industry would develop much more slowly. The possibility of depletion of rare metals threatens not only existing technical and technological wonders, but probably also those that are still being created.
The relative abundance of rare metals in the earth's crust is small, but their total amounts are still quite significant, since the crust itself is large in size. Therefore, it would seem to make sense to consider the "average" rock as a potential source of rare metals. By the way, such proposals have already been made. However, the huge volumes of rock that would have to be processed for this, and the enormous amount of energy required for crushing, preclude the possibility of this project. How unprofitable such an enterprise would be can be seen from the table, in which the monetary expressions of the amount of rare metals in 1 ton of granite are given.