hyderconsulting said:
I think I can clear up the confusion somewhat here about this radioactivity question about the rare earths. As I remember they are mined from a material (ore) known as Monazite Sand which contains all the rare earths and also thorium. It is the thorium which is radioactive, a beta emitter. That's where the radioactivity comes from. When the rare earths are first extracted to concentrate them the first step is to separate the thorium from them. By the way, your smoke detector in your home uses the radioactive element Americum which is quite toxic and poisonous so don't swallow any parts of your smoke detector. Regards, Chris.
A man in America was actually going through the phases of building a nuclear reactor successfully in his shed using lots of parts from smoke detectors under the guidance of old dictionaries and science mags from the 50's, his experiment went wrong and that street is gonna have unacceptable levels of radiation for thousands of years now.
heres a link. http://www.wesjones.com/silverstein1.htm
and for those that cant be bothered to read it take a look at this paragraph.
''To obtain americium-241, David contacted smoke-detector companies and claimed that he needed a large number of the devices for a school project. One company agreed to sell him about a hundred broken detectors for a dollar apiece. (He also tried to "collect" detectors while at scout camp.) David wasn't sure where the americium-241 was located, so he wrote to BRK Electronics in Aurora, Illinois. A customer-service representative named Beth Weber wrote back to say she'd be happy to help out with "your report." She explained that each detector contains only a tiny amount of americium-241, which is sealed in a gold matrix "to make sure that corrosion does not break it down and release it." Thanks to Weber's tip, David extracted the americium components and then welded them together with a blowtorch.''