I am sure that many people have told you of the green nature of wind power, it is sold to the public as the ultimate green energy production system. It has reached the point at which it seems like nobody is allowed to say anything bad about wind farms, but we need to keep our wits about ourselves.
Many high tech and green gadgets need rare earths (lanthanides), the name is a bit of a misnomer some of the lanthanides are very common in the earth. But some of them are very rare elements, the worst bit is that the rare ones are the more useful ones. For example the red phosphor in a colour TV is traditionally europium doped yttrium oxide or europium doped yttrium oxysulfide. Europium is a rare lanthanide which often forms compounds which emit red light.
Now with many gadgets such as electric cars and windmills people think they are green because they do not release any pollution during use, it is important to understand that a gadget such as an electric car is not a “zero emissions vehicle” it is an “emissions elsewhere vehicle”. One emission type are those which occur during the use of the machine and the others are those associated with the production and final disposal of the object.
If we ignore the emissions during the building of the gadget and its disposal then a nuclear power plant is perfectly green, it emits next to no pollution during use. It is only during the fuel production, building of the plant and the disposal of the fuel that the releases of pollution occur. It is clear that we must consider the whole lifecycle of the parts of the system.
In the case of the lanthanides it is important to understand that the processing of lanthanide ores produces radioactive waste, the problem is that much of the world’s lanthanides are in thorium rich minerals such as the monazite phosphate minerals. As a result when monazite is processed often radioactive waste is produced.
The nasty thing about natural radioactivity in rocks and minerals (harmless or cute sounding) is that it tends to be alpha emitting and often mobile in the form of radon / radium. On the other hand much of the radioactivity in the back end of the nuclear fuel system (scary sounding reactor waste) is short lived beta / gamma emitting fission products and a little alpha emitting waste. Much of this alpha emitting muck is plutonium, while plutonium might sound like a total nightmare it is important to note that it is very immobile in the form of oxide fuel. Firstly it is very insoluble in water and secondly plutonium absorbs very well onto mineral surfaces. To use some non technical language it sticks like glue to mineral surfaces, thus it will not migrate through soil and rocks with ease. Once the plutonium is buried then it will be locked up in the rocks for many thousands of years.
On the other hand radium and radon can move around in water with ease, these elements will not bind so well to mineral surfaces. The waste from lanthanide ore processing is sometimes codenamed TENORM, this means Technologically Enhanced Naturally Occurring Radioactive Material. This TENORM is a major pain in the oil / gas industry and in the ore processing industry.
The best way to reduce the production of this radioactive waste is to recycle lanthanides, by reusing lanthanides instead of mining ore the volume of radioactive waste will be reduced. If you want to support green devices such as hybrid cars and windmills then it is up to you, but I would urge you to lobby for the valuable metals and other materials to be recycled when these products reach the end of their useful lives. If no sensible recycling method exists then a need exists for more research on recycling, one of the things which I am involved with at Chalmers is the Industrial Materials Recycling section. Here we study the recycling of that which can not be currently recycled.